Patent Description:
A wireless multiple-access communications system may include a number of base stations (BSs), each simultaneously supporting communications for multiple communication devices, which may be otherwise known as user equipment (UE).

To meet the growing demands for expanded mobile broadband connectivity, wireless communication technologies are advancing from the LTE technology to a next generation new radio (NR) technology. For example, NR is designed to provide a lower latency, a higher bandwidth or throughput, and a higher reliability than LTE. NR is designed to operate over a wide array of spectrum bands, for example, from low-frequency bands below about <NUM> gigahertz (GHz) and mid-frequency bands from about <NUM> to about <NUM>, to high-frequency bands such as millimeter wave (mmWave) bands. NR is also designed to operate across different spectrum types, from licensed spectrum to unlicensed and shared spectrum. Spectrum sharing enables operators to opportunistically aggregate spectrums to dynamically support high-bandwidth services. Spectrum sharing can extend the benefit of NR technologies to operating entities that may not have access to a licensed spectrum.

Some spectrums may have certain power spectral density (PSD) requirements. For example, the European Telecommunications Standard Institute (ETSI) document EN <NUM><NUM> V2. <NUM> specifies various PSD limits for sub-<NUM> frequency bands and the ETSI draft document EN <NUM><NUM> V2. <NUM> specifies a maximum equivalent isotropic radiated power (EIRP) and an EIRP density for <NUM> frequency bands. Some other frequency bands, such as citizens broadband radio service (CBRS) bands at about <NUM>, may not restrict transmissions to a particular PSD limit. In general, different spectrums may have different PSD requirements and/or different bandwidth occupancy requirements.

One approach to meeting the PSD requirement of a frequency spectrum and allowing a wireless communication device to transmit in the frequency spectrum at a full transmit power is to spread the frequency occupancy of a transmission signal over a wider bandwidth. However, the spreading of the frequency occupancy reduces the number of users that can be frequency-multiplexed in the frequency spectrum.

<NPL>, discusses the UL signals and channel design in NR-U with multiple channels in UL. <NPL>et al, summarizes the contributors' views and preferences regarding the remaining details of DFT-S-OFDMA based A/N signaling scheme. United States Patent Application Publication No. <CIT> relates to uplink control channel configuration for unlicensed carriers.

The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. Its sole purpose is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

For example, in an aspect of the disclosure, a method of wireless communication, comprises identifying, by a first wireless communication device, a first block-spreading code from a set of block-spreading codes associated with user multiplexing; generating, by the first wireless communication device, a first communication signal by: block-spreading a first block of information symbols based on the first block-spreading code to generate a first block of spread information symbols; performing a discrete Fourier transform, DFT, on the first block of spread information symbols to generate a frequency signal; and mapping the frequency signal to the set of resource blocks, RBs, wherein non-zero values of the frequency signal are located at the first set of subcarriers; and communicating, by the first wireless communication device with a second wireless communication device using a frequency interlace in a frequency spectrum, the first communication signal including the first block of information symbols spread across the set of RBs within the frequency interlace based on the first block-spreading code, wherein the first block of information symbols is carried by a first set of subcarriers interlaced with a second set of subcarriers in the set of RBs.

In an additional aspect of the disclosure, an apparatus comprises: means for identifying a first block-spreading code from a set of block-spreading codes associated with user multiplexing; means for generating, by the first wireless communication device, a first communication signal comprising: means for block-spreading a first block of information symbols based on the first block-spreading code to generate a first block of spread information symbols; means for performing a discrete Fourier transform, DFT, on the first block of spread information symbols to generate a frequency signal; and means for mapping the frequency signal to a set of resource blocks, RBs, wherein non-zero values of the frequency signal are located at the first set of subcarriers; and means for communicating, with a first wireless communication device using a frequency interlace in a frequency spectrum, a first communication signal including the first block of information symbols spread across the set of RBs within the frequency interlace based on the first block-spreading code.

This disclosure relates generally to wireless communications systems, also referred to as wireless communications networks. In various embodiments, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, <NUM>th Generation (<NUM>) or new radio (NR) networks, as well as other communications networks. As described herein, the terms "networks" and "systems" may be used interchangeably.

In particular, <NUM> networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. In order to achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for <NUM> NR networks. The <NUM> NR will be capable of scaling to provide coverage (<NUM>) to a massive Internet of things (IoTs) with an ultra-high density (e.g., ~<NUM> nodes/km<NUM>), ultra-low complexity (e.g., ~<NUM> of bits/sec), ultra-low energy (e.g., ~<NUM>+ years of battery life), and deep coverage with the capability to reach challenging locations; (<NUM>) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., ~<NUM>% reliability), ultra-low latency (e.g., ~ <NUM>), and users with wide ranges of mobility or lack thereof; and (<NUM>) with enhanced mobile broadband including extreme high capacity (e.g., ~ <NUM> Tbps/km<NUM>), extreme data rates (e.g., multi-Gbps rate, <NUM>+ Mbps user experienced rates), and deep awareness with advanced discovery and optimizations.

The <NUM> NR may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI); having a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD)/frequency division duplex (FDD) design; and with advanced wireless technologies, such as massive multiple input, multiple output (MIMO), robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in <NUM> NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than <NUM> FDD/TDD implementations, subcarrier spacing may occur with <NUM>, for example over <NUM>, <NUM>, <NUM>, and the like bandwidth (BW). For other various outdoor and small cell coverage deployments of TDD greater than <NUM>, subcarrier spacing may occur with <NUM> over <NUM>/<NUM> BW. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the <NUM> band, the subcarrier spacing may occur with <NUM> over a <NUM> BW. Finally, for various deployments transmitting with mmWave components at a TDD of <NUM>, subcarrier spacing may occur with <NUM> over a <NUM> BW.

The present application describes mechanisms for improving user multiplexing with DFT precoded frequency interlaces. For example, a BS may assign multiple UEs to transmit uplink information on the same frequency interlace. The BS may assign different UEs with different block-spreading codes that are orthogonal to each other. The block-spreading codes can be orthogonal cover codes (OCCs). A UE may generate a block of information symbols carrying uplink information (e.g., control information). The UE may apply block-spreading to the information symbols using an assigned block-spreading code. The UE may perform DFT spreading or DFT precoding on the block of spread information symbols to produce a frequency signal. The UE may map the frequency signal to the frequency interlace. The block-spreading, the DFT, and the frequency interlace mapping operations in effect spread the block of information across the entire DFT precoded frequency interlace.

In an embodiment, the UE may further perform time-domain spreading across multiple time-domain symbols (e.g., single carrier-frequency division multiplexing (SC-FDM) symbols). In an embodiment, the UE may further perform code-hopping across multiple time-domain symbols. While the disclosed embodiments are described in the context of physical uplink control channel (PUCCH) transmissions in a shared spectrum or an unlicensed spectrum, the disclose embodiments can be applied to any channel signal transmissions, such as physical uplink shared channel (PUSCH) transmissions, in any spectrum.

<FIG> illustrates a wireless communication network <NUM> according to some embodiments of the present disclosure. The network <NUM> may be a <NUM> network. The network <NUM> includes a number of base stations (BSs) <NUM> and other network entities. A BS <NUM> may be a station that communicates with UEs <NUM> and may also be referred to as an evolved node B (eNB), a next generation eNB (gNB), an access point, and the like. Each BS <NUM> may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to this particular geographic coverage area of a BS <NUM> and/or a BS subsystem serving the coverage area, depending on the context in which the term is used.

The UEs <NUM> are dispersed throughout the wireless network <NUM>, and each UE <NUM> may be stationary or mobile. A UE <NUM> may also be referred to as a terminal, a mobile station, a subscriber unit, a station, or the like. A UE <NUM> may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like. In one aspect, a UE <NUM> may be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, a UE may be a device that does not include a UICC. In some aspects, the UEs <NUM> that do not include UICCs may also be referred to as IoT devices or internet of everything (IoE) devices. The UEs 115a-115d are examples of mobile smart phone-type devices accessing network <NUM> A UE <NUM> may also be a machine specifically configured for connected communication, including machine type communication (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT) and the like. The UEs 115e-<NUM> are examples of various machines configured for communication that access the network <NUM>. A UE <NUM> may be able to communicate with any type of the BSs, whether macro BS, small cell, or the like. In <FIG>, a lightning bolt (e.g., communication links) indicates wireless transmissions between a UE <NUM> and a serving BS <NUM>, which is a BS designated to serve the UE <NUM> on the downlink and/or uplink, or desired transmission between BSs, and backhaul transmissions between BSs.

The network <NUM> may also support mission critical communications with ultra-reliable and redundant links for mission critical devices, such as the UE 115e, which may be a drone. Redundant communication links with the UE 115e may include links from the macro BSs 105d and 105e, as well as links from the small cell BS 105f. Other machine type devices, such as the UE 115f (e.g., a thermometer), the UE <NUM> (e.g., smart meter), and UE <NUM> (e.g., wearable device) may communicate through the network <NUM> either directly with BSs, such as the small cell BS 105f, and the macro BS 105e, or in multi-hop configurations by communicating with another user device which relays its information to the network, such as the UE 115f communicating temperature measurement information to the smart meter, the UE <NUM>, which is then reported to the network through the small cell BS 105f. The network <NUM> may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as in a vehicle-to-vehicle (V2V).

In some implementations, the network <NUM> utilizes OFDM-based waveforms for communications. An OFDM-based system may partition the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, bins, or the like. Each subcarrier may be modulated with data. In some instances, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system BW. The system BW may also be partitioned into subbands. In other instances, the subcarrier spacing and/or the duration of TTIs may be scalable.

In an embodiment, the BSs <NUM> can assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RB)) for downlink (DL) and uplink (UL) transmissions in the network <NUM>. DL refers to the transmission direction from a BS <NUM> to a UE <NUM>, whereas UL refers to the transmission direction from a UE <NUM> to a BS <NUM>. The communication can be in the form of radio frames. A radio frame may be divided into a plurality of subframes, for example, about <NUM>. Each subframe can be divided into slots, for example, about <NUM>. Each slot may be further divided into mini-slots. In a FDD mode, simultaneous UL and DL transmissions may occur in different frequency bands. For example, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In a TDD mode, UL and DL transmissions occur at different time periods using the same frequency band. For example, a subset of the subframes (e.g., DL subframes) in a radio frame may be used for DL transmissions and another subset of the subframes (e.g., UL subframes) in the radio frame may be used for UL transmissions.

The DL subframes and the UL subframes can be further divided into several regions. For example, each DL or UL subframe may have pre-defined regions for transmissions of reference signals, control information, and data. Reference signals are predetermined signals that facilitate the communications between the BSs <NUM> and the UEs <NUM>. For example, a reference signal can have a particular pilot pattern or structure, where pilot tones may span across an operational BW or frequency band, each positioned at a pre-defined time and a pre-defined frequency. For example, a BS <NUM> may transmit cell specific reference signals (CRSs) and/or channel state information - reference signals (CSI-RSs) to enable a UE <NUM> to estimate a DL channel. Similarly, a UE <NUM> may transmit sounding reference signals (SRSs) to enable a BS <NUM> to estimate a UL channel. Control information may include resource assignments and protocol controls. Data may include protocol data and/or operational data. In some embodiments, the BSs <NUM> and the UEs <NUM> may communicate using self-contained subframes. A self-contained subframe may include a portion for DL communication and a portion for UL communication. A self-contained subframe can be DL-centric or UL-centric. A DL-centric subframe may include a longer duration for DL communication than for UL communication. A UL-centric subframe may include a longer duration for UL communication than for UL communication.

In an embodiment, the network <NUM> may be an NR network deployed over a licensed spectrum. The BSs <NUM> can transmit synchronization signals (e.g., including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS)) in the network <NUM> to facilitate synchronization. The BSs <NUM> can broadcast system information associated with the network <NUM> (e.g., including a master information block (MIB), remaining minimum system information (RMSI), and other system information (OSI)) to facilitate initial network access. In some instances, the BSs <NUM> may broadcast the PSS, the SSS, and/or the MIB in the form of synchronization signal blocks (SSBs) over a physical broadcast channel (PBCH) and may broadcast the RMSI and/or the OSI over a physical downlink shared channel (PDSCH).

In an embodiment, a UE <NUM> attempting to access the network <NUM> may perform an initial cell search by detecting a PSS from a BS <NUM>. The PSS may enable synchronization of period timing and may indicate a physical layer identity value. The UE <NUM> may then receive a SSS. The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The SSS may also enable detection of a duplexing mode and a cyclic prefix length. Some systems, such as TDD systems, may transmit an SSS but not a PSS. Both the PSS and the SSS may be located in a central portion of a carrier, respectively.

After receiving the PSS and SSS, the UE <NUM> may receive a MIB. The MIB may include system information for initial network access and scheduling information for RMSI and/or OSI. After decoding the MIB, the UE <NUM> may receive RMSI and/or OSI. The RMSI and/or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical uplink control channel (PUCCH), physical uplink shared channel (PUSCH), power control, SRS, and cell barring.

After obtaining the MIB, the RMSI and/or the OSI, the UE <NUM> can perform a random access procedure to establish a connection with the BS <NUM>. For the random access procedure, the UE <NUM> may transmit a random access preamble and the BS <NUM> may respond with a random access response. Upon receiving the random access response, the UE <NUM> may transmit a connection request to the BS <NUM> and the BS <NUM> may respond with a connection response (e.g., contention resolution message).

After establishing a connection, the UE <NUM> and the BS <NUM> can enter a normal operation stage, where operational data may be exchanged. For example, the BS <NUM> may schedule the UE <NUM> for UL and/or DL communications. The BS <NUM> may transmit UL and/or DL scheduling grants to the UE <NUM> via a PDCCH. The BS <NUM> may transmit a DL communication signal to the UE <NUM> via a PDSCH according to a DL scheduling grant. The UE <NUM> may transmit a UL communication signal to the BS <NUM> via a PUSCH and/or PUCCH according to a UL scheduling grant.

In an embodiment, the network <NUM> may operate over a system BW or a component carrier (CC) BW. The network <NUM> may partition the system BW into multiple BWPs (e.g., portions). A BS <NUM> may dynamically assign a UE <NUM> to operate over a certain BWP (e.g., a certain portion of the system BW). The assigned BWP may be referred to as the active BWP. The UE <NUM> may monitor the active BWP for signaling information from the BS <NUM>. The BS <NUM> may schedule the UE <NUM> for UL or DL communications in the active BWP. In some embodiments, a BS <NUM> may assign a pair of BWPs within the CC to a UE <NUM> for UL and DL communications. For example, the BWP pair may include one BWP for UL communications and one BWP for DL communications.

During the normal operation stage, the UE <NUM> may transmit UL control information to a BS <NUM> over a PUCCH. The BS <NUM> may schedule the UE <NUM> for UL transmissions based on the received UL control information. Some examples of UL control information may include scheduling requests (SRs), channel state information (CSI)-reports, and/or hybrid automatic repeat request (HARQ) feedbacks (e.g., acknowledgements (ACKs) and/or not-ACKs). In some instances, a BS <NUM> may assign multiple UEs <NUM> with the same PUCCH resources (e.g., time-frequency resources) using multiplexing schemes.

In an embodiment, the network <NUM> may operate over various frequency bands, for example, in frequency ranges between about <NUM> to above <NUM>. Different frequency bands may have different PSD requirements. For example, certain frequency bands may have a maximum allowable PSD level of about <NUM> decibel-milliwatts per megahertz (dBm/MHz) to about <NUM> dBm/MHz. Thus, a transmitter having a full power of about <NUM> dBm may or may not be able to utilize the full power for a signal transmission depending on the signal frequency bandwidth. To satisfy a certain PSD requirement in a frequency spectrum, a transmitter (e.g., the BSs <NUM> and the UEs <NUM>) may distribute the frequency occupancy of a transmission signal over a wider bandwidth. For example, a transmitter may transmit a signal over multiple narrow frequency bands spaced apart from each other in a frequency bandwidth at a higher power than transmitting the signal over contiguous frequencies.

In an embodiment, a BS <NUM> may configure UEs <NUM> to communicate PUCCH information using frequency interlaces, where the PUCCH information may be distributed across the entire frequency interlace to increase bandwidth occupancy, for example, to meet certain PSD requirements. The BS may assign multiple UEs <NUM> on the same frequency interlace by using DFT precoding with block-spreading OCCs as described in greater detail herein.

<FIG> illustrates a resource configuration scheme with frequency interlaces according to some embodiments of the present disclosure. In <FIG>, the x-axis represents time in some constant units and the y-axis represents frequency in some constant units. The scheme <NUM> may be employed by BSs such as the BSs <NUM> and UEs such as the UEs <NUM> in a network such as the network <NUM> to communicate with each other over a frequency spectrum <NUM>. The frequency spectrum <NUM> may have a bandwidth of about <NUM> megahertz (MHz) or about <NUM> and a subcarrier spacing (SCS) of about <NUM> kilohertz (kHz), about <NUM>, or about <NUM>. The frequency spectrum <NUM> may be located at any suitable frequencies. In some embodiments, the frequency spectrum <NUM> may be located at about <NUM>, <NUM>, or <NUM>. The scheme <NUM> allocates resources in units of frequency interlaces <NUM>.

The frequency interlaces are shown as <NUM>I(<NUM>) to <NUM> I(M-<NUM>), where M is a positive integer. Each frequency interlace <NUM> may include K plurality of RBs <NUM> evenly spaced over the frequency spectrum <NUM>, where K is a positive integer. In other words, the RBs <NUM> in a particular frequency interlace <NUM>I(i) are spaced apart from each other by at least one other RB <NUM>, where i may vary between <NUM> and M-<NUM>. The values K and M may vary based on several factors, such as the bandwidth, the subcarrier spacing (SCS), and/or the PSD limitation of the frequency spectrum <NUM>, as described in greater detail herein. In some instances, the value K may also vary for different interlaces.

A group of M localized RBs <NUM> forms a cluster <NUM>. As shown, the frequency interlaces <NUM>I(<NUM>) to <NUM>(M-<NUM>) form K clusters <NUM>C(<NUM>) to <NUM>C(K-<NUM>). Each RB <NUM> may span about twelve contiguous subcarriers <NUM> in frequency and a time period <NUM>. The subcarriers <NUM> are indexed from <NUM> to <NUM>. The time period <NUM> may span any suitable number of OFDM symbols <NUM>. In some embodiments, the time period <NUM> may correspond to one transmission time interval (TTI), which may include about fourteen OFDM symbols <NUM>.

The number of clusters <NUM> or the value of K may be dependent on the amount of frequency distribution required to maintain a certain PSD level. As an example, the scheme <NUM> may divide the frequency spectrum <NUM> into about ten clusters <NUM> (e.g., K = <NUM>) and distribute an allocation over the ten clusters <NUM> to increase a frequency occupancy of the allocation. In an embodiment, the frequency spectrum <NUM> may have a bandwidth of about <NUM> and each subcarrier <NUM> may span about <NUM> in frequency. In such an embodiment, the frequency spectrum <NUM> may include about ten frequency interlaces <NUM> (e.g., M = <NUM>). For example, an allocation may include one frequency interlace <NUM> having ten distributed or equally spaced RBs <NUM>. Compared to an allocation with a single RB or ten localized RBs, the interlaced allocation with the ten distributed RBs <NUM> allows a UE to transmit at a higher power while maintaining the same PSD level.

In another embodiment, the frequency spectrum <NUM> may have a bandwidth of about <NUM> and each subcarrier <NUM> may span about <NUM> in frequency. In such an embodiment, the frequency spectrum <NUM> may include about five frequency interlaces <NUM> (e.g., M = <NUM>). Similarly, an allocation may include one frequency interlace <NUM> having ten distributed RBs <NUM>. The interlaced allocation with the ten distributed RBs may allow for better power utilization than an allocation with a single RB or ten localized RBs at the same PSD level.

In another embodiment, the frequency spectrum <NUM> may have a bandwidth of about <NUM> and each subcarrier <NUM> may span about <NUM> in frequency. In such an embodiment, the frequency spectrum <NUM> may include about five frequency interlaces <NUM> (e.g., M = <NUM>). Similarly, an allocation may include one frequency interlace <NUM> having ten distributed RBs <NUM>. The interlaced allocation with the ten distributed RBs may allow for better power utilization than an allocation with a single RB or ten localized RBs at the same PSD level.

The use of frequency interlacing to distribute an allocation into a wider bandwidth allows a transmitter to transmit at a higher power level than when an allocation occupies contiguous frequencies. As an example, the frequency spectrum <NUM> may have a maximum allowable PSD level of about <NUM> dBm/MHz and a transmitter (e.g., the UEs <NUM>) may have a power amplifier (PA) capable of transmitting at about <NUM> dBm. Distributing frequency occupancy of an allocation into five clusters <NUM> may allow the transmitter to transmit at about <NUM> dBm (e.g., with a power boost of about <NUM> dB) while maintaining a PSD level of about <NUM> dBm/MHz. Distributing frequency occupancy of an allocation into ten clusters <NUM> may allow the transmitter to transmit at a full power of about <NUM> dBm (e.g., with a power boost of about <NUM> dB) while maintaining a PSD level of about <NUM> dBm/MHz. Thus, the use of frequency interlacing can provide better power utilization.

In an embodiment, the scheme <NUM> may be applied to a PUCCH to provide a power boost at a transmitter (e.g., the UEs <NUM>). For example, one RB <NUM> may be sufficient to carry UCI of a particular PUCCH format signal. However, in order to meet the PSD requirement, a UE may extend the frequency occupancy of the PUCCH signal from one RB <NUM> to K RBs <NUM> by transmitting the PUCCH signal using one frequency interlace <NUM>. As noted earlier, interlaced waveforms can improve link budget for better coverage under PSD limit as it allows UE to transmit at a higher power level. However, with interlaced waveforms, each PUCCH occupies a greater number of RBs compared to a non-interlaced allocation. For example, the number of UEs that can be multiplexed over the frequency spectrum <NUM> for PUCCH signal transmissions may be reduced by a factor of about K if each UE only required one RB when there were no constraints on PSD.

One approach to increasing user multiplexing capacity in a frequency interlace <NUM> is to assign different UEs with different OCCs so that transmissions from the different UEs may not interfere with each other. Further, DFT spreading can be applied to reduce the peak-to-average power ratio (PAPR) of the transmissions. Thus, the OCC spreading can be referred to as a pre-DFT-OCC spreading.

<FIG>, <FIG>, <FIG>, and <FIG> illustrate mechanisms for applying pre-DFT-OCC spreading to increase user multiplexing capacity. The embodiments shown in <FIG>, <FIG>, <FIG> and <FIG> are not covered by the claims. For example, a BS may assign multiple UEs on the same frequency interlace (e.g., the frequency interlace <NUM>I(i)) for PUCCH transmissions and may assign each UE with a different OCC. The plots <NUM> in the right-side of <FIG> and <FIG> and the plots <NUM> in in the right-side of <FIG> and <FIG> include x-axes representing time in some constant units and y-axes representing frequency in some constant units.

<FIG> illustrates a transmission scheme <NUM> with pre-DFT-OCC spreading according to some embodiments of the present disclosure. The scheme <NUM> may be employed by BSs such as the BSs <NUM> and UEs such as the UEs <NUM> in a network such as the network <NUM> for PUCCH transmissions. The scheme <NUM> can be used in conjunction with the scheme <NUM>. For simplicity of discussions, <FIG> illustrates three information symbols <NUM> shown as D0, D1, and D2 spread by a length-<NUM> OCC <NUM> shown as C0, C1, C2, C3 across a cluster <NUM> prior to a DFT spreading. However, the embodiments of the present disclosure may scale to spread any suitable number of information symbols <NUM> (e.g., <NUM>, <NUM>, <NUM>, <NUM>, or more) using an OCC <NUM> of any suitable length (e.g., <NUM>, <NUM>, or more) across a cluster <NUM>. Additionally, the scheme <NUM> is described using the frequency interlace structure in <FIG>, and may use the same reference numerals as in <FIG> for simplicity sake.

For example, a UE generates three information symbols <NUM> carrying uplink control information (UCI). The information symbols <NUM> may be modulation symbols. The UE spreads each information symbol <NUM> by the OCC <NUM> and then concatenates the spread symbols <NUM> to form a sequence. In other words, the scheme <NUM> performs pre-DFT-OCC spreading based on symbol repetitions. The sequence of spread symbols <NUM> can be represented by {D0×C0, D0×C1, D0×C2, D0×C3, D1×C0, D1×C1, D1×C2, D1×C3, D2×C0, D2×C1, D2×C2, D2×C3}. The sequence of spread symbols <NUM> can be further spread by a DFT <NUM>. The DFT output can be mapped to an RB <NUM> of an assigned frequency interlace <NUM>I(<NUM>) within a cluster <NUM>c(<NUM>) as shown in the in plot <NUM>.

The scheme <NUM> may be extended to map more information symbols <NUM> over the entire frequency interlace <NUM>I(<NUM>). For example, the UE may further generate information symbols D3, D4, and D5 (e.g., the information symbols <NUM>) and apply the scheme <NUM> to spread the information symbols D3, D4, and D5 using the OCC <NUM> across a portion of the frequency interlace <NUM>I(<NUM>) within another cluster <NUM> (e.g., the cluster <NUM>c(<NUM>)). In other words, each symbol D3, D4, and D5 are repeated and then multiplied by the OCC <NUM>. Accordingly, the spreading by the OCC <NUM> produces a sequence {D3×C0, D3×C1, D3×C2, D3×C3, D4×C0, D4×C1, D4×C2, D4×C3, D5×C0, D5×C1, D5×C2, D5×C3}.

<FIG> is similar to <FIG>, but shows additional aspects of the scheme <NUM> (e.g., pre-DFT-OCC spreading for more information symbols <NUM>). As shown in <FIG>, pre-DFT-OCC spreading can be applied to information symbols <NUM> including D0, D1, D2, D3, D4, and D5. The pre-DFT-OCC spreading based on symbol repetitions in time and spreading by the OCC <NUM> (shown by the dotted-line box) as discussed above in <FIG> can be applied to the information symbols <NUM>. After the spreading by the OCC <NUM>, the DFT <NUM> is applied to the sequence of spread symbols {D0×C0, D0×C1, D0×C2, D0×C3, D1×C0, D1×C1, D1×C2, D1×C3, D2×C0, D2×C1, D2×C2, D2×C3, D3×C0, D3×C1, D3×C2, D3×C3, D4×C0, D4×C1, D4×C2, D4×C3, D5×C0, D5×C1, D5×C2, D5×C3}. In general, for N+<NUM> information symbols <NUM>, the sequence of symbols spread by the OCC <NUM> can be represented as {D0×C0, D0×C1, D0×C2, D0×C3,. , DN×C0, DN×C1, DN×C2, DN×C3} and the DFT <NUM> is applied across the sequence of spread symbols. The output of the DFT <NUM> is mapped to RBs <NUM> of the frequency interlace <NUM>I(<NUM>) as shown in the plot <NUM>.

<FIG> illustrates a transmission scheme <NUM> with pre-DFT-OCC spreading according to some embodiments of the present disclosure. The scheme <NUM> may be employed by BSs such as the BSs <NUM> and UEs such as the UEs <NUM> in a network such as the network <NUM> for a PUCCH transmission. The scheme <NUM> can be used in conjunction with the scheme <NUM>. The scheme <NUM> is described using a similar configuration as the scheme <NUM>, where three information symbols <NUM> are spread by a length-<NUM> OCC <NUM> shown as C0, C1, C2, C3 across a cluster <NUM> prior to a DFT spreading. Further, the scheme <NUM> is described using the frequency interlace structure in <FIG>, and may use the same reference numerals as in <FIG> for simplicity sake.

However, the scheme <NUM> performs the pre-DFT-OCC spreading using block repetitions instead of symbol repetitions.

As shown in <FIG>, the UE spreads the information symbols <NUM> as a block <NUM> by the OCC <NUM> to form a sequence of block-spread symbols <NUM>. The block-spread symbols <NUM> can be represented by {D0×C0, D1×C0, D2×C0, D0×C1, D1×C1, D2×C1, D0×C2, D1×C2, D2×C2, D0×C3, D1×C3, D2×C3}. Similar to the scheme <NUM>, the block-spread symbols can be further spread by a DFT <NUM> and the DFT output can be mapped to an RB <NUM> of an assigned frequency interlace <NUM>I(<NUM>) within a cluster <NUM>c(<NUM>) as shown in the in plot <NUM>.

The UE may further generate information symbols D3, D4, and D5 (e.g., the information symbols <NUM>) and repeat the scheme <NUM> to spread the information symbols D3, D4, and D5 as a block using the OCC <NUM> across a portion of the frequency interlace <NUM>I(<NUM>) within another cluster <NUM> (e.g., <NUM>c(<NUM>)). Accordingly, the spreading by the OCC <NUM> produces a sequence {D3×C0, D4×C0, D5×C0, D3×C1, D4×C1, D5×C1, D3×C2, D4×C2, D5×C2, D3×C3, D4×C3, D5×C3}.

<FIG> is similar to <FIG>, but shows additional aspects of the scheme <NUM> (e.g., pre-DFT-OCC spreading for more information symbols <NUM>). As shown in <FIG>, pre-DFT-OCC spreading can be applied to information symbols <NUM> including D0, D1, D2, D3, D4, and D5. The pre-DFT-OCC spreading based on block repetitions in time and spreading by the OCC <NUM> (shown by the dotted-line box) as discussed above in <FIG> can be applied to the information symbols <NUM>. After the spreading by the OCC <NUM>, the DFT <NUM> is applied to the sequence of spread symbols {D0×C0, D1×C0, D2×C0, D0×C1, D1×C1, D2×C1, D0×C2, D1×C2, D2×C2, D0×C3, D1×C3, D2×C3, D3×C0, D4×C0, D5×C0, D3×C1, D4×C1, D5×C1, D3×C2, D4×C2, D5×C2, D3×C3, D4×C3, D5×C3}. In general, for N+<NUM> information symbols <NUM>, the sequence of spread symbols can be represented as {D0×C0, D1×C0, D2×C0,. , DN×C3} and the DFT <NUM> is applied across the sequence of spread symbols. The output of the DFT <NUM> is mapped to RBs <NUM> of the frequency interlace <NUM>I(<NUM>) as shown in the plot <NUM>.

One drawback of the schemes <NUM> and <NUM> is that while the per cluster OCC spreading can provide orthogonality among transmissions from multiple users, the subsequent DFT spreading may not preserve the code-division multiplexing (CDM) orthogonality provided by the OCCs. In other words, the DFT output may include tones or resource elements (REs) (e.g., the subcarriers <NUM>) that carry useful signals from two or more UEs, causing interference among the UEs and degrading performance. In order to achieve a good performance without degradation, additional receiver processing (e.g., including a joint equalizer across UEs) can be applied. However, the complexity of the receive may increase, and thus may not be desirable.

Accordingly, the present invention provides techniques to perform pre-DFT-OCC for an increased user multiplexing capacity, but without the complex receiver processing or degraded performance as in the schemes <NUM> and <NUM>.

<FIG> is a block diagram of an exemplary UE <NUM> according to embodiments of the present disclosure. The UE <NUM> may be a UE <NUM> as discussed above. As shown, the UE <NUM> may include a processor <NUM>, a memory <NUM>, a pre-DFT-OCC-based communication module <NUM>, a transceiver <NUM> including a modem subsystem <NUM> and a radio frequency (RF) unit <NUM>, and one or more antennas <NUM>. These elements may be in direct or indirect communication with each other, for example via one or more buses.

The memory <NUM> may include a cache memory (e.g., a cache memory of the processor <NUM>), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an embodiment, the memory <NUM> includes a non-transitory computer-readable medium. The instructions <NUM> may include instructions that, when executed by the processor <NUM>, cause the processor <NUM> to perform the operations described herein with reference to the UEs <NUM> in connection with embodiments of the present disclosure. Instructions <NUM> may also be referred to as code. The terms "instructions" and "code" should be interpreted broadly to include any type of computer-readable statement(s). For example, the terms "instructions" and "code" may refer to one or more programs, routines, sub-routines, functions, procedures, etc. "Instructions" and "code" may include a single computer-readable statement or many computer-readable statements.

The pre-DFT-OCC-based communication module <NUM> may be implemented via hardware, software, or combinations thereof. For example, the pre-DFT-OCC-based communication module <NUM> may be implemented as a processor, circuit, and/or instructions <NUM> stored in the memory <NUM> and executed by the processor <NUM>. The pre-DFT-OCC-based communication module <NUM> may be used for various aspects of the present disclosure. For example, the pre-DFT-OCC-based communication module <NUM> is configured to receive an allocation for a transmission on a frequency interlace (e.g., the frequency interlace <NUM>) and an OCC (e.g., the OCCs <NUM>) from a BS (e.g., the BSs <NUM>), generate information symbols (e.g., the information symbols <NUM>), perform a block-spreading of the information symbols across the entire frequency interlace using the OCC, perform a DFT spreading after the OCC block-spreading, map the DFT output to the frequency interlace, transmit a signal including the pre-DFT-OCC block-spread information symbols to the BS, as described in greater detail herein.

As shown, the transceiver <NUM> may include the modem subsystem <NUM> and the RF unit <NUM>. The transceiver <NUM> can be configured to communicate bi-directionally with other devices, such as the BSs <NUM>. The modem subsystem <NUM> may be configured to modulate and/or encode the data from the memory <NUM>, and/or the pre-DFT-OCC-based communication module <NUM> according to a modulation and coding scheme (MCS), e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit <NUM> may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated/encoded data from the modem subsystem <NUM> (on outbound transmissions) or of transmissions originating from another source such as a UE <NUM> or a BS <NUM>. The RF unit <NUM> may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver <NUM>, the modem subsystem <NUM> and the RF unit <NUM> may be separate devices that are coupled together at the UE <NUM> to enable the UE <NUM> to communicate with other devices.

The RF unit <NUM> may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information), to the antennas <NUM> for transmission to one or more other devices. The antennas <NUM> may further receive data messages transmitted from other devices. The antennas <NUM> may provide the received data messages for processing and/or demodulation at the transceiver <NUM>. The antennas <NUM> may include multiple antennas of similar or different designs in order to sustain multiple transmission links. The RF unit <NUM> may configure the antennas <NUM>.

<FIG> is a block diagram of an exemplary BS <NUM> according to embodiments of the present disclosure. The BS <NUM> may be a BS <NUM> as discussed above. As shown, the BS <NUM> may include a processor <NUM>, a memory <NUM>, a pre-DFT-OCC-based communication module <NUM>, a transceiver <NUM> including a modem subsystem <NUM> and a RF unit <NUM>, and one or more antennas <NUM>. These elements may be in direct or indirect communication with each other, for example via one or more buses.

The pre-DFT-OCC-based communication module <NUM> may be implemented via hardware, software, or combinations thereof. For example, the pre-DFT-OCC-based communication module <NUM> may be implemented as a processor, circuit, and/or instructions <NUM> stored in the memory <NUM> and executed by the processor <NUM>. The pre-DFT-OCC-based communication module <NUM> may be used for various aspects of the present disclosure. For example, the pre-DFT-OCC-based communication module <NUM> is configured to multiplex multiple UEs (e.g., the UEs <NUM> and <NUM>) on the same frequency interlace (e.g., the frequency interlace <NUM>), assign each UE with an OCC (e.g., the OCC <NUM>) for block-spreading information symbols (e.g., the information symbols <NUM>) across the entire frequency interlace, receive a signal from the UE including pre-DFT-OCC block-spread information symbols, and/or process the received signal based on a certain set of tones or subcarriers dependent on the OCC assigned to the corresponding UE, as described in greater detail herein.

As shown, the transceiver <NUM> may include the modem subsystem <NUM> and the RF unit <NUM>. The transceiver <NUM> can be configured to communicate bi-directionally with other devices, such as the UEs <NUM> and/or another core network element. The modem subsystem <NUM> may be configured to modulate and/or encode data according to a MCS, e.g., a LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit <NUM> may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated/encoded data from the modem subsystem <NUM> (on outbound transmissions) or of transmissions originating from another source such as a UE <NUM> or <NUM>. The RF unit <NUM> may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver <NUM>, the modem subsystem <NUM> and/or the RF unit <NUM> may be separate devices that are coupled together at the BS <NUM> to enable the BS <NUM> to communicate with other devices.

The RF unit <NUM> may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information), to the antennas <NUM> for transmission to one or more other devices. This may include, for example, transmission of information to complete attachment to a network and communication with a camped UE <NUM> or <NUM> according to embodiments of the present disclosure. The antennas <NUM> may further receive data messages transmitted from other devices and provide the received data messages for processing and/or demodulation at the transceiver <NUM>. The antennas <NUM> may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

<FIG> illustrates a user multiplexing scheme <NUM> using DFT precoding with OCCs according to some embodiments of the present disclosure. The scheme <NUM> may be employed by BSs such as the BSs <NUM> and <NUM> and UEs such as the UEs <NUM> and <NUM> in a network such as the network <NUM>. The scheme <NUM> multiplexes a UE A and a UE B on the same resource (e.g., the same RB <NUM>). The scheme <NUM> applies OCC block-spreading across the entire set of RBs <NUM>. A BS may assign the UE A and the UE B with different OCCs. The BS may assign the UE A with an OCC 710a represented by {<NUM>, <NUM>}. The BS may assign the UE B with an OCC 710b represented by {<NUM>, -<NUM>}.

The UE A generates information symbols <NUM> shown as a0, a1, a2, a3, a4, and a5 (e.g., the information symbols <NUM>). The UE A applies an OCC 710a to block-spread the information symbols <NUM> in a time domain to form a sequence of block-spread symbols 712a. The block-spread symbols 712a, denoted as S<NUM>, can be expressed as shown below: <MAT> The UE A performs DFT spreading to the block-spread symbols 712a by applying a DFT <NUM> (e.g., the DFT <NUM>). Based on the FFT property described in greater detail below, the DFT output 722a, denoted as DFT(S<NUM>), is located on even tones (e.g., the subcarriers <NUM>) as shown by the pattern-filled boxes. The UE A maps the DFT output 722a to an assigned RB (e.g., RB <NUM>) and performs an inverse fast Fourier transform (IFFT) <NUM> to transform the DFT output 722a into a time domain signal, which may be referred as an SC-FDM symbol or a DFT-spreading-OFDM (DFT-s-OFDM) symbol. Accordingly, the time-domain signal may be referred to as a SC-FDM waveform signal or a DFT-s-OFDM waveform signal. The UE A applies a cyclic prefix (CP) add operation <NUM> to the time domain signal. The CP add operation <NUM> copies an end portion of the time domain signal to the beginning of the time domain signal. The UE A transmits the CP-added signal (e.g., an output signal 742a) to the BS.

Similarly, the UE B generates information symbols <NUM> shown as b0, b1, b2, b3, b4, and b5 (e.g., the information symbols <NUM>). The UE B applies an OCC 710b to block-spread the information symbols <NUM> to form a sequence of block-spread symbols 712b. The block-spread symbols 712b, denoted as S<NUM>, can be expressed as shown below: <MAT> The UE B performs DFT spreading to the block-spread symbols 712b by applying a DFT <NUM>. Based on the FFT property as described in greater detail below, the DFT output 722b, denoted as DFT(S<NUM>), is located on odd tones (e.g., the subcarriers <NUM>) as shown by the pattern-filled boxes. The UE B maps the DFT output 722b to the same RB that is assigned to the UE A. Subsequently, the UE B applies an IFFT <NUM>, followed by a CP add operation <NUM> to produce an output signal 742b. The UE B transmits the output signal 742b to the BS.

The FFT properties for the DFT output 722a (e.g., with even tones) at the UE A and the FFT properties for the DFT output 722b (e.g., with odd tones) at the UE B can be derived by examining FFT operations. For example, given a discrete time signal xn, where n = <NUM>,. , N - <NUM>, the FFT of xn, denoted as Xk, is given by: <MAT> where n represents the time indices and k represents the frequency indices.

When xn = xn+N/<NUM>, as in the signal 712a generated by the UE A, the DFT output 722a can be expressed as shown below: <MAT> As can be observed in Equation (<NUM>), when k is odd, Xk = <NUM>. Thus, the DFT output 722a includes non-zero values in even tones only.

Similarly, when xn = -xn+N/<NUM>, as in the signal 712b generated by the UE B, the DFT output 722b can be expressed as shown below: <MAT> As can be observed in Equation (<NUM>), when k is even, Xk = <NUM>. Thus, the DFT output 722b includes non-zero values in odd tones only. As can be further observed from Equations (<NUM>) and (<NUM>), the pre-DFT-OCC user multiplexing is equivalent to comb-based (e.g., FDM) user multiplexing as described in greater detail herein.

<FIG> illustrates a user multiplexing scheme <NUM> using FDM according to some embodiments of the present disclosure that are not covered by the claims. The scheme <NUM> uses a substantially similar transmission chain as the scheme <NUM>, but without the pre-DFT-OCC spreading as in the scheme <NUM>. As shown in <FIG>, a UE A generates information symbols <NUM> shown as a0, a1, a2, a3, a4, and a5. The UE A applies a DFT <NUM> to the information symbols <NUM>. The UE A maps the DFT output 822a to even tones (e.g., subcarriers <NUM>) within an assigned RB (e.g., the RB <NUM>) to form a frequency signal 824a. Subsequently, the UE A applies an IFFT <NUM>, followed by a CP add operation <NUM> to produce an output signal 842a.

Similarly, a UE B generates information symbols <NUM> shown as b0, b1, b2, b3, b4, and b5. The UE B applies a DFT <NUM> to the information symbols <NUM>. The UE B maps the DFT output 822b to odd tones in the same RB that is assigned to the UE A to form a frequency signal 824b. Subsequently, the UE B applies an IFFT <NUM>, followed by a CP add operation <NUM> to produce an output signal 842b.

<FIG> and <FIG> are similar to <FIG>, but provide a view of the FDM mechanisms of scheme <NUM> shown in <FIG> with mapping to a frequency interlace <NUM>I(<NUM>) assigned to the UE A (<FIG>) and the UE B (<FIG>). The embodiments shown in <FIG> and <FIG> are not covered by the claims. As shown in <FIG>, the UE A generates N+<NUM> number of information symbols <NUM>, shown as {a0, a1, a2,. , aN}, applies the DFT <NUM> to the information symbols <NUM>, and maps the DFT output 822a to even tones (e.g., subcarriers <NUM>) of RBs <NUM> within the frequency interlace <NUM>I(<NUM>) (as shown by interlace mapping <NUM>). Subsequently, the UE A applies an IFFT <NUM>, followed by a CP add operation <NUM> to produce an output signal 842a.

Similarly, in <FIG>, the UE B generates N+<NUM> number of information symbols <NUM>, shown as {b0, b1, b2,. , bN}, applies the DFT <NUM> to the information symbols <NUM>, and maps the DFT output 822b to odd tones (e.g., subcarriers <NUM>) of RBs <NUM> within the frequency interlace <NUM>I(<NUM>) (as shown by mapping <NUM>). Subsequently, the UE B applies an IFFT <NUM>, followed by a CP add operation <NUM> to produce an output signal 842b. The N value may be dependent on the number of RBs <NUM> in the frequency interlace <NUM>I(<NUM>) and the number of UEs multiplexed on the frequency interlace <NUM>I(<NUM>).

As can be observed from the schemes <NUM> and <NUM>, the pre-DFT-OCC spreading followed by the DFT spreading in the scheme <NUM> produce a similar orthogonal transmission structure among UEs as the FDM in the scheme <NUM>.

Accordingly, to multiplex four UEs, the Fourier basis can be used for OCC spreading with codes [<NUM>,<NUM>,<NUM>,<NUM>], [<NUM>, j,-<NUM>,-j], [<NUM>,-<NUM>,<NUM>,-<NUM>], [<NUM>,-j,-<NUM>,j]. In other words, the OCC (e.g., the OCCs <NUM> and/or <NUM>) can be a DFT sequence. Then, following the same FFT analysis and parallelism between the pre-DFT-OCC with DFT spreading and the FDM discussed above, it can be shown that the four UEs are frequency-division multiplexed every fourth subcarriers (e.g., the subcarriers <NUM>) and therefore the orthogonality between the UEs still holds regardless of the channel delay spread. Similar analysis may hold for other OCC spreading codes, for example, with a length of <NUM> or a length of <NUM>.

<FIG> and <FIG> collectively illustrate a scheme <NUM> for multiplexing multiple users on a DFT precoded frequency interlace. The scheme <NUM> may be employed by BSs such as the BSs <NUM> and <NUM> and UEs such as the UEs <NUM> and <NUM> in a network such as the network <NUM>. The scheme <NUM> is substantially similar to the scheme <NUM>. However, the scheme <NUM> multiplexes a UE A and a UE B on a same frequency interlace <NUM> including a set of distributed RBs <NUM>. The scheme <NUM> applies OCC block-spreading across the set of distributed RBs in the entire frequency interlace <NUM>. Similar to the scheme <NUM>, the UE A may be assigned with the OCC 710a represented by {C0 = <NUM>, C1 = <NUM>} and the UE B may be assigned with the OCC 710b represented by {C0 = <NUM>, C1 = -<NUM>}. Additionally, the scheme <NUM> is described using the frequency interlace structure in <FIG>, and may use the same reference numerals as in <FIG> for simplicity sake.

<FIG> illustrates a transmission scheme implemented by the UE A for multiplexing the UE A and the UE B on a DFT precoded interlace according to some embodiments of the disclosure. The UE A generates information symbols <NUM> shown as a0 to a59 (e.g., the information symbols <NUM>, <NUM>, and <NUM>). The UE A applies the OCC 710a to block-spread the information symbols <NUM> to form a sequence of block-spread symbols 912a. The block-spread symbols 912a, denoted as S<NUM>, is shown below: <MAT> The UE A applies a DFT <NUM> to the block-spread symbols 912a for a DFT spreading. The UE A performs a frequency interlace mapping <NUM> to map the DFT output 922a to a frequency interlace <NUM>I(<NUM>), for example, based on an allocation from the BS. Based on the FFT property analysis discussed above with respect to Equations (<NUM>) and (<NUM>), the DFT output 922a includes non-zero values in even tones (e.g., the subcarriers <NUM>) only. Subsequently, the UE A applies an IFFT <NUM> and a CP add operation <NUM> as in the scheme <NUM> to generate an output signal 944a for transmission.

<FIG> illustrates a transmission scheme implemented by the UE B for multiplexing the UE A and the UE B on a DFT precoded interlace according to some embodiments of the disclosure. The UE B generates information symbols <NUM> shown as b0 to b59 (e.g., the information symbols <NUM>, <NUM>, and <NUM>). The UE B applies the OCC 710b to block-spread the information symbols <NUM> to form a sequence of block-spread symbols 912b. The block-spread symbols 912b, denoted as S<NUM>, can be expressed as shown below: <MAT> The UE B performs DFT spreading to the block-spread symbols 912b by applying a DFT <NUM>. The UE B performs a frequency interlace mapping <NUM> to map the DFT output 922b to the same frequency interlace <NUM>I(<NUM>). Based on the FFT property analysis discussed above with respect to Equations (<NUM>) and (<NUM>), the DFT output 922b includes non-zero values in odd tones only. Subsequently, the UE B applies an IFFT <NUM> and CP add operation <NUM> generate an output signal 944b for transmission.

As discussed above, the pre-DFT-OCC spreading followed by the DFT spreading in the scheme <NUM> produce a similar orthogonal transmission structure among UEs as the FDM in the scheme <NUM>. Accordingly, the multiplexing of users or UEs on the DFT precoded frequency interlaces shown in <FIG> and <FIG> may have a substantially similar orthogonal transmission structure as the FDM-based frequency interlace mapping shown in <FIG> and <FIG>. For instances, UE A may transmit on even tones within RBs <NUM> of the frequency interlace <NUM>I(<NUM>) and UE B may transmit on odd tones within RBs <NUM> of the frequency interlace <NUM>I(<NUM>).

<FIG> illustrates a receive processing scheme <NUM> for a DFT precoded interlace according to some embodiments of the present disclosure. The scheme <NUM> may be employed by BSs such as the BSs <NUM> and <NUM> and UEs such as the UEs <NUM> and <NUM> in a network such as the network <NUM>. For example, the scheme <NUM> may be implemented by a receiver receiving a signal <NUM> transmitted by a transmitter on a frequency interlace (e.g., the frequency interlace <NUM>I(<NUM>)) using a pre-DFT-OCC as described in the scheme <NUM>. The scheme <NUM> includes a CP discard unit <NUM>, an FFT unit <NUM>, a frequency interlace demapper <NUM>, a subcarrier demapper <NUM>, an inverse DFT (IDFT) unit <NUM>, and a data recovery unit <NUM>.

The CP discard unit <NUM> is configured to remove or discard CPs from the received signal <NUM>. The FFT unit <NUM> is coupled to the CP discard unit <NUM> and configured to perform an FFT on the CP-discarded signal <NUM> to produce a frequency signal <NUM>. The frequency interlace demapper <NUM> is coupled to the FFT unit <NUM> and configured to extract the RBs (e.g., a set of distributed the RBs <NUM>) corresponding to the frequency interlace <NUM>I(<NUM>) from the frequency signal <NUM>. The frequency interlace demapper <NUM> produces a frequency signal <NUM>.

The subcarrier demapper <NUM> is coupled to the frequency interlace demapper <NUM> and configured to extract subcarriers (e.g., the subcarriers <NUM>) from the set of extracted RBs (e.g., the frequency signal <NUM>) based on the OCC that the transmitter used for the transmission of the received signal <NUM>. The extracted subcarriers form a frequency signal <NUM>. As an example, when the transmitter uses an OCC similar to the OCC 710a {<NUM>, <NUM>}, the subcarrier demapper <NUM> extracts the even subcarriers from the set of extracted RBs. In other words, the subcarrier demapper <NUM> forms a frequency signal <NUM> from the extracted even subcarriers. Alternatively, when the transmitter uses an OCC similar to the OCC 710b {<NUM>, -<NUM>}, the subcarrier demapper <NUM> extracts the odd subcarriers from the set of extracted RBs. In other words, the subcarrier demapper <NUM> forms a frequency signal <NUM> from the extracted odd subcarriers.

The IDFT unit <NUM> is coupled to the subcarrier demapper <NUM> and configured to perform an inverse DFT on the frequency signal <NUM> to produce a time signal <NUM>. The data recovery unit <NUM> is coupled to the IDFT unit <NUM> and configured to recovery the original information transmitted by the transmitter from the time signal <NUM>. The data recovery operations may include time and/or frequency equalization, demodulation, and/or decoding.

As can be observed, the subcarrier demapper <NUM> extracts the useful subcarriers corresponding to non-zero values of the DFT output (e.g., the DFT output 722a, 722b, 922a, and 922b) at the transmitter for data recovery processing and may discard or ignore other subcarriers corresponding to zero values (e.g., that does not carry useful information) of the DFT output at the transmitter.

In an implementation, the subcarrier demapper <NUM> may extract the useful tones and the DFT of size equal to the number of useful subcarriers is performed. In another implementation, the subcarrier demapper <NUM> may extract all tones of the interlace including non-useful subcarriers and OCC despreading may be performed at the data recovery unit <NUM> post DFT. The DFT size in this case equals to the number of subcarriers (useful + not useful) on the corresponding interlace.

<FIG> illustrates a user multiplexing scheme <NUM> that applies time-domain OCC across multiple SC-FDM symbols according to some embodiments of the present disclosure. In <FIG>, the x-axes represent time in some constant units and the y-axes represent frequency in some constant units. The scheme <NUM> may be employed by BSs such as the BSs <NUM> and <NUM> and UEs such as the UEs <NUM> and <NUM> in a network such as the network <NUM>. The scheme <NUM> can be used in conjunction with the scheme <NUM>. The scheme <NUM> can be applied after the scheme <NUM>. For example, a BS may further multiplex transmission of a UE A and a UE B by configuring the UE A and the UE B to perform time-domain spreading using an OCC 1110a and an OCC 1110b, respectively. For example, the OCC 1110a may be represented by {C0=<NUM>, C1=<NUM>} and the OCC 1110b may be represented by {C0=<NUM>, C1=-<NUM>}.

The UE A generates an output signal 1102a (e.g., an SC-FDM symbol) carrying information (e.g., the information symbols <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>) mapped to a certain frequency interlace (e.g., the frequency interlace <NUM>I(<NUM>)), for example, using the scheme <NUM>. The signal 1102a may correspond to the output signal 944a. The UE A applies the OCC 1110a to the signal 1102a to produce a time symbol 1112a(<NUM>) and a time symbol 1112a(<NUM>). For example, the UE A may multiply the signal 1102a by C0 of the OCC 1110a to produce the symbol 1112a(<NUM>) and multiply the signal 1102a by C1 of the OCC 1110a to produce the symbol 1112a(<NUM>). As shown in the plot <NUM>, the output signal 1102a is spread across two time symbols 1112a(<NUM>) and 1112a(<NUM>) (e.g., SC-FDM symbols) by the OCC 1110a.

The UE B generates an output signal 1102b (e.g., an SC-FDM symbol) carrying information (e.g., the information symbols <NUM>, 712a, 712b, 912a, and 912b) mapped to the same frequency interlace (e.g., the frequency interlace <NUM>I(<NUM>)) as the one used by the UE A, for example, using the scheme <NUM>. The signal 1102b may correspond to the output signal 944b. The UE B applies the OCC 1110b to the signal 1102b to produce a time symbol 1112b(<NUM>) and a time symbol 1112b(<NUM>). For example, the UE B multiplies the signal 1102b by C0 of the OCC 1110b to produce the symbol 1112b(<NUM>) and multiplies the signal 1102b by C1 of the OCC 1110b to produce the symbol 1112b(<NUM>). As shown in the plot <NUM>, the output signal 1102b is spread across two time symbols 1112b(<NUM>) and 1112b(<NUM>) by the OCC 1110b.

<FIG> illustrates a user multiplexing scheme <NUM> that applies code-hopping across SC-FDM symbols according to some embodiments of the present disclosure. In <FIG>, the x-axes represent time in some constant units and the y-axes represent frequency in some constant units. The scheme <NUM> may be employed by BSs such as the BSs <NUM> and <NUM> and UEs such as the UEs <NUM> and <NUM> in a network such as the network <NUM>. The scheme <NUM> employs substantially similar mechanisms as in the scheme <NUM>, but further applies code-hopping across multiple SC-FDM symbols. For example, a BS configures a UE A and a UE B to perform code-hopping in addition to pre-DFT-OCC spreading shown in the scheme <NUM>. The BS may configure the UE A with a code-hop pattern, where an OCC <NUM> is applied to a first symbol at time T0 and an OCC <NUM> is applied to a next symbol at time T1. The BS may configure the UE B with a code-hop pattern different than the UE A code-hop pattern, where the OCC <NUM> is applied to a first symbol at time T0 and the OCC <NUM> applied to a next symbol at time T1. The OCC <NUM> may be represented by {C0=<NUM>, C1=<NUM>} and the OCC <NUM> may be represented by {C0=<NUM>, C1=-<NUM>}.

The UE A hops from the OCC <NUM> to the OCC <NUM>. The UE A applies the OCC <NUM> to block-spread a block of information symbols <NUM> (e.g., the information symbols <NUM>, 702a, and 902a) to form block-spread information symbols 1212a using the same mechanisms as described in the scheme <NUM>. The UE A performs symbol generation <NUM> on the block-spread information symbols 1212a to form an output symbol 1232a. The symbol generation <NUM> may include processing of the DFT <NUM>, the frequency interlace mapping <NUM>, the IFFT <NUM>, and the CP add operation <NUM> in order.

Next, the UE A applies the OCC <NUM> to block-spread the information symbols <NUM> to form block-spread symbols 1222a. The UE A performs symbol generation <NUM> on the block-spread symbols 1222a to form an output symbol 1234a. As shown in the plot <NUM>, the UE A transmits the SC-FDM symbol 1232a at time T0 and the SC-FDM symbol 1234a at time T1, where code-hopping is applied across the symbols 1232a and 1234b.

The UE B hops from the OCC <NUM> to the OCC <NUM>. The UE B applies the OCC <NUM> to block-spread a block of information symbols <NUM> (e.g., the information symbols 702a and 902a) to form block-spread symbols 1222b. The UE B performs symbol generation <NUM> on the block-spread symbols 1222b to form an output symbol 1234b.

Next, the UE B applies the OCC <NUM> to block-spread the information symbols <NUM> to form block-spread information symbols 1212b. The UE B performs symbol generation <NUM> on the block-spread information symbols 1212b to form an output symbol 1232b. As shown in the plot <NUM>, the UE B transmits the SC-FDM symbol 1234b at time T0 and the SC-FDM symbol 1232b at time T1, where code-hopping is applied across the symbols 1234b and 1234a. As can be seen in the scheme <NUM>, the code-hopping is applied across SC-FDM symbols with no time-domain OCC applied across the SC-FDM symbols.

While the schemes <NUM>, <NUM>, <NUM>, and <NUM> are described in the context of multiplexing two UEs (e.g., a UE A and a UE B) on a frequency interlace (e.g., the frequency interlaces <NUM>) with OCCs (e.g., the OCCs 710a, 710b, 1110a, 1110b, and <NUM>, <NUM>) and of length <NUM>, the schemes <NUM>, <NUM>, <NUM>, <NUM> may be applied to multiplex any suitable number of UEs (e.g., about <NUM>, <NUM>, or <NUM>) on a frequency interlace and may vary the code length of the OCCs accordingly.

<FIG> is a flow diagram of a communication method <NUM> using a DFT precoded frequency interlace for transmissions according to some embodiments of the present disclosure. Steps of the method <NUM> can be executed by a computing device (e.g., a processor, processing circuit, and/or other suitable component) of a wireless communication device, such as the BS <NUM> and the BS <NUM>, may utilize one or more components, such as the processor <NUM>, the memory <NUM>, the pre-DFT-OCC-based communication module <NUM>, the transceiver <NUM>, and the one or more antennas <NUM>, to execute the steps of method <NUM>. In another example, a wireless communication device, such as the UE <NUM> and the UE <NUM>, may utilize one or more components, such as the processor <NUM>, the memory <NUM>, the pre-DFT-OCC-based communication module <NUM>, the transceiver <NUM>, and the one or more antennas <NUM>, to execute the steps of method <NUM>. The method <NUM> may employ similar mechanisms as in the schemes <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> described with respect to <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, respectively. As illustrated, the method <NUM> includes a number of enumerated steps, but embodiments of the method <NUM> may include additional steps before, after, and in between the enumerated steps. In some embodiments, one or more of the enumerated steps may be omitted or performed in a different order.

At step <NUM>, the method <NUM> includes identifying, by a first wireless communication device, a first block-spreading code from a set of block-spreading codes associated with user multiplexing. The set of block-spreading codes may be similar to the OCCs 710a and 710b or the OCCs <NUM> and <NUM>.

At step <NUM>, the method <NUM> includes communicating, by the first wireless communication device with a second wireless communication device using a frequency interlace (e.g., the frequency interlace <NUM>) in a frequency spectrum (e.g., the frequency spectrum <NUM>), a first communication signal (e.g., the output signals 944a and 944b and the time symbols 1112a, 1112b, 1232a, 1234a, 1232b, and 1234b) including a first block of information symbols (e.g., the information symbols <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) spread across a set of resource blocks (RBs) (e.g., the RBs <NUM>) within the frequency interlace based on the first block-spreading code. In some instances, the first block of information symbols are modulation symbols carrying UCI.

In an embodiment, the first wireless communication device may correspond to a BS and the second wireless communication device may correspond to a UE. In such an embodiment, the first wireless communication device may further transmit a configuration to the second wireless communication device indicating the identified first block-spreading code.

In an embodiment, the first wireless communication device may correspond to a UE and the second wireless communication device may correspond to a BS. In such an embodiment, the first wireless communication device may further receive a configuration from the second wireless communication device indicating the identified first block-spreading code. The first wireless communication may identify the first block-spreading code based on the received configuration.

In an embodiment, the first block of information symbols is carried by a first set of subcarriers (e.g., the subcarriers <NUM>) interlaced with a second set of subcarriers (e.g., the subcarriers <NUM>) in the set of RBs (e.g., the RBs <NUM>). For example, when the first block-spreading code is {<NUM>, <NUM>}, the first set of subcarriers may correspond to even subcarriers in the set of RBs. Alternatively, when the first block-spreading code is {<NUM>, <NUM>}, the first set of subcarriers may correspond to odd subcarriers in the set of RBs. In some other examples, the first block-spreading code may have a length of <NUM> or <NUM> and the first set of subcarriers may correspond to every fourth subcarrier or every sixth subcarrier, respectively, in the set of RBs.

In an embodiment, the first wireless communication device may communicate the first communication signal by transmitting, to the second wireless communication device, the first communication signal including the first block of information symbols carried by the first set of subcarriers.

In an embodiment, the first wireless communication device further generates the first communication signal by block-spreading the first block of information symbols based on the first block-spreading code to generate a first block of spread information symbols (e.g., the block-spread information symbols 912a, 912b, 1212a, 1212b, 1222a, and 1222b). After the block-spreading, the first wireless communication device performs a DFT (e.g., the DFTs <NUM> and <NUM>) on the first block of spread information symbols to generate a frequency signal (e.g., the DFT outputs 922a and 922b). After performing the DFT, the first wireless communication device maps the frequency signal to the set of resource blocks (e.g., the frequency interlace mapping <NUM>), wherein non-zero values of the frequency signal are located at the first set of subcarriers.

In an embodiment, the first block-spreading code includes at least a first code (e.g., C0 of the OCC 710a or 710b) and a second code (e.g., C1 of the OCC 710a or 710b). Each of the first code and the second code may be referred to as a code symbol. The first wireless communication device block-spreads the first block of information symbols by applying the first code to the first block of information symbols to generate a first block of coded information symbols and applying the second code to the first block of information symbols to generate a second block of coded information symbols. The first wireless communication device generates the first block of spread information symbols (e.g., the symbols 912a or 912b) based on at least the first block of coded information symbols and the second block of coded information symbols, for example, by concatenating the first and second blocks.

In an embodiment, the first wireless communication device may communicate the first communication signal by receiving, from the second wireless communication device, the first communication signal including the first block of information symbols carried by the first set of subcarriers. The first wireless communication device further performs an IDFT (e.g., the IDFT <NUM>) on the received first communication signal (e.g. the received signal <NUM>) based on the first set of subcarriers to recover the first block of information symbols, for example, using similar mechanisms as described in the scheme <NUM>.

In an embodiment, the first wireless communication device identifies a second block-spreading code from the set of block-spreading codes. The wireless communication device communicates, with a third wireless communication device different from the second wireless communication device, a second communication signal concurrent with the first communication signal, the second communication signal including a second block of information symbols spread across the frequency interlace based on the second block-spreading code. The second block of information symbols is carried by the second set of subcarriers. For example, the first wireless communication device corresponds to a BS, the second wireless communication device corresponds to a UE A, and the third wireless communication device corresponds to a UE B.

In an embodiment, the first communication signal is further communicated based on a time-domain spreading code (e.g., the OCCs 1110a and 1110b), for example, using the scheme <NUM>.

In an embodiment, the first wireless communication device identifies the first block-spreading code by applying a code-hopping pattern to the set of block-spreading codes, for example, using the scheme <NUM>.

Also, as used herein, including in the claims, "or" as used in a list of items (for example, a list of items prefaced by a phrase such as "at least one of" or "one or more of") indicates an inclusive list such that, for example, a list of [at least one of A, B, or C] means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

Further embodiments of the present disclosure include a method of wireless communication, comprising identifying, by a first wireless communication device, a first block-spreading code from a set of block-spreading codes associated with user multiplexing; and communicating, by the first wireless communication device with a second wireless communication device using a frequency interlace in a frequency spectrum, a first communication signal including a first block of information symbols spread across a set of resource blocks (RBs) within the frequency interlace based on the first block-spreading code.

In some embodiments, wherein the set of block-spreading codes includes orthogonal cover codes (OCCs). In some embodiments, wherein the first block of information symbols is carried by a first set of subcarriers interlaced with a second set of subcarriers in the set of RBs. In some embodiments, wherein the communicating includes transmitting, by the first wireless communication device to the second wireless communication device, the first communication signal including the first block of information symbols carried by the first set of subcarriers. In some embodiments, the method further comprises generating, by the first wireless communication device, the first communication signal by block-spreading the first block of information symbols based on the first block-spreading code to generate a first block of spread information symbols; performing a discrete Fourier transform (DFT) on the first block of spread information symbols to generate a frequency signal; and mapping the frequency signal to the set of RBs, wherein non-zero values of the frequency signal are located at the first set of subcarriers. In some embodiments, wherein the first block-spreading code includes at least a first code and a second code, and wherein the block-spreading the first block of information symbols includes applying the first code to the first block of information symbols to generate a first block of coded information symbols; applying the second code to the first block of information symbols to generate a second block of coded information symbols; and generating the first block of spread information symbols based on at least the first block of coded information symbols and the second block of coded information symbols. In some embodiments, wherein the communicating includes receiving, by the first wireless communication device from the second wireless communication device, the first communication signal including the first block of information symbols carried by the first set of subcarriers. In some embodiments, the method further comprises performing, by the first wireless communication device, an inverse discrete Fourier transform (IDFT) on the received first communication signal based on the first set of subcarriers to recover the first block of information symbols. In some embodiments, the method further comprises identifying, by the first wireless communication device, a second block-spreading code from the set of block-spreading codes; and communicating, by the first wireless communication device with a third wireless communication device, a second communication signal concurrent with the first communication signal, the second communication signal including a second block of information symbols spread across the frequency interlace based on the second block-spreading code, wherein the second block of information symbols is carried by the second set of subcarriers, and wherein the third wireless communication device is different from the second wireless communication device. In some embodiments, wherein the communicating is further based on a time-domain spreading code. In some embodiments, wherein the identifying includes applying, by the first wireless communication device, a code-hopping pattern to the set of block-spreading codes. In some embodiments, wherein the first block of information symbols are modulation symbols including uplink control channel information.

Further embodiments of the present disclosure include an apparatus comprising a processor configured to identify a first block-spreading code from a set of block-spreading codes associated with user multiplexing; and a transceiver configured to communicate, with a first wireless communication device using a frequency interlace in a frequency spectrum, a first communication signal including a first block of information symbols spread across a set of resource blocks (RBs) within the frequency interlace based on the first block-spreading code.

In some embodiments, wherein the set of block-spreading codes includes orthogonal cover codes (OCCs). In some embodiments, wherein the first block of information symbols is carried by a first set of subcarriers interlaced with a second set of subcarriers in the set of RBs. In some embodiments, wherein the transceiver is further configured to communicate the first communication signal by transmitting, to the first wireless communication device, the first communication signal including the first block of information symbols carried by the first set of subcarriers. In some embodiments, wherein the processor is further configured to generate the first communication signal by block-spreading the first block of information symbols based on the first block-spreading code to generate a first block of spread information symbols; performing a discrete Fourier Transform (DFT) on the first block of spread information symbols to generate a frequency signal; and mapping the frequency signal to the set of RBs, wherein non-zero values of the frequency signal are located at the first set of subcarriers. In some embodiments, wherein the first block-spreading code includes at least a first code and a second code, and wherein the processor is further configured to block-spread the first block of information symbols by applying the first code to the first block of information symbols to generate a first block of coded information symbols; applying the second code to the first block of information symbols to generate a second block of coded information symbols; and generating the first block of spread information symbols based on at least the first block of coded information symbols and the second block of coded information symbols. In some embodiments, wherein the transceiver is further configured to communicate the first communication signal by receiving, from the first wireless communication device, the first communication signal including the first block of information symbols carried by the first set of subcarriers. In some embodiments, wherein the processor is further configured to perform an inverse discrete Fourier transform (IDFT) on the received first communication signal based on the first set of subcarriers to recover the first block of information symbols. In some embodiments, wherein the processor is further configured to identify a second block-spreading code from the set of block-spreading codes, and the transceiver is further configured to communicate, with a second wireless communication device, a second communication signal concurrent with the first communication signal, the second communication signal including a second block of information symbols spread across the frequency interlace based on the second block-spreading code, wherein the second block of information symbols is carried by the second set of subcarriers, and wherein the second wireless communication device is different from the first wireless communication device. In some embodiments, wherein the first communication signal is further communicated based on a time-domain spreading code. In some embodiments, wherein the processor is further configured to identify the first block-spreading code by applying a code-hopping pattern to the set of block-spreading codes. In some embodiments, wherein the first block of information symbols are modulation symbols including uplink control channel information.

Further embodiments of the present disclosure include a computer-readable medium having program code recorded thereon, the program code comprising code for causing a first wireless communication device to identify a first block-spreading code from a set of block-spreading codes associated with user multiplexing; and code for causing the first wireless communication device to communicate, with a second wireless communication device using a frequency interlace in a frequency spectrum, a first communication signal including a first block of information symbols spread across a set of resource blocks (RBs) within the frequency interlace based on the first block-spreading code.

In some embodiments, wherein the set of block-spreading codes includes orthogonal cover codes (OCCs). In some embodiments, wherein the first block of information symbols is carried by a first set of subcarriers interlaced with a second set of subcarriers in the set of RBs. In some embodiments, wherein the code for causing the first wireless communication device to communicate first communication signal is further configured to transmit, to the second wireless communication device, the first communication signal including the first block of information symbols carried by the first set of subcarriers. In some embodiments, the computer-readable medium further comprises code for causing the first wireless communication device to generate the first communication signal by block-spreading the first block of information symbols based on the first block-spreading code to generate a first block of spread information symbols; performing a discrete Fourier transform (DFT) on the first block of spread information symbols to generate a frequency signal; and mapping the frequency signal to the set of RBs, wherein non-zero values of the frequency signal are located at the first set of subcarriers. In some embodiments, wherein the first block-spreading code includes at least a first code and a second code, and wherein the code for causing the first wireless communication device to block-spread the first block of information symbols is further configured to apply the first code to the first block of information symbols to generate a first block of coded information symbols; apply the second code to the first block of information symbols to generate a second block of coded information symbols; and generate the first block of spread information symbols based on at least the first block of coded information symbols and the second block of coded information symbols. In some embodiments, wherein the code for causing the first wireless communication device to communicate first communication signal is further configured to receive, rom the second wireless communication device, the first communication signal including the first block of information symbols carried by the first set of subcarriers. In some embodiments, the computer-readable medium further comprises code for causing the first wireless communication device to perform an inverse discrete Fourier transform (IDFT) on the received first communication signal based on the first set of subcarriers to recover the first block of information symbols. In some embodiments, the computer-readable medium further comprises code for causing the first wireless communication device to identify a second block-spreading code from the set of block-spreading codes; and code for causing the first wireless communication device to communicate, with a third wireless communication device, a second communication signal concurrent with the first communication signal, the second communication signal including a second block of information symbols spread across the frequency interlace based on the second block-spreading code, wherein the second block of information symbols is carried by the second set of subcarriers, and wherein the third wireless communication device is different from the second wireless communication device. In some embodiments, wherein the code for causing the first wireless communication device to communicate the first communication signal is further configured to communicate the first communication signal based on a time-domain spreading code. In some embodiments, wherein the code for causing the first wireless communication device to identify the first block-spreading code is further configured to apply a code-hopping pattern to the set of block-spreading codes. In some embodiments, wherein the first block of information symbols are modulation symbols including uplink control channel information.

Further embodiments of the present disclosure include an apparatus comprising means for identifying a first block-spreading code from a set of block-spreading codes associated with user multiplexing; and means for communicating, with a first wireless communication device using a frequency interlace in a frequency spectrum, a first communication signal including a first block of information symbols spread across a set of resource blocks (RBs) within the frequency interlace based on the first block-spreading code.

Claim 1:
A method (<NUM>) of wireless communication, comprising:
identifying (<NUM>), by a first wireless communication device, a first block-spreading code from a set of block-spreading codes associated with user multiplexing;
generating, by the first wireless communication device, a first communication signal by:
block-spreading a first block of information symbols based on the first block-spreading code to generate a first block of spread information symbols;
performing a discrete Fourier transform, DFT, on the first block of spread information symbols to generate a frequency signal; and
mapping the frequency signal to a set of resource blocks, RBs, wherein non-zero values of the frequency signal are located at a first set of subcarriers; and
communicating (<NUM>), by the first wireless communication device with a second wireless communication device using a frequency interlace in a frequency spectrum, wherein the frequency interlace includes a plurality of RBs evenly spaced over the frequency spectrum, wherein the first communication signal includes the first block of information symbols spread across the set of RBs within the frequency interlace based on the first block-spreading code, and wherein the first block of information symbols is carried by the first set of subcarriers interlaced with a second set of subcarriers in each RB of the set of RBs.