Heterogeneous weighted overlap-add windowing and filtering for orthogonal frequency division multiplexing waveforms

Techniques for processing of symbols (e.g., orthogonal frequency division multiplexing (OFDM) or single carrier-frequency division multiple access (SC-FDMA) symbols) provide enhanced out-of-band (OOB) suppression of the symbols and also provide reduced inter-symbol interference (ISI) between a symbol and a subsequent symbol. Multiple frequency tones of a symbol may be divided into two or more subsets of tones. For example, subsets of tones associated with a head portion or a tail portion of an OFDM symbol may be processed with a relatively long weighted overlap-add (WOLA) weighting length or filtering length, and a subset of tones associated with a center portion of the OFDM symbol may be processed with a relatively short WOLA weighting length or filtering length. Such heterogeneous processing of tones within a symbol may provide enhanced inter-channel interference (ICI) and improved OOB suppression and also provide reduced ISI for the center tones of the symbol.

INTRODUCTION

The present disclosure, for example, relates to wireless communication systems, and more particularly to techniques for heterogeneous weighted overlap-add (WOLA) windowing and filtering for orthogonal frequency division multiplexing (OFDM) and single carrier-frequency division multiple access (SC-FDMA) waveforms.

In some examples, a wireless multiple-access communication system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, otherwise known as user equipment (UEs). In a Long-Term Evolution (LTE) or LTE-Advanced (LTE-A) network, a set of one or more base stations may define an eNodeB (eNB). In other examples (e.g., in a next generation or 5G network), a wireless multiple access communication system may include a number of smart radio heads (radio heads (RHs)) in communication with a number of access node controllers (ANCs), where a set of one or more radio heads, in communication with an ANC, may define an eNB. A base station or radio head may communicate with a set of UEs on downlink channels (e.g., for transmissions from a base station or radio head to a UE) and uplink channels (e.g., for transmissions from a UE to a base station or radio head).

In some examples, a UE and a network device (e.g., a network access device (e.g., a radio head, a base station, an eNB, or an ANC) may communicate using symbols (e.g., OFDM or SC-FDMA symbols). Many systems that transmit using symbols may perform signal processing to help suppress out-of-band (OOB) transmissions, such as through weighted overlap-add (WOLA) processing of transmissions. Such techniques may help suppress OOB transmissions, but may increase inter-symbol interference at a subsequent symbol.

SUMMARY

The present disclosure describes techniques for processing of symbols (orthogonal frequency division multiplexing (OFDM) or single carrier-frequency division multiple access (SC-FDMA) symbols) to provide enhanced out-of-band (OOB) suppression of the symbols and also provide reduced inter-symbol interference (ISI) between a symbol and a subsequent symbol. In some examples, multiple frequency tones of a symbol may be divided into two or more subsets of tones, and different subsets of tones may be processed using one or more different processing parameters. In some examples, subsets of tones associated with a head portion or a tail portion of a symbol may be processed with a relatively long weighted overlap-add (WOLA) weighting length or filtering length, and a subset of tones associated with a center portion of the symbol may be processed with a relatively short WOLA weighting length or filtering length. Such heterogeneous processing of tones within a symbol may provide enhanced inter-channel interference (ICI) and improved OOB suppression and also provide reduced ISI for the center tones of the symbol.

A method of wireless communication is described. The method may include identifying a set of tones of a first orthogonal frequency division multiplexing (OFDM) symbol, a first subset of the set of tones, and a second subset of the set of tones, applying a first type of weighting window to the first subset of the set of tones and a second type of weighting window to the second subset of the set of tones in a weighted overlap and add (WOLA) procedure, the second type of weighting window being longer than the first type of weighting window, obtaining a first transmission waveform for the first OFDM symbol based at least in part on the applying, and transmitting the first transmission waveform.

An apparatus for wireless communication is described. The apparatus may include means for identifying a set of tones of a first OFDM symbol, a first subset of the set of tones, and a second subset of the set of tones, means for applying a first type of weighting window to the first subset of the set of tones and a second type of weighting window to the second subset of the set of tones in a WOLA procedure, the second type of weighting window being longer than the first type of weighting window, means for obtaining a first transmission waveform for the first OFDM symbol based at least in part on the applying, and means for transmitting the first transmission waveform.

Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to identify a set of tones of a first OFDM symbol, a first subset of the set of tones, and a second subset of the set of tones, apply a first type of weighting window to the first subset of the set of tones and a second type of weighting window to the second subset of the set of tones in a WOLA procedure, the second type of weighting window being longer than the first type of weighting window, obtain a first transmission waveform for the first OFDM symbol based at least in part on the applying, and transmit the first transmission waveform.

A non-transitory computer readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to identify a set of tones of a first OFDM symbol, a first subset of the set of tones, and a second subset of the set of tones, apply a first type of weighting window to the first subset of the set of tones and a second type of weighting window to the second subset of the set of tones in a WOLA procedure, the second type of weighting window being longer than the first type of weighting window, obtain a first transmission waveform for the first OFDM symbol based at least in part on the applying, and transmit the first transmission waveform.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the first subset of the set of tones comprises a center portion of the set of tones and the second subset of the set of tones comprises a head portion of the set of tones.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying a third subset of the set of tones comprising a tail portion of the set of tones, and wherein the applying further comprises applying a third type of weighting window to the third subset of the set of tones in the WOLA procedure to obtain the first transmission waveform. In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the third type of weighting window is longer than the first type of weighting window.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for selecting the first type of weighting window for a first weighting procedure to be performed on the first subset of the set of tones and selecting the second type of weighting window for a second weighting procedure to be performed on the second subset of the set of tones. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for performing the first weighting procedure on the first subset of the set of tones to obtain a weighted first subset of samples corresponding to the first subset of the set of tones and performing the second weighting procedure on the second subset of the set of tones to obtain a weighted second subset of samples corresponding to the second subset of the set of tones. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for overlapping and adding the weighted first subset of samples and the weighted second subset of samples to obtain the first transmission waveform.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, performing the first weighting procedure comprises: adding a cyclic prefix and a first extension length to a first subset of time domain samples corresponding to the first subset of the set of tones, the first extension length corresponding to the first type of weighting window. In some examples of the method, apparatus, or non-transitory computer-readable medium described above, performing the second weighting procedure comprises: adding the cyclic prefix and a second extension length to a second subset of time domain samples corresponding to the second subset of the set of tones, the second extension length corresponding to the second type of weighting window.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for repeating the identifying and the applying for a second set of tones of a second OFDM symbol to obtain a second transmission waveform for the second OFDM symbol. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for overlapping and adding the first transmission waveform and the second transmission waveform. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting the overlapped and added first transmission waveform and second transmission waveform.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, an amount of overlapping of the first transmission waveform and the second transmission waveform is determined based at least in part on a longest length of the first type of weighting window or the second type of weighting window.

A method of wireless communication is described. The method may include identifying a set of tones of a first OFDM symbol, a first subset of the set of tones, and a second subset of the set of tones, applying a first filter length to the first subset of the set of tones and a second filter length to the second subset of the set of tones in a bandpass filtering procedure, the second filter length being longer than the first filter length, obtaining a first transmission waveform for the first OFDM symbol based at least in part on the applying, and transmitting the first transmission waveform.

An apparatus for wireless communication is described. The apparatus may include means for identifying a set of tones of a first OFDM symbol, a first subset of the set of tones, and a second subset of the set of tones, means for applying a first filter length to the first subset of the set of tones and a second filter length to the second subset of the set of tones in a bandpass filtering procedure, the second filter length being longer than the first filter length, means for obtaining a first transmission waveform for the first OFDM symbol based at least in part on the applying, and means for transmitting the first transmission waveform.

Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to identify a set of tones of a first OFDM symbol, a first subset of the set of tones, and a second subset of the set of tones, apply a first filter length to the first subset of the set of tones and a second filter length to the second subset of the set of tones in a bandpass filtering procedure, the second filter length being longer than the first filter length, obtain a first transmission waveform for the first OFDM symbol based at least in part on the applying, and transmit the first transmission waveform.

A non-transitory computer readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to identify a set of tones of a first OFDM symbol, a first subset of the set of tones, and a second subset of the set of tones, apply a first filter length to the first subset of the set of tones and a second filter length to the second subset of the set of tones in a bandpass filtering procedure, the second filter length being longer than the first filter length, obtain a first transmission waveform for the first OFDM symbol based at least in part on the applying, and transmit the first transmission waveform.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the first subset of the set of tones comprises a center portion of the set of tones and the second subset of the set of tones comprises a head portion of the set of tones. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying a third subset of the set of tones comprising a tail portion of the set of tones, and wherein the applying further comprises applying a third filter length to the third subset of the set of tones in the bandpass filtering procedure to obtain the first transmission waveform.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the third filter length is longer than the first filter length. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for selecting the first filter length for a first bandpass filtering procedure to be performed on the first subset of the set of tones and selecting the second filter length for a second bandpass filtering procedure to be performed on the second subset of the set of tones. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for performing the first bandpass filtering procedure on the first subset of the set of tones to obtain a filtered first subset of samples corresponding to the first subset of the set of tones and performing the second bandpass filtering procedure on the second subset of the set of tones to obtain a filtered second subset of samples corresponding to the second subset of the set of tones. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for overlapping and adding the filtered first subset of samples and the filtered second subset of samples to obtain the first transmission waveform.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, performing the first bandpass filtering procedure comprises: adding a cyclic prefix to a first subset of time domain samples corresponding to the first subset of the set of tones and bandpass filtering the cyclic prefix and the first subset of time domain samples based at least in part on the first filter length.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, performing the second bandpass filtering procedure comprises: adding the cyclic prefix to a second subset of time domain samples corresponding to the second subset of the set of tones. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for bandpass filtering the cyclic prefix and the second subset of time domain samples based at least in part on the second filter length.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for repeating the identifying and the applying for a second set of tones of a second OFDM symbol to obtain a second transmission waveform for the second OFDM symbol. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for overlapping and adding the first transmission waveform and the second transmission waveform. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting the overlapped and added first transmission waveform and second transmission waveform.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, performing the first bandpass filtering procedure comprises: adding a guard interval to a first subset of time domain samples corresponding to the first subset of the set of tones and bandpass filtering the guard interval and the first subset of time domain samples based at least in part on the first filter length.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, performing the second bandpass filtering procedure comprises: adding the guard interval to a second subset of time domain samples corresponding to the second subset of the set of tones. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for bandpass filtering the guard interval and the second subset of time domain samples based at least in part on the second filter length.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for repeating the identifying and the applying for a second set of tones of a second OFDM symbol to obtain a second transmission waveform for the second OFDM symbol. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for concatenating the first transmission waveform and the second transmission waveform. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting the concatenated first transmission waveform and second transmission waveform.

DETAILED DESCRIPTION

The present disclosure describes techniques for processing of symbols (e.g., orthogonal frequency division multiplexing (OFDM) or single carrier-frequency division multiple access (SC-FDMA) symbols) to provide enhanced out-of-band (OOB) suppression of the symbols and also provide reduced inter-symbol interference (ISI) between a symbol and a subsequent symbol. In some examples, multiple frequency tones of a symbol may be divided into two or more subsets of tones, and different subsets of tones may be processed using one or more different processing parameters. In some examples, subsets of tones associated with a head portion or a tail portion (e.g., edge tones) of a symbol may be processed with a relatively long weighted overlap-add (WOLA) weighting length or filtering length, and a subset of tones associated with a center portion of the symbol may be processed with a relatively short WOLA weighting length or filtering length. Such heterogeneous processing of tones within a symbol may provide enhanced inter-channel interference (ICI) and improved OOB suppression and also provide reduced ISI for the center tones of the symbol. Heterogeneous techniques as discussed herein may be used for both transmit and receive processing.

As indicated above, in some examples WOLA techniques may be used to reduce OOB through a relatively sharp roll-off of the transmitted waveform of a symbol. Such a WOLA technique may use a windowing mask having relatively soft edges at both sides, which results in a relatively sharp side-lope decay in the frequency domain, which may help to reduce inter-channel interference (ICI). The shape of the windowing mask in the time domain (at the edges) helps determine the power spectral density (PSD) of the waveform, and in many examples a raised-cosine edge window is used that provides a compromise between a straightforward implementation and the roll-off of the transmitted waveform. As also indicated above, one disadvantage of WOLA is that WOLA-OFDM waveforms may have relatively extended ISI in wireless channels with a relatively long delay spread. In some deployments, such as some next generation or 5G systems, different services (e.g., narrowband internet-of-things (NB-IOT) services, voice services, data services) may be multiplexed in the frequency domain such that some services may be relatively sensitive to ISI. Various examples of the present disclosure provide techniques for reducing ISI while also providing OOB suppression and reduced ICI.

When performing previous WOLA procedures, a transmitter may identify a symbol to be transmitted, and perform an inverse fast Fourier transform (IFFT) on frequency tones of the symbol and do a parallel to serial conversion of the IFFT output to obtain time samples corresponding to the symbol. The transmitter may then add a cyclic prefix (CP) to the time samples, and pad the beginning and end of the symbol time samples to provide an overlap extension at the beginning and the end of the symbol. A windowing mask, with soft right and left edges, may then be applied to provide a waveform for transmission of the symbol. Finally, adjacent symbols are overlapped and added in the edge transition region. A WOLA weighting length associated with the windowing mask may have an impact on the ISI between adjacent transmitted symbols, as well as on the amount of roll-off of the waveform. Thus, a relatively small WOLA weighting length may reduce the ISI effect but may not provide efficient OOB suppression.

As indicated above, examples of the present disclosure provide that frequency tones of a symbol may be divided into two or more subsets of tones, and different subsets of tones may be processed using one or more different processing parameters, such as different WOLA weighting lengths or filtering lengths. In some examples, subsets of tones associated with a head portion and/or a tail portion (e.g., edge tones) of a symbol may be processed with a relatively long WOLA weighting length, and a subset of tones associated with a center portion of the symbol may be processed with a relatively short WOLA weighting length. Such heterogeneous processing of tones within a symbol may provide enhanced ICI and improved OOB suppression at transmission edges, and also provide reduced ISI for the center tones of the symbol. The different portions of the symbol may be overlapped to form a transmission waveform for the symbol, which may be overlapped and added with adjacent symbol transmission waveforms.

In some examples, heterogeneous processing of a symbol may be used in conjunction with transmission filtering using a bandpass filter. In such examples, subsets of tones associated with a head portion or a tail portion of a symbol may be processed with a relatively long filter length (e.g., a relatively large number of samples or taps at a finite impulse response (FIR) filter), and a subset of tones associated with a center portion of the symbol may be processed with a relatively short filter length. Such heterogeneous processing of tones within a symbol may provide enhanced spectral shape for OOB suppression at transmission edges, and also provide reduced ISI for the center tones of the symbol. The different portions of the symbol may be overlapped to form a transmission waveform for the symbol. In some examples a CP may be added to the symbol transmission, and the transmission waveform for the symbol may be overlapped and added with adjacent symbol transmission waveforms. In certain examples, such a CP may simply be replaced by a guard interval, and the different portions of the symbol may be added to form the symbol transmission waveform which may simply be concatenated with other symbol transmission waveforms.

FIG. 1shows an example of a wireless communication system100, in accordance with various aspects of the disclosure. The wireless communication system100may include network access devices105, UEs115, and a core network130. The core network130may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the network access devices105(e.g., eNBs105-aor ANCs105-b) may interface with the core network130through backhaul links132(e.g., S1, S2, etc.) and may perform radio configuration and scheduling for communication with the UEs115. In various examples, the ANCs105-bmay communicate, either directly or indirectly (e.g., through core network130), with each other over backhaul links134(e.g., X1, X2, etc.), which may be wired or wireless communication links. Each ANC105-bmay also communicate with a number of UEs115through a number of smart radio heads (radio heads (RHs))105-c. In an alternative configuration of the wireless communication system100, the functionality of an ANC105-bmay be provided by a radio head105-cor distributed across the radio heads105-cof an eNB105-a. In another alternative configuration of the wireless communication system100, the radio heads105-cmay be replaced with base stations, and the ANCs105—may be replaced by base station controllers (or links to the core network130). The wireless communication system100may also include a mix of radio heads105-c, base stations, and/or other network access devices105for receiving/transmitting communications according to different RATs (e.g., LTE/LTE-A, 5G, Wi-Fi, etc.).

A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs115with service subscriptions with a network provider. A small cell may include a lower-powered radio head or base station, as compared with a macro cell, and may operate in the same or different frequency band(s) as macro cells. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell may cover a relatively smaller geographic area and may allow unrestricted access by UEs115with service subscriptions with a network provider. A femto cell also may cover a relatively small geographic area (e.g., a home) and may provide restricted access by UEs115having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in the home, and the like). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB or a home eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells (e.g., component carriers).

The wireless communication system100may support synchronous or asynchronous operation. For synchronous operation, the eNBs105-aand/or radio heads105-cmay have similar frame timing, and transmissions from different eNBs105-aand/or radio heads105-cmay be approximately aligned in time. For asynchronous operation, the eNBs105-aand/or radio heads105-cmay have different frame timings, and transmissions from different eNBs105-aand/or radio heads105-cmay not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

Each eNBs105-aand/or radio heads105-cmay provide communication coverage for a respective geographic coverage area110. The communication links125shown in wireless communication system100may include uplinks (ULs) from a UE115to a radio head105-c, and/or downlinks (DLs), from a radio head105-cto a UE115. The downlinks may also be called forward links, while the uplinks may also be called reverse links. Control information and data may be multiplexed on an uplink or downlink according to various techniques. Control information and data may be multiplexed on an uplink or downlink, for example, using TDM techniques, FDM techniques, or hybrid TDM-FDM techniques.

One or more of the UEs115may include a communication manager1415. In some examples, the communication manager1415may be an example of the UE Communication manager1415described with reference toFIG. 14. In some examples, the Communication manager1415may be used to generate an OFDM symbol transmission waveform and/or a SC-FDMA symbol transmission waveform using heterogeneous WOLA processing or filtering, in which a WOLA weighting length or filtering length may be different for different tones within the OFDM or SC-FDMA symbol.

One or more network devices (e.g., one or more of the radio heads105-c, base stations, eNBs105-a, or ANCs105-b, or a central node (e.g., an MME) of the core network130) may include a symbol communication manager1515. In some examples, the symbol communication manager1515may be an example of the base station symbol communication manager1515described with reference toFIG. 15. In some examples, the symbol communication manager1515may be used to generate an OFDM symbol transmission waveform and/or a SC-FDMA symbol transmission waveform using heterogeneous WOLA processing or filtering, in which a WOLA weighting length or filtering length may be different for different tones within the OFDM or SC-FDMA symbol.

Each communication link125may include one or more carriers, where each carrier may be a signal made up of multiple subcarriers (e.g., waveform signals of different frequencies) modulated according to one or more radio access technologies. Each modulated signal may be sent on a different subcarrier and may carry control information (e.g., reference signals, control channels, etc.), overhead information, user data, etc. The communication links125may transmit bidirectional communications using Frequency Division Duplexing (FDD) techniques (e.g., using paired spectrum resources) or Time Division Duplexing techniques (e.g., using unpaired spectrum resources). Frame structures for FDD (e.g., frame structure type 1) and TDD (e.g., frame structure type 2) may be defined.

In some examples of the wireless communication system100, the radio heads105-cand/or UEs115may include multiple antennas for employing antenna diversity schemes to improve communication quality and reliability between radio heads105-cand UEs115. Additionally or alternatively, radio heads105-cand/or UEs115may employ multiple-input, multiple-output (MIMO) techniques that may take advantage of multi-path environments to transmit multiple spatial layers carrying the same or different coded data.

FIG. 2illustrates an example of a wireless communications system200for heterogeneous WOLA windowing or heterogeneous filtering for OFDM and/or SC-FDMA waveforms, in accordance with aspects of the present disclosure. Wireless communications system200may include a UE215, which may be examples of a UE115ofFIG. 1, and base station205, which may be an example of one or more of the radio heads105-c, eNBs105-a, or ANCs105-bdescribed with reference toFIG. 1. UE215and base station205may communicate using one or several carriers225(including one or more eCCs). In some examples, symbols may be processed by signal processing components210and may be transmitted/received by transmission/receive components220.

In some examples, the signal processing components210-aof base station205may divide a symbol into two or more subsets of tones and process the different subsets using one or more different processing parameters, such as different types of WOLA weighting windows, which may include different weights and WOLA weighting lengths. In some examples, the different processing parameters may include different bandpass filtering lengths. In examples that use WOLA techniques for OOB suppression, subsets of tones associated with a head portion or a tail portion (e.g., edge tones) of a symbol may be processed with a relatively long WOLA weighting length, and a subset of tones associated with a center portion of the symbol may be processed with a relatively short WOLA weighting length. The processing components may process the different subsets of tones separately, and the different subsets of tones of the symbol may be overlapped to form a transmission waveform for the symbol, which may be overlapped and added with adjacent symbol transmission waveforms and transmitted using transmission/receive components220-a. When receiving a waveform, the processing components may perform similar processes and apply the different types of WOLA weighting windows to extract the different subsets of tones.

In examples that use transmission filtering using a bandpass filter for OOB suppression, signal processing components210-aof base station205may divide tones of a symbol into subsets of tones associated with a head portion or a tail portion of the symbol and may process these subsets of tones with a relatively long filter length (e.g., a relatively large number of samples or taps at a finite impulse response (FIR) filter). The signal processing components210-aalso may divide the tones of the symbol into a subset of tones associated with a center portion of the symbol, and may process these tones with a relatively short filter length. Such heterogeneous processing of tones within a symbol may provide enhanced spectral shape for OOB suppression at transmission edges, and also provide reduced ISI for the center tones of the symbol. The different portions of the symbol may be overlapped to form a transmission waveform for the symbol, and transmitted using transmission/receive components220-a. In some examples a CP may be added to the symbol transmission, and the signal processing components210-amay process the transmission waveform for the symbol to be overlapped and added with adjacent symbol transmission waveforms. In certain examples, such a CP may simply be replaced by a guard interval, and the different portions of the symbol may be added to form the symbol transmission waveform which may simply be concatenated with other symbol transmission waveforms and transmitted using transmission/receive components220-a. When receiving a waveform, the processing components may perform similar processes and apply the different types of filtering windows to extract the different subsets of tones.

While the above examples were discussed with respect to signal processing components210-aand transmission/receive components220-aof base station205, such techniques may also be employed by signal processing components210-band transmission/receive components220-bof UE215. Furthermore, in some examples UE215may transmit uplink transmissions using SC-FDMA (or other multiple access technologies), and the WOLA weighting or bandpass filtering techniques described herein may be applied to such uplink symbols that are transmitted from UE215.

FIG. 3illustrates an example of heterogeneous WOLA processing of a symbol300in accordance with aspects of the present disclosure. In some cases, example of heterogeneous WOLA processing of a symbol300may represent aspects of techniques performed by a UE, base station, radio head, eNB, or ANC as described with reference toFIGS. 1-2.

In the example ofFIG. 3, a symbol305may have a number of frequency tones in the frequency domain. The tones of symbol305may be divided up into a first subset of tones310corresponding to center tones of the symbol, a second subset of tones corresponding to head tones315of the symbol, and a third subset of tones corresponding to tail tones320of the symbol. Each of the subsets of tones310-320may be WOLA processed separately. In this example, the first subset of center tones310may be processed with a first WOLA weighting procedure325with a weighting length L1. The second subset of head tones315may be processed with a second WOLA weighting procedure330with a weighting length L2. Similarly, the third subset of tail tones320may be processed with a third WOLA weighting procedure335with a weighting length L3. In some examples, the side bands corresponding to head tones315and tail tones320may be processed with a relatively long WOLA weighting length to help reduce the ICI effect and improve OOB suppression. Further, the center band corresponding to center tones310may be processed with a relatively short WOLA weighting length to reduce the ISI effect. In some examples, the different subsets of tones310-320, or sub-symbols, may be aligned and added340, and may then be overlapped and added with adjacent symbols.

While three subsets tones310-320are illustrated inFIG. 3, other examples may include only two subsets of tones, such as for tones corresponding to head tones315and center tones310. As indicated above, in some examples, the weighting length L2and the weighting length L3may be the same length, and be longer than weighting length L1. In other examples, L2and L3may be different, and selected based on a particular type of symbol that is adjacent to the symbol305(e.g., a symbol of a same service or different service than symbol305). In some examples, L2and L3may correspond to approximately 5% of the length of symbol305, and the length L1may correspond to approximately 1% to 2% of the length of symbol305. Of course, these values are examples for the purposes of illustration and discussion only, and other values for the different weighting lengths may be based and may be selected based on particular applications, network operating conditions, traffic being transmitted, and the like.

FIG. 4Aillustrates an example of transmit processing chains400for heterogeneous WOLA windowing and filtering for OFDM waveforms. In some cases, processing chains400may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, various examples may divide tones of an OFDM symbols into two or more subsets of tones, and each subset of tones may be processed separately for WOLA weighting. In the example ofFIG. 4A, head tones405may include a subset of tones at the head, or beginning, of an OFDM symbol. The head tones405may be provided to IFFT410that may generate a number of samples corresponding to head tones405, which may be provided to a parallel to serial conversion415function to generate a series of time samples corresponding to head tones405. A CP and extension with length L2may be added to the time samples at420, and a weighting function425performed with a weighting length L2that corresponds to extension length L2.

Similarly, center tones430may include a subset of tones around the center of the OFDM symbol. The center tones430may be provided to IFFT435that may generate a number of samples corresponding to center tones430, which may be provided to a parallel to serial conversion440function to generate a series of time samples corresponding to center tones430. A CP and extension with length L1may be added to the time samples at445, and a weighting function450performed with a weighting length L1that corresponds to extension length L1.

Likewise, tail tones455may include a subset of tones at the tail, or end, of the OFDM symbol. The tail tones455may be provided to IFFT460that may generate a number of samples corresponding to tail tones455, which may be provided to a parallel to serial conversion465function to generate a series of time samples corresponding to tail tones455. A CP and extension with length L3may be added to the time samples at470, and a weighting function475performed with a weighting length L3that corresponds to extension length L3.

Each of the weighted sub-symbols may be provided to alignment and sub-symbol addition function480that may assemble the weighted sub-symbols to provide a transmission waveform for the OFDM symbol. The transmission waveform may be provided to overlap and add function485to provide an overlapped and added waveform with adjacent symbols, that may then be transmitted by a transmitter.

As discussed above, in some examples the weighting length L1may be selected to be shorter than the weighting length L2, which may provide reduced ISI effects at the center tones430, and reduced ICI effects and improved OOB suppression for head tones405and tail tones455. In some examples, the lengths L2and L3may be the same length, in which case the processing for both the head tones405and the tail tones455may be performed in the same processing chain.

FIG. 4Billustrates an example of receive processing chains4000for heterogeneous WOLA windowing and filtering for OFDM waveforms. In some cases, processing chains4000may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, various examples may divide tones of an OFDM symbols into two or more subsets of tones, and each subset of tones may be processed separately for WOLA weighting. In the example ofFIG. 4B, a receiver may receive an OFDM symbol waveform, and may truncate the received waveform for the OFDM symbol at4005. Processing for head tones4025include weighting the received waveform at a weighting function4010performed with a weighting length L2that corresponds to extension length L2. The weighted samples may be provided to a serial to parallel conversion4015function, and provided to fast Fourier transform (FFT)4020, that may output the head tones4025.

Similarly, center tones4045may include a subset of tones around the center of the OFDM symbol. The center tones4045processing may include weighting the received waveform at a weighting function4030performed with a weighting length L1that corresponds to extension length L1. The weighted samples may be provided to a serial to parallel conversion4035function, and provided to FFT4040, that may output the center tones4045.

Likewise, tail tones4065may include a subset of tones at the tail, or end, of the OFDM symbol. The tail tones4065processing may include weighting the received waveform at a weighting function4050performed with a weighting length L3that corresponds to extension length L3. The weighted samples may be provided to a serial to parallel conversion4055function, and provided to FFT4060, that may output the tail tones4065.

As discussed above, in some examples the weighting length L1may be selected to be shorter than the weighting length L2, which may provide reduced ISI effects at the center tones430, and reduced ICI effects and improved OOB suppression for head tones405and tail tones455.

FIG. 5Aillustrates an example of transmit sub-symbol processing and symbol overlapping500for heterogeneous WOLA windowing for OFDM waveforms. In some cases, sub-symbol processing and symbol overlapping500may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

In the example ofFIG. 5A, head sub-symbol505may be weighted using a WOLA weighting length L2, as discussed above with respect toFIG. 4. In this example, an extension length L2may be added as L2/2520before a CP525and after IFFT output530for head tones. Similarly, center sub-symbol510may be weighted using a WOLA weighting length L1, as discussed above with respect toFIG. 4. In this example, an extension length L1may be added as L1/2535before CP540and after IFFT output545for center tones. Finally, tail sub-symbol515may be weighted using a WOLA weighting length L3, as discussed above with respect toFIG. 4. In this example, an extension length L3may be added as L3/2550before CP555and after IFFT output560for tail tones.

Each of the sub-symbol505-515waveforms may be combined at combiner565, which may align and add the sub-symbols505-515to provide a symbol waveform such as waveform570for symbol 1. The waveform from combiner565may be overlapped and added with an adjacent waveform575for symbol 2, in this example, with the resultant overlapped and added waveform transmitted to a receiver. The amount of overlap580for waveform570and waveform575may correspond to Max(L1, L2, L3).

FIG. 5Billustrates an example of receive sub-symbol processing and symbol overlapping5000for heterogeneous WOLA windowing for OFDM waveforms. In some cases, sub-symbol processing and symbol overlapping5000may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

In the example ofFIG. 5B, a received waveform may be processed differently for each subset of tones. More specifically, if three subsets of tones are transmitted, receive processing for each of the subsets may be performed based on the transmission parameters for each subset. For example, a head sub-symbol and a tail sub-symbol may be weighted using a first type of WOLA weighting window, and a center sub-symbol may be weighted using a second type of WOLA weighting window. In each case, the received waveform5005, which may include a CP5015and a received waveform for an OFDM symbol5020, may be processed with a WOLA weighting window5025, that may have a weighting length L associated with the particular subset of tones. The weightings for the weighting windows L may be overlapped and added to obtain a weighted waveform5035, which may then be provided to a FFT input5040to generate the associated sub-symbol or subset of tones.

FIG. 6illustrates an example of heterogeneous transmission filtering600of an OFDM symbol. In some cases, heterogeneous transmission filtering600may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

In the example ofFIG. 6, an OFDM symbol605may have a number of frequency tones in the frequency domain. The tones of OFDM symbol605may be divided up into a first subset of tones610corresponding to center tones of the OFDM symbol, a second subset of tones corresponding to head tones615of the OFDM symbol, and a third subset of tones corresponding to tail tones620of the OFDM symbol. Each of the subsets of tones610-620may be filtered separately. In this example, the first subset of center tones610may be filtered with a first filtering procedure625with a filter length L1. The second subset of head tones615may be filtered with a second filtering procedure630with a filter length L2. Similarly, the third subset of tail tones620may be filtered with a third filtering procedure635with a filter length L3. In some examples, the side bands corresponding to head tones615and tail tones620may be processed with a relatively long filter lengths to help reduce the ICI effect and improve OOB suppression. Further, the center band corresponding to center tones610may be processed with a relatively short filter length to reduce the ISI effect. In some examples, the different subsets of tones610-620, or sub-symbols, may be aligned and added640, and may then be overlapped and added with adjacent symbols.

While three subsets tones610-620are illustrated inFIG. 6, other examples may include only two subsets of tones, such as for tones corresponding to head tones615and center tones610. As indicated above, in some examples, the filter length L2and the filter length L3may be the same length, and be longer than filter length L1. In other examples, L2and L3may be different, and selected based on a particular type of symbol that is adjacent to the symbol605(e.g., a symbol of a same service or different service than symbol605). In some examples, L2and L3may correspond to approximately 5% of the length of symbol605, and the length L1may correspond to approximately 1% to 2% of the length of symbol605. Of course, these values are examples for the purposes of illustration and discussion only, and other values for the different weighting lengths may be based and may be selected based on particular applications, network operating conditions, traffic being transmitted, and the like.

FIG. 7Aillustrates an example of transmit processing chains700for heterogeneous transmission filtering for OFDM waveforms. In some cases, processing chains700may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, various examples may divide tones of an OFDM symbols into two or more subsets of tones, and in some examples each subset of tones may be filtered separately. In the example ofFIG. 7, head tones705may include a subset of tones at the head, or beginning, of an OFDM symbol. The head tones705may be provided to IFFT710that may generate a number of samples corresponding to head tones705, which may be provided to a parallel to serial conversion715function to generate a series of time samples corresponding to head tones705. A CP may be added to the time samples at720, and the CP and time samples may be filtered with a filter length L2at bandpass filter725.

Similarly, center tones730may include a subset of tones around the center of the OFDM symbol. The center tones730may be provided to IFFT735that may generate a number of samples corresponding to center tones730, which may be provided to a parallel to serial conversion740function to generate a series of time samples corresponding to center tones730. A CP may be added to the time samples at745, and the CP and time samples may be filtered with a filter length L1at bandpass filter750.

Likewise, tail tones755may include a subset of tones at the tail, or end, of the OFDM symbol. The tail tones755may be provided to IFFT760that may generate a number of samples corresponding to tail tones755, which may be provided to a parallel to serial conversion765function to generate a series of time samples corresponding to tail tones755. A CP may be added to the time samples at770, and the CP and time samples may be filtered with a filter length L3at bandpass filter725.

Each of the filtered sub-symbols may be provided to alignment and sub-symbol addition function780that may assemble the filtered sub-symbols to provide a transmission waveform for the OFDM symbol. The transmission waveform may be provided to overlap and add function785to provide an overlapped and added waveform with adjacent symbols, that may then be transmitted by a transmitter.

As discussed above, in some examples the filter length L1may be selected to be shorter than the filter length L2, which may provide reduced ISI effects at the center tones730, and reduced ICI effects and improved OOB suppression for head tones705and tail tones755. In some examples, the lengths L1and L2may be the same length, in which case the processing for both the head tones705and the tail tones755may be performed in the same processing chain.

FIG. 7Billustrates an example of receive processing chains7000for heterogeneous transmission filtering for OFDM waveforms. In some cases, processing chains700may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, various examples may divide tones of an OFDM symbols into two or more subsets of tones, and in some examples each subset of tones may be filtered separately. In the example ofFIG. 7B, head tones7030may include a subset of tones at the head, or beginning, of an OFDM symbol. In the example ofFIG. 7B, a receiver may receive an OFDM symbol waveform at7005. Processing for head tones7030include bandpass filtering the received waveform at a filtering function7010performed with a filter length L2. The filtered samples may be truncated to a size corresponding to the transmit FFT size at truncation function7015, with the truncated waveform provided to a serial to parallel conversion7020function, and provided to FFT7025, that may output the head tones7030.

Similarly, center tones7055may include a subset of tones around the center of the OFDM symbol. The center tones7055processing may include bandpass filtering the received waveform at a filtering function7035performed with a filter length L1. The filtered samples may be truncated to a size corresponding to the transmit FFT size at truncation function7040, with the truncated waveform provided to a serial to parallel conversion7045function, and provided to FFT7050, that may output the center tones7055.

Likewise, tail tones7080may include a subset of tones at the tail, or end, of the OFDM symbol. The tail tones7080processing may include bandpass filtering the received waveform at a filtering function7060performed with a filter length L3. The filtered samples may be truncated to a size corresponding to the transmit FFT size at truncation function7065, with the truncated waveform provided to a serial to parallel conversion7070function, and provided to FFT7075, that may output the tail tones7080.

As discussed above, in some examples the filter length L1may be selected to be shorter than the filter length L2, which may provide reduced ISI effects at the center tones7055, and reduced ICI effects and improved OOB suppression for head tones7030and tail tones7080.

FIG. 8illustrates an example of sub-symbol processing and symbol overlapping800for heterogeneous transmission filtering for OFDM waveforms. In some cases, sub-symbol processing and symbol overlapping800may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

In the example ofFIG. 8, head sub-symbol805may be filtered using a filter length L2, as discussed above with respect toFIG. 7. In this example, filtering may begin at (L2−1)/2 before a CP825and end at (L2−1)/2 after IFFT output830for head tones. Similarly, center sub-symbol810may be filtered using a filter length L1, as discussed above with respect toFIG. 4. In this example, filtering may begin at (L1−1)/2 before a CP840and end at (L1−1)/2 after IFFT output845for center tones. Finally, tail sub-symbol815may be filtered using a filter length L3, as discussed above with respect toFIG. 7. In this example, filtering may begin at (L3−1)/2 before a CP855and end at (L3−1)/2 after IFFT output860for tail tones.

Each of the sub-symbol805-815waveforms may be combined at combiner865, which may align and add the sub-symbols805-815to provide a symbol waveform such as waveform870for symbol 1. The waveform from combiner865may be overlapped and added with an adjacent waveform875for symbol 2, in this example, with the resultant overlapped and added waveform transmitted to a receiver. The amount of overlap880for waveform870and waveform875may correspond to (Max(L1, L2, L3)−1).

FIG. 9Aillustrates an example of transmit processing chains900for heterogeneous transmission filtering for OFDM waveforms with guard intervals. In some cases, processing chains900may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, again various examples may divide tones of an OFDM symbols into two or more subsets of tones, and in some examples each subset of tones may be filtered separately. In the example ofFIG. 9A, head tones905may include a subset of tones at the head, or beginning, of an OFDM symbol. The head tones905may be provided to IFFT910that may generate a number of samples corresponding to head tones905, which may be provided to a parallel to serial conversion915function to generate a series of time samples corresponding to head tones905. A guard interval may be added to the time samples at920, and guard interval and time samples may be filtered with a filter length L2at bandpass filter925. In some examples, the guard interval may be a zero power guard interval where no power is used in the transmissions for the period of the guard interval.

Similarly, center tones930may include a subset of tones around the center of the OFDM symbol. The center tones930may be provided to IFFT935that may generate a number of samples corresponding to center tones930, which may be provided to a parallel to serial conversion940function to generate a series of time samples corresponding to center tones930. A guard interval may be added to the time samples at945, and the guard interval and time samples may be filtered with a filter length L1at bandpass filter950.

Likewise, tail tones955may include a subset of tones at the tail, or end, of the OFDM symbol. The tail tones955may be provided to IFFT960that may generate a number of samples corresponding to tail tones955, which may be provided to a parallel to serial conversion965function to generate a series of time samples corresponding to tail tones955. A guard interval may be added to the time samples at970, and the guard interval and time samples may be filtered with a filter length L3at bandpass filter925.

Each of the filtered sub-symbols may be provided to alignment and sub-symbol addition function980that may assemble the filtered sub-symbols to provide a transmission waveform for the OFDM symbol. The transmission waveform may be concatenated at985with adjacent symbols and may be transmitted by a transmitter.

As discussed above, in some examples the filter length L1may be selected to be shorter than the filter length L2, which may provide reduced ISI effects at the center tones930, and reduced ICI effects and improved OOB suppression for head tones905and tail tones955.

FIG. 9Billustrates an example of receive processing chains9000for heterogeneous transmission filtering for OFDM waveforms with guard intervals. In some cases, processing chains9000may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, again various examples may divide tones of an OFDM symbols into two or more subsets of tones, and in some examples each subset of tones may be filtered separately. In the example ofFIG. 9B, head tones9030may include a subset of tones at the head, or beginning, of an OFDM symbol. A receiver may receive an OFDM symbol waveform at9005. Processing for head tones9030include bandpass filtering the received waveform at a filtering function9010performed with a filter length L2. The filtered samples may be truncated to a size corresponding to the transmit FFT size plus a guard interval length at truncation function9015, with the truncated waveform provided to a zero-padding function9017to zero pad the waveform to the transmit IFFT size. The padded output is provided to serial to parallel conversion9020function, and provided to a 2-times size FFT9025. The FFT output may be downsampled by two at downsampling function9027, that may output the head tones9030.

Similarly, center tones9055may include a subset of tones around the center of the OFDM symbol. The center tones9055processing may include bandpass filtering the received waveform at a filtering function9035performed with a filter length L1. The filtered samples may be truncated to a size corresponding to the transmit FFT size plus a guard interval length at truncation function9040, with the truncated waveform provided to a zero-padding function9042to zero pad the waveform to the transmit IFFT size. The padded output is provided to serial to parallel conversion9045function, and provided to a 2-times size FFT9050. The FFT output may be downsampled by two at downsampling function9052, that may output the center tones9055.

Likewise, tail tones9080may include a subset of tones at the tail, or end, of the OFDM symbol. The tail tones9080processing may bandpass filtering the received waveform at a filtering function9060performed with a filter length L3. The filtered samples may be truncated to a size corresponding to the transmit FFT size plus a guard interval length at truncation function9065, with the truncated waveform provided to a zero-padding function9067to zero pad the waveform to the transmit IFFT size. The padded output is provided to serial to parallel conversion9070function, and provided to a 2-times size FFT9075. The FFT output may be downsampled by two at downsampling function9077, that may output the tail tones9080.

As discussed above, in some examples the filter length L1may be selected to be shorter than the filter length L2, which may provide reduced ISI effects at the center tones9055, and reduced ICI effects and improved OOB suppression for head tones9030and tail tones9080.

FIG. 10illustrates an example of sub-symbol processing and symbol overlapping1000for heterogeneous transmission filtering for OFDM waveforms with guard intervals. In some cases, sub-symbol processing and symbol overlapping1000may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

In the example ofFIG. 10, head sub-symbol1005may be filtered using a filter length L2, as discussed above with respect toFIG. 9. In this example, filtering may begin at the beginning of IFFT output1030and end during guard interval1025. Similarly, center sub-symbol1010may be filtered using a filter length L1, as discussed above with respect toFIG. 9. In this example, filtering may begin at the beginning of IFFT output1045and end at the end of guard interval1040. Finally, tail sub-symbol1015may be filtered using a filter length L3, as discussed above with respect toFIG. 9. In this example, filtering may begin at the beginning of IFFT output1060and end during guard interval1055.

Each of the subsymbol1005-1015waveforms may be combined at combiner1065, which may align and add the sub-symbols1005-1015to provide a symbol waveform such as waveform1070for symbol 1. The waveform from combiner1065may be provided, and a subsequent waveform1075for a subsequent symbol may be concatenated with the waveform1070and transmitted to a receiver.

FIG. 11shows a block diagram1100of a device1105that supports heterogeneous weighted overlap-add windowing and filtering for OFDM and/or SC-FDMA waveforms in accordance with various aspects of the present disclosure. Device1105may be an example of aspects of a UE or base station as described with reference toFIGS. 1 and 2. Device1105may include receiver1110, Communication manager1115, and transmitter1120. Device1105may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver1110may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to heterogeneous weighted overlap-add windowing and filtering for OFDM waveforms, etc.). Information may be passed on to other components of the device. The receiver1110may be an example of aspects of the transceiver1440described with reference toFIG. 14or transceiver1540described with reference toFIG. 15.

Communication manager1115may be an example of aspects of the UE Communication manager1415described with reference toFIG. 14or the base station Symbol communication manager1515described with reference toFIG. 15. Communication manager1115may identify a set of tones of a first symbol, a first subset of the set of tones, and a second subset of the set of tones, apply a first weighting length to the first subset of the set of tones and a second weighting length to the second subset of the set of tones in a WOLA procedure, the second weighting length being longer than the first weighting length, and obtain a first transmission waveform for the first symbol based on the applying.

Communication manager1115may also identify a set of tones of a first symbol, a first subset of the set of tones, and a second subset of the set of tones, apply a first filter length to the first subset of the set of tones and a second filter length to the second subset of the set of tones in a bandpass filtering procedure, the second filter length being longer than the first filter length, and obtain a first transmission waveform for the first symbol based on the applying.

Transmitter1120may transmit signals generated by other components of the device. In some examples, the transmitter1120may be collocated with a receiver1110in a transceiver module. For example, the transmitter1120may be an example of aspects of the transceiver1440described with reference toFIG. 14or the transceiver1540described with reference toFIG. 15. The transmitter1120may include a single antenna, or it may include a set of antennas.

In some example, transmitter1120may transmit the first transmission waveform, transmit the overlapped and added first transmission waveform and second transmission waveform, transmit the first transmission waveform, transmit the overlapped and added first transmission waveform and second transmission waveform, and transmit the concatenated first transmission waveform and second transmission waveform.

FIG. 12shows a block diagram1200of a device1205that supports heterogeneous weighted overlap-add windowing and filtering for waveforms in accordance with various aspects of the present disclosure. Device1205may be an example of aspects of a device1105or a UE or base station as described with reference toFIGS. 1, 2 and 11. Device1205may include receiver1210, communication manager1215, and transmitter1220. Device1205may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver1210may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to heterogeneous weighted overlap-add windowing and filtering for OFDM and/or SC-FDMA waveforms, etc.). Information may be passed on to other components of the device. The receiver1210may be an example of aspects of the transceiver1440described with reference toFIG. 14or the transceiver1540described with reference toFIG. 15.

Communication manager1215may be an example of aspects of the UE communication manager1415described with reference toFIG. 14or the base station symbol communication manager1515described with reference toFIG. 15. Communication manager1215may also include tone identifying component1225, weighting component1230, waveform generation component1235, and filter component1240.

Tone identifying component1225may identify a set of tones of a first symbol, a first subset of the set of tones, and a second subset of the set of tones, identify a third subset of the set of tones including a tail portion of the set of tones, and where the applying further includes applying a third weighting length to the third subset of the set of tones in the WOLA procedure to obtain the first transmission waveform. In examples that utilize transmission filtering, tone identifying component1225may identify a third subset of the set of tones including a tail portion of the set of tones, where the applying further includes applying a third filter length to the third subset of the set of tones in the bandpass filtering procedure to obtain the first transmission waveform. In some cases, the first subset of the set of tones includes a center portion of the set of tones and the second subset of the set of tones includes a head portion of the set of tones.

Weighting component1230may apply a first weighting length to the first subset of the set of tones and a second weighting length to the second subset of the set of tones in a WOLA procedure, the second weighting length being longer than the first weighting length. In some examples, weighting component1230may select the first weighting length for a first weighting procedure to be performed on the first subset of the set of tones and select the second weighting length for a second weighting procedure to be performed on the second subset of the set of tones, perform the first weighting procedure on the first subset of the set of tones to obtain a weighted first subset of samples corresponding to the first subset of the set of tones, and perform the second weighting procedure on the second subset of the set of tones to obtain a weighted second subset of samples corresponding to the second subset of the set of tones. In some cases, a third weighting procedure may be performed with a third weighting length. The second and third weighting lengths may be longer than the first weighting length.

Waveform generation component1235may obtain a first transmission waveform for the first symbol based on the overlapping and adding the weighted first subset of samples and the weighted second subset of samples to obtain the first transmission waveform, and overlap and add the first transmission waveform and a second transmission waveform. In some cases, an amount of overlapping of the first transmission waveform and the second transmission waveform is determined based on a longest length of the first weighting length or the second weighting length.

Filter component1240may apply a first filter length to the first subset of the set of tones and a second filter length to the second subset of the set of tones in a bandpass filtering procedure, the second filter length being longer than the first filter length, perform the first bandpass filtering procedure on the first subset of the set of tones to obtain a filtered first subset of samples corresponding to the first subset of the set of tones and perform the second bandpass filtering procedure on the second subset of the set of tones to obtain a filtered second subset of samples corresponding to the second subset of the set of tones. Filter component1240may also bandpass filter a CP added to each subset of tones. In some examples, a CP may not be added to the set of tones, and the filter component1240may bandpass filter a guard interval and a subset of time domain samples corresponding to a subset of tones.

Transmitter1220may transmit signals generated by other components of the device. In some examples, the transmitter1220may be collocated with a receiver1210in a transceiver module. For example, the transmitter1220may be an example of aspects of the transceiver1440described with reference toFIG. 14or the transceiver1540described with reference toFIG. 15. The transmitter1220may include a single antenna, or it may include a set of antennas.

FIG. 13shows a block diagram1300of a communication manager1315that supports heterogeneous weighted overlap-add windowing and filtering for OFDM and/or SC-FDMA waveforms in accordance with various aspects of the present disclosure. The communication manager1315may be an example of aspects of an Communication manager1115, a communication manager1215, a UE communication manager1415, or a base station symbol communication manager1515described with reference toFIGS. 11, 12, 14, and 15. The communication manager1315may include tone identifying component1325, weighting component1330, waveform generation component1335, and filter component1340. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

Tone identifying component1325may identify a set of tones of a first symbol, a first subset of the set of tones, and a second subset of the set of tones, identify a third subset of the set of tones including a tail portion of the set of tones. Weighting component1330may apply a first weighting length to the first subset of the set of tones and a second weighting length to the second subset of the set of tones in a WOLA procedure, the second weighting length being longer than the first weighting length. In some examples, weighting component1330may select the first weighting length for a first weighting procedure to be performed on the first subset of the set of tones and select the second weighting length for a second weighting procedure to be performed on the second subset of the set of tones.

Waveform generation component1335may obtain a first transmission waveform for the first symbol based on the weighted first subset of samples and the weighted second subset of samples to obtain the first transmission waveform, and may overlap and add the first transmission waveform and a second transmission waveform. In some cases, an amount of overlapping of the first transmission waveform and the second transmission waveform is determined based on a longest length of the first weighting length or the second weighting length.

Filter component1340may apply a first filter length to the first subset of the set of tones and a second filter length to the second subset of the set of tones in a bandpass filtering procedure, the second filter length being longer than the first filter length. The filter component1340also may perform the first bandpass filtering procedure on the first subset of the set of tones to obtain a filtered first subset of samples corresponding to the first subset of the set of tones and perform the second bandpass filtering procedure on the second subset of the set of tones to obtain a filtered second subset of samples corresponding to the second subset of the set of tones. In some examples, filter component1340may bandpass filter a CP or a guard interval added to time domain samples that correspond to a subset of tones based on a selected filter length associated with the subset of tones.

Cyclic prefix component1345may add a cyclic prefix to a set of time domain samples. In some cases, cyclic prefix component1345may add both a cyclic prefix and an extension length to each subset of time domain samples corresponding to the first or second subset of the set of tones, the extension length corresponding to a weighting length of the corresponding subset of tones. Process repetition component1350may repeat the identifying and the applying for a second set of tones of a second symbol to obtain a second transmission waveform for the second symbol.

Filter selection component1355may select the first filter length for a first bandpass filtering procedure to be performed on the first subset of the set of tones and select the second filter length for a second bandpass filtering procedure to be performed on the second subset of the set of tones. Guard interval component1360may add a guard interval to a subset of time domain samples, and concatenation component1365may concatenate the first transmission waveform and the second transmission waveform.

FIG. 14shows a diagram of a system1400including a device1405that supports heterogeneous weighted overlap-add windowing and filtering for OFDM and/or SC-FDMA waveforms in accordance with various aspects of the present disclosure. Device1405may be an example of a device1105, device1205, or a UE as described above, e.g., with reference toFIGS. 1, 2, 11, and 12.

Device1405may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including UE communication manager1415, processor1425, memory1430, software1435, transceiver1440, and antenna1445. These components may be in electronic communication via one or more busses (e.g., bus1410).

Processor1425may include an intelligent hardware device, (e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc.) Memory1430may include random access memory (RAM) and read only memory (ROM). The memory1430may store computer-readable, computer-executable software1435including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory1430can contain, among other things, a Basic Input-Output system (BIOS) which may control basic hardware and/or software operation such as the interaction with peripheral components or devices.

Software1435may include code to implement aspects of the present disclosure, including code to support heterogeneous weighted overlap-add windowing and filtering for OFDM and/or SC-FDMA waveforms. Software1435can be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software1435may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

In some cases, the wireless device may include a single antenna1445. However, in some cases the device may have more than one antenna1445, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

FIG. 15shows a diagram of a system1500including a device1505that supports heterogeneous weighted overlap-add windowing and filtering for OFDM and/or SC-FDMA waveforms in accordance with various aspects of the present disclosure. Device1505may be an example of a device1105, a device1205, or a base station as described above, e.g., with reference toFIGS. 1, 2, 11, 12 and 13.

Device1505may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including base station symbol communication manager1515, processor1525, memory1530, software1535, transceiver1540, antenna1545, network communications manager1550, and base station communications manager1555. These components may be in electronic communication via one or more busses (e.g., bus1510).

Processor1525may include an intelligent hardware device, (e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc.) Memory1530may include random access memory (RAM) and read only memory (ROM). The memory1530may store computer-readable, computer-executable software1535including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory1530can contain, among other things, a Basic Input-Output system (BIOS) which may control basic hardware and/or software operation such as the interaction with peripheral components or devices.

Software1535may include code to implement aspects of the present disclosure, including code to support heterogeneous weighted overlap-add windowing and filtering for OFDM and/or SC-FDMA waveforms. Software1535can be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software1535may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

Network communications manager1550may manage communications with the core network (e.g., via one or more wired backhaul links). For example, the network communications manager1550may manage the transfer of data communications for client devices, such as one or more UEs115.

FIG. 16shows a flowchart illustrating a method1600for heterogeneous weighted overlap-add windowing for OFDM and/or SC-FDMA waveforms in accordance with various aspects of the present disclosure. The operations of method1600may be implemented by a UE or base station or its components as described herein. For example, the operations of method1600may be performed by a communication manager as described with reference toFIGS. 11 through 13. In some examples, a UE or base station may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE or base station may perform aspects the functions described below using special-purpose hardware.

At block1605, the UE or base station may identify a set of tones of a first symbol, a first subset of the set of tones, and a second subset of the set of tones. The operations of block1605may be performed according to the methods described with reference toFIGS. 2 through 5. In certain examples, aspects of the operations of block1605may be performed by a tone identifying component as described with reference toFIGS. 11 through 13.

At block1610, the UE or base station may apply a first weighting length to the first subset of the set of tones and a second weighting length to the second subset of the set of tones in a WOLA procedure, the second weighting length being longer than the first weighting length. The operations of block1610may be performed according to the methods described with reference toFIGS. 2 through 5. In certain examples, aspects of the operations of block1610may be performed by a weighting component as described with reference toFIGS. 11 through 13.

At block1615, the UE or base station may obtain a first transmission waveform for the first symbol based on the applying. The operations of block1615may be performed according to the methods described with reference toFIGS. 2 through 5. In certain examples, aspects of the operations of block1615may be performed by a waveform generation component as described with reference toFIGS. 11 through 13.

At block1620, the UE or base station may transmit the first transmission waveform. The operations of block1620may be performed according to the methods described with reference toFIGS. 2 through 5. In certain examples, aspects of the operations of block1620may be performed by a transmitter as described with reference toFIGS. 11 through 13.

FIG. 17shows a flowchart illustrating a method1700for heterogeneous weighted overlap-add windowing for OFDM and/or SC-FDMA waveforms in accordance with various aspects of the present disclosure. The operations of method1700may be implemented by a UE or base station or its components as described herein. For example, the operations of method1700may be performed by a communication manager as described with reference toFIGS. 11 through 13. In some examples, a UE or base station may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE or base station may perform aspects the functions described below using special-purpose hardware.

At block1705, the UE or base station may identify a set of tones of a first symbol, a first subset of the set of tones, and a second subset of the set of tones. The operations of block1705may be performed according to the methods described with reference toFIG. 2 through 5. In certain examples, aspects of the operations of block1705may be performed by a tone identifying component as described with reference toFIGS. 11 through 13.

At block1710, the UE or base station may select the first weighting length for a first weighting procedure to be performed on the first subset of the set of tones and select the second weighting length for a second weighting procedure to be performed on the second subset of the set of tones. The operations of block1710may be performed according to the methods described with reference toFIGS. 2 through 5. In certain examples, aspects of the operations of block1710may be performed by a weighting component as described with reference toFIGS. 11 through 13.

At block1715, the UE or base station may perform the first weighting procedure on the first subset of the set of tones to obtain a weighted first subset of samples corresponding to the first subset of the set of tones and perform the second weighting procedure on the second subset of the set of tones to obtain a weighted second subset of samples corresponding to the second subset of the set of tones. The operations of block1715may be performed according to the methods described with reference toFIGS. 2 through 5. In certain examples, aspects of the operations of block1715may be performed by a weighting component as described with reference toFIGS. 11 through 13.

At block1720, the UE or base station may overlap and add the weighted first subset of samples and the weighted second subset of samples to obtain the first transmission waveform. The operations of block1720may be performed according to the methods described with reference toFIGS. 2 through 5. In certain examples, aspects of the operations of block1720may be performed by a waveform generation component as described with reference toFIGS. 11 through 13.

At block1725, the UE or base station may transmit the first transmission waveform. The operations of block1725may be performed according to the methods described with reference toFIG. 2 through 5. In certain examples, aspects of the operations of block1725may be performed by a transmitter as described with reference toFIGS. 11 through 13.

FIG. 18shows a flowchart illustrating a method1800for heterogeneous filtering for waveforms in accordance with various aspects of the present disclosure. The operations of method1800may be implemented by a UE or base station or its components as described herein. For example, the operations of method1800may be performed by a communication manager as described with reference toFIGS. 11 through 13. In some examples, a UE or base station may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE or base station may perform aspects the functions described below using special-purpose hardware.

At block1805, the UE or base station may identify a set of tones of a first symbol, a first subset of the set of tones, and a second subset of the set of tones. The operations of block1805may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block1805may be performed by a tone identifying component as described with reference toFIGS. 11 through 13.

At block1810, the UE or base station may apply a first filter length to the first subset of the set of tones and a second filter length to the second subset of the set of tones in a bandpass filtering procedure, the second filter length being longer than the first filter length. The operations of block1810may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block1810may be performed by a filter component as described with reference toFIGS. 11 through 13.

At block1815, the UE or base station may obtain a first transmission waveform for the first symbol based on the applying. The operations of block1815may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block1815may be performed by a waveform generation component as described with reference toFIGS. 11 through 13.

At block1820, the UE or base station may transmit the first transmission waveform. The operations of block1820may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block1820may be performed by a transmitter as described with reference toFIGS. 11 through 13.

FIG. 19shows a flowchart illustrating a method1900for heterogeneous filtering for OFDM and/or SC-FDMA waveforms in accordance with various aspects of the present disclosure. The operations of method1900may be implemented by a UE or base station or its components as described herein. For example, the operations of method1900may be performed by a communication manager as described with reference toFIGS. 11 through 13. In some examples, a UE or base station may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE or base station may perform aspects the functions described below using special-purpose hardware.

At block1905, the UE or base station may identify a set of tones of a first symbol, a first subset of the set of tones, and a second subset of the set of tones. The operations of block1905may be performed according to the methods described with reference toFIG. 6 through 10. In certain examples, aspects of the operations of block1905may be performed by a tone identifying component as described with reference toFIGS. 11 through 13.

At block1910, the UE or base station may select a first filter length for a first bandpass filtering procedure to be performed on the first subset and select a second filter length for a second bandpass filtering procedure to be performed on the second subset of the set of tones. The operations of block1910may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block1910may be performed by a filter selection component as described with reference toFIGS. 11 through 13.

At block1915, the UE or base station may apply a first filter length to the first subset of the set of tones and a second filter length to the second subset of the set of tones in a bandpass filtering procedure, the second filter length being longer than the first filter length. The operations of block1915may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block1915may be performed by a filter component as described with reference toFIGS. 11 through 13.

At block1920, the UE or base station may overlap and add the filtered first subset of samples and the filtered second subset of samples to obtain the first transmission waveform. The operations of block1920may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block1920may be performed by a waveform generation component as described with reference toFIGS. 11 through 13.

At block1925, the UE or base station may transmit the first transmission waveform. The operations of block1925may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block1925may be performed by a transmitter as described with reference toFIGS. 11 through 13.

FIG. 20shows a flowchart illustrating a method2000for heterogeneous filtering for OFDM waveforms in accordance with various aspects of the present disclosure. The operations of method2000may be implemented by a UE or base station or its components as described herein. For example, the operations of method2000may be performed by a communication manager as described with reference toFIGS. 11 through 13. In some examples, a UE or base station may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE or base station may perform aspects the functions described below using special-purpose hardware.

At block2005, the UE or base station may identify a set of tones of a first symbol, a first subset of the set of tones, and a second subset of the set of tones. The operations of block2005may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block2005may be performed by a tone identifying component as described with reference toFIGS. 11 through 13.

At block2010, the UE or base station may select a first filter length for a first bandpass filtering procedure to be performed on the first subset of the set of tones and select a second filter length for a second bandpass filtering procedure to be performed on the second subset of the set of tones. The operations of block2010may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block2010may be performed by a filter selection component as described with reference toFIGS. 11 through 13.

At block2015, the UE or base station may add a cyclic prefix to the subsets of time domain samples and bandpass filter the cyclic prefix and the subsets of time domain samples based on the filter length for the corresponding subset. The operations of block2015may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block2015may be performed by a filter component as described with reference toFIGS. 11 through 13.

At block2020, the UE or base station may overlap and add the filtered first subset of samples and the filtered second subset of samples to obtain the first transmission waveform. The operations of block2020may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block2025may be performed by a waveform generation component as described with reference toFIGS. 11 through 13.

At block2025, the UE or base station may transmit the first transmission waveform. The operations of block2025may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block2025may be performed by a transmitter as described with reference toFIGS. 11 through 13.

FIG. 21shows a flowchart illustrating a method2100for heterogeneous filtering for OFDM waveforms in accordance with various aspects of the present disclosure. The operations of method2100may be implemented by a UE or base station or its components as described herein. For example, the operations of method2100may be performed by a communication manager as described with reference toFIGS. 11 through 13. In some examples, a UE or base station may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE or base station may perform aspects the functions described below using special-purpose hardware.

At block2105, the UE or base station may identify a set of tones of a first symbol, a first subset of the set of tones, and a second subset of the set of tones. The operations of block2105may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block2105may be performed by a tone identifying component as described with reference toFIGS. 11 through 13.

At block2110, the UE or base station may select a first filter length for a first bandpass filtering procedure to be performed on the first subset of the set of tones and select a second filter length for a second bandpass filtering procedure to be performed on the second subset of the set of tones. The operations of block2110may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block2110may be performed by a filter selection component as described with reference toFIGS. 11 through 13.

At block2115, the UE or base station may add a guard interval to subsets of time domain samples corresponding to the subsets of the set of tones and bandpass filter the guard interval and the subsets of time domain samples based at least in part on the corresponding selected filter length. The operations of block2115may be performed according to the methods described with reference toFIG. 6 through 10. In certain examples, aspects of the operations of block2115may be performed by a filter component as described with reference toFIGS. 11 through 13.

At block2120, the UE or base station may align and add the filtered first subset of samples and the filtered second subset of samples to obtain the first transmission waveform. The operations of block2120may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block2125may be performed by a waveform generation component as described with reference toFIGS. 11 through 13.

At block2125, the UE or base station may transmit the first transmission waveform. The operations of block2125may be performed according to the methods described with reference toFIGS. 6 through 10. In certain examples, aspects of the operations of block2125may be performed by a transmitter as described with reference toFIGS. 11 through 13.

FIG. 22Aillustrates an example of transmit processing chains2200for heterogeneous WOLA windowing for SC-FDMA waveforms. In some cases, processing chains2200may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, various examples may divide discrete Fourier transform (DFT) spread tones of a SC-FDMA symbols (e.g., M-point DFT2290resulting tones), after subcarrier mapping2295, into two or more subsets of tones, and each subset of tones may be processed separately for WOLA weighting. In the example ofFIG. 22A, edge tones2205may include a subset of tones at the head, or beginning, of a SC-FDMA symbol (e.g., edge tones2205-a). The edge tones2205-amay be provided to IFFT2210that may generate a number of samples corresponding to edge tones2205-a, which may be provided to a parallel to serial conversion2215function to generate a series of time samples corresponding to edge tones2205-a. A CP and extension with length L2may be added to the time samples at2220, and a weighting function2225performed with a weighting length L2that corresponds to extension length L2.

Similarly, center tones2230may include a subset of tones around the center of the SC-FDMA symbol. The center tones2230may be provided to IFFT2235that may generate a number of samples corresponding to center tones2230, which may be provided to a parallel to serial conversion2240function to generate a series of time samples corresponding to center tones2230. A CP and extension with length L1may be added to the time samples at2245, and a weighting function2250performed with a weighting length L1that corresponds to extension length L1.

Likewise, edge tones2205may include a subset of tones at the tail, or end, of the SC-FDMA symbol (e.g., edge tones2205-b). The edge tones2205-bmay be provided to IFFT2260that may generate a number of samples corresponding to edge tones2205-b, which may be provided to a parallel to serial conversion2265function to generate a series of time samples corresponding to edge tones2205-b. A CP and extension with length L3may be added to the time samples at2270, and a weighting function2275performed with a weighting length L3that corresponds to extension length L3.

Each of the weighted sub-symbols may be provided to alignment and sub-symbol addition function2280that may assemble the weighted sub-symbols to provide a transmission waveform for the SC-FDMA symbol. The transmission waveform may be provided to overlap and add function2285to provide an overlapped and added waveform with adjacent symbols, that may then be transmitted by a transmitter.

As discussed above, in some examples the weighting length L1may be selected to be shorter than the weighting length L2, which may provide reduced ISI effects at the center tones2230, and reduced ICI effects and improved OOB suppression for head tones405and edge tones2205-b. In some examples, the lengths L2and L3may be the same length, in which case the processing for both the edge tones2205-aand the edge tones2205-bmay be performed in the same processing chain.

FIG. 22Billustrates an example of receive processing chains22000for heterogeneous WOLA windowing for SC-FDMA waveforms. In some cases, processing chains22000may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, various examples may divide DFT spread tones of a SC-FDMA symbol into two or more subsets of tones, and each subset of tones may be processed separately for WOLA weighting. In the example ofFIG. 22B, a receiver may receive a SC-FDMA symbol waveform, and may truncate the received waveform for the SC-FDMA symbol at22005. Processing for head tones (e.g., edge tones22025-a) may include weighting the received waveform at a weighting function22010performed with a weighting length L2that corresponds to extension length L2. The weighted samples may be provided to a serial to parallel conversion22015function, and provided to FFT22020, that may output the edge tones22025-a(e.g., head tones).

Similarly, center tones22045may include a subset of tones around the center of the SC-FDMA symbol. The center tones22045processing may include weighting the received waveform at a weighting function22030performed with a weighting length L1that corresponds to extension length L1. The weighted samples may be provided to a serial to parallel conversion22035function, and provided to FFT22040, that may output the center tones22045.

Likewise, edge tones22025-bmay include a subset of tones at the tail, or end, of the SC-FDMA symbol. The edge tones22025-bprocessing may include weighting the received waveform at a weighting function22050performed with a weighting length L3that corresponds to extension length L3. The weighted samples may be provided to a serial to parallel conversion22055function, and provided to FFT22060, that may output the edge tones22025-b(e.g., tail tones).

As discussed above, in some examples the weighting length L1may be selected to be shorter than the weighting length L2, which may provide reduced ISI effects at the center tones22045, and reduced ICI effects and improved OOB suppression for edge tones22025.

The edge tones22025and center tones22045may then be passed to a subcarrier de-mapper (e.g., subcarrier demapping22065) to select the assigned M tones. These tones may then be de-spread via M-point IDFT22070.

FIG. 23Aillustrates an example of transmit processing chains2300for heterogeneous transmission filtering for SC-FDMA waveforms. In some cases, processing chains2300may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, various examples may divide DFT spread tones of a SC-FDMA symbols (e.g., M-point DFT2390resulting tones), after subcarrier mapping2395, into two or more subsets of tones, and in some examples each subset of tones may be filtered separately. In the example ofFIG. 23A, edge tones2305may include a subset of tones at the head, or beginning, of a SC-FDMA symbol (e.g., edge tones2305-a). The edge tones2305-a(e.g., head tones) may be provided to IFFT2310that may generate a number of samples corresponding to edge tones2305-a, which may be provided to a parallel to serial conversion2315function to generate a series of time samples corresponding to edge tones2305-a. A CP may be added to the time samples at2320, and the CP and time samples may be filtered with a filter length L2at bandpass filter2325.

Similarly, center tones2330may include a subset of tones around the center of the SC-FDMA symbol. The center tones2330may be provided to IFFT2335that may generate a number of samples corresponding to center tones2330, which may be provided to a parallel to serial conversion2340function to generate a series of time samples corresponding to center tones2330. A CP may be added to the time samples at2345, and the CP and time samples may be filtered with a filter length L1at bandpass filter2350.

Likewise, edge tones2305may include a subset of tones at the tail, or end, of the SC-FDMA symbol (e.g., edge tones2305-b). The edge tones2305-b(e.g., tail tones) may be provided to IFFT2360that may generate a number of samples corresponding to edge tones2305-b, which may be provided to a parallel to serial conversion2365function to generate a series of time samples corresponding to edge tones2305-b. A CP may be added to the time samples at2370, and the CP and time samples may be filtered with a filter length L3at bandpass filter2375.

Each of the filtered sub-symbols may be provided to alignment and sub-symbol addition function2380that may assemble the filtered sub-symbols to provide a transmission waveform for the SC-FDMA symbol. The transmission waveform may be provided to overlap and add function2385to provide an overlapped and added waveform with adjacent symbols, that may then be transmitted by a transmitter.

As discussed above, in some examples the filter length L1may be selected to be shorter than the filter length L2, which may provide reduced ISI effects at the center tones2330, and reduced ICI effects and improved OOB suppression for edge tones2305(e.g., head tones and tail tones). In some examples, the lengths L1and L2may be the same length, in which case the processing for both the edge tones2305-a(e.g., head tones) and the edge tones2305-b(e.g., tail tones) may be performed in the same processing chain.

FIG. 23Billustrates an example of receive processing chains23000for heterogeneous transmission filtering for SC-FDMA waveforms. In some cases, processing chains2300may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, various examples may divide DFT spread tones of a SC-FDMA symbols into two or more subsets of tones, and in some examples each subset of tones may be filtered separately. In the example ofFIG. 23B, edge tones23030may include a subset of tones at the head, or beginning, of a SC-FDMA symbol (e.g., edge tones23030-a). In the example ofFIG. 23B, a receiver may receive a SC-FDMA symbol waveform at23005. Processing for edge tones23030-a(e.g., head tones) may include bandpass filtering the received waveform at a filtering function23010performed with a filter length L2. The filtered samples may be truncated to a size corresponding to the transmit FFT size at truncation function23015, with the truncated waveform provided to a serial to parallel conversion23020function, and provided to FFT23025, that may output the edge tones23030-a.

Similarly, center tones23055may include a subset of tones around the center of the SC-FDMA symbol. The center tones23055processing may include bandpass filtering the received waveform at a filtering function23035performed with a filter length L1. The filtered samples may be truncated to a size corresponding to the transmit FFT size at truncation function23040, with the truncated waveform provided to a serial to parallel conversion23045function, and provided to FFT23050, that may output the center tones23055.

Likewise, edge tones23030may include a subset of tones at the tail, or end, of the SC-FDMA symbol (e.g., edge tones23030-b). The edge tones23030-b(e.g., tail tones) processing may include bandpass filtering the received waveform at a filtering function23060performed with a filter length L3. The filtered samples may be truncated to a size corresponding to the transmit FFT size at truncation function23065, with the truncated waveform provided to a serial to parallel conversion23070function, and provided to FFT23075, that may output the edge tones23030-b.

As discussed above, in some examples the filter length L1may be selected to be shorter than the filter length L2, which may provide reduced ISI effects at the center tones23055, and reduced ICI effects and improved OOB suppression for edge tones23030(e.g., head tones and tail tones).

The edge tones23030and center tones23055may then be passed to a subcarrier de-mapper (e.g., subcarrier demapping22085) to select the assigned M tones. These tones may then be de-spread via M-point IDFT22090.

FIG. 24Aillustrates an example of transmit processing chains2400for heterogeneous transmission filtering for SC-FDMA waveforms with guard intervals. In some cases, processing chains2400may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, again various examples may divide DFT spread tones of a SC-FDMA symbols (e.g., M-point DFT2490resulting tones), after subcarrier mapping2495, into two or more subsets of tones, and in some examples each subset of tones may be filtered separately. In the example ofFIG. 24A, edge tones2405may include a subset of tones at the head, or beginning, of a SC-FDMA symbol (e.g., edge tones2405-a). The edge tones2405-a(e.g., head tones) may be provided to IFFT2410that may generate a number of samples corresponding to edge tones2405-a, which may be provided to a parallel to serial conversion2415function to generate a series of time samples corresponding to edge tones2405-a. A guard interval may be added to the time samples at2420, and guard interval and time samples may be filtered with a filter length L2at bandpass filter2425. In some examples, the guard interval may be a zero power guard interval where no power is used in the transmissions for the period of the guard interval.

Similarly, center tones2430may include a subset of tones around the center of the SC-FDMA symbol. The center tones2430may be provided to IFFT2435that may generate a number of samples corresponding to center tones2430, which may be provided to a parallel to serial conversion2440function to generate a series of time samples corresponding to center tones2430. A guard interval may be added to the time samples at2445, and the guard interval and time samples may be filtered with a filter length L1at bandpass filter2450.

Likewise, edge tones2405may include a subset of tones at the tail, or end, of the SC-FDMA symbol (e.g., edge tones2405-b). The edge tones2405-b(e.g., tail tones) may be provided to IFFT2460that may generate a number of samples corresponding to edge tones2405-b, which may be provided to a parallel to serial conversion2465function to generate a series of time samples corresponding to edge tones2405-b. A guard interval may be added to the time samples at2470, and the guard interval and time samples may be filtered with a filter length L3at bandpass filter2475.

Each of the filtered sub-symbols may be provided to alignment and sub-symbol addition function2480that may assemble the filtered sub-symbols to provide a transmission waveform for the SC-FDMA symbol. The transmission waveform may be concatenated at2485with adjacent symbols and may be transmitted by a transmitter.

As discussed above, in some examples the filter length L1may be selected to be shorter than the filter length L2, which may provide reduced ISI effects at the center tones2430, and reduced ICI effects and improved OOB suppression for edge tones2405(e.g., head tones and tail tones).

FIG. 24Billustrates an example of receive processing chains24000for heterogeneous transmission filtering for SC-FDMA waveforms with guard intervals. In some cases, processing chains24000may represent aspects of techniques performed by a UE or base station as described with reference toFIGS. 1-2.

As discussed above, again various examples may divide DFT spread tones of a SC-FDMA symbols into two or more subsets of tones, and in some examples each subset of tones may be filtered separately. In the example ofFIG. 24B, edge tones24030-a(e.g., head tones) may include a subset of tones at the head, or beginning, of a SC-FDMA symbol. A receiver may receive a SC-FDMA symbol waveform at24005. Processing for edge tones24030-a(e.g., head tones) may include bandpass filtering the received waveform at a filtering function24010performed with a filter length L2. The filtered samples may be truncated to a size corresponding to the transmit FFT size plus a guard interval length at truncation function24015, with the truncated waveform provided to a zero-padding function24017to zero pad the waveform to the transmit IFFT size. The padded output is provided to serial to parallel conversion24020function, and provided to a 2-times size FFT24025. The FFT output may be downsampled by two at downsampling function24027, that may output the edge tones24030-a.

Similarly, center tones24055may include a subset of tones around the center of the SC-FDMA symbol. The center tones24055processing may include bandpass filtering the received waveform at a filtering function24035performed with a filter length L1. The filtered samples may be truncated to a size corresponding to the transmit FFT size plus a guard interval length at truncation function24040, with the truncated waveform provided to a zero-padding function24042to zero pad the waveform to the transmit IFFT size. The padded output is provided to serial to parallel conversion24045function, and provided to a 2-times size FFT24050. The FFT output may be downsampled by two at downsampling function24052, that may output the center tones24055.

Likewise, edge tones24030-b(e.g., tail tones) may include a subset of tones at the tail, or end, of the SC-FDMA symbol. The edge tones24030-bprocessing may bandpass filtering the received waveform at a filtering function24060performed with a filter length L3. The filtered samples may be truncated to a size corresponding to the transmit FFT size plus a guard interval length at truncation function24065, with the truncated waveform provided to a zero-padding function24067to zero pad the waveform to the transmit IFFT size. The padded output is provided to serial to parallel conversion24070function, and provided to a 2-times size FFT24075. The FFT output may be downsampled by two at downsampling function24077, that may output the edge tones24030-b.

As discussed above, in some examples the filter length L1may be selected to be shorter than the filter length L2, which may provide reduced ISI effects at the center tones24055, and reduced ICI effects and improved OOB suppression for edge tones24030(e.g., head tones and tail tones).

The edge tones24030and center tones24055may then be passed to a subcarrier de-mapper (e.g., subcarrier demapping24085) to select the assigned M tones. These tones may then be de-spread via M-point IDFT24090.

Uplink transmissions using SC-FDMA (or other multiple access technologies), and the WOLA weighting or bandpass filtering techniques described herein may be applied to such uplink symbols that are transmitted from a UE according to the examples described above with reference toFIGS. 5-24. The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel techniques disclosed herein.