Patent Description:
This application relates to in-band full-duplex wireless communication and more particularly to hybrid same-frequency full-duplex (SFFD) and offset-frequency full-duplex (FD) wireless communication. SFFD refers to the use of the same frequency band for uplink and downlink transmission. Offset-frequency FD refers to the use of separate uplink and downlink frequency bands that are offset from each for uplink transmission and downlink transmission, respectively. Certain embodiments enable and provide solutions and techniques to improve communication between a base station (BS) and a cell-edge user equipment (UE).

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).

Since the wireless spectrum is not unlimited, users must limit their transmissions to regulated bandwidths. This bandwidth regulation also limits the achievable data rates because data rates are generally proportional to bandwidth as governed by Shannon's law. Despite these bandwidth limitations, modern communication standards are demanding ever greater data rates. For example, the fifth generation (<NUM>) wireless standard provides for data rates of up to <NUM> gigabits per second. To achieve such high data rates requires network users to efficiently use their available bandwidth. One way to enhance bandwidth usage is SFFD operation in which a transceiver transmits and receives data simultaneously over the same frequency band. But such in-band SFFD operation raises significant issues of self-interference. A cellular handset can only separate its transmitting and receiving antennas by a relatively short distance, so the transmitted signal may couple strongly into the received signal.

The patent application <CIT> relates to a system of operating a wireless device in a wireless communication network including selecting, by the wireless device, a preferred operating mode for use by the wireless device, the selection being made from at least a full duplex operating mode in which the wireless device can transmit and receive simultaneously on the same frequency band and a non full duplex operating mode; and transmitting a signal indicating the selected preferred operating mode to a network entity.

The self-interference for the received signal is inversely proportional to the separation in the operating wavelength between the transmitting and receiving antennas. In conventional communications standards such as the third generation (<NUM>), the licensed frequency bands were relatively low in frequency such that the separation in wavelengths is relatively small. But the licensed bands in the <NUM> standard include higher frequencies such that the antenna as measured by wavelengths is more pronounced. In addition, the antennas themselves are more compact for such higher frequencies such that a cellular handset can employ a transmitting array of antennas as well as a receiving array of antennas. This use of antennas arrays enables the handset (user equipment) to employ beamforming techniques that further limit the self-interference problem. The increased attenuation between the transmitting and receiving antennas and additional suppression through beamforming combined with analog and digital self-interference cancellation techniques makes the bandwidth efficiency of in-band SFFD operation an attractive option for <NUM> systems. But the implementation of in-band SFFD operation remains very challenging since it requires the handset to have approximately <NUM> decibels (dB) of isolation between the receiving and transmitting signal paths. As the isolation worsens, the self-leakage causes receiver de-sense that swamps the received signal.

One obstacle in realizing in-band SFFD operation is the size of the cell for each <NUM> base station. The pathloss at the higher <NUM> frequencies are significant such that power amplifier in the handset and in the base station needs to operate at a relatively high power as the handset moves to the periphery of the cell. Such high-power operation introduces distortion that increases the effective error vector magnitude (EVM) at the receiver even when a transmit signal at the receiver is sufficiently rejected. The resulting noise causes in-band SFFD operation problematic for <NUM> implementation. Such distortion could be reduced by decreasing the cell size. But such a decrease in cell size would be prohibitively expensive since it would require an inordinate number of base stations. Accordingly, there is a need in the art for improved in-band SFFD systems.

The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the disclosure and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. 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.

Embodiments of the present disclosure provide mechanisms for enabling in-band full-duplex operation without requiring excessively small cell size by segregating users in each cell into either an SFFD class or an offset-frequency FD class based upon pathlosses between the users and a serving base station (which is equivalent to segregating the users according to their power amplification levels). Users having relatively-low pathlosses are placed in the SFFD class, where each SFFD user's transmitter and receiver are allocated with the same frequency band within an allocated carrier-bandwidth. In other words, each SFFD user's transmitter and receiver are allocated with the same group of resource blocks within the allocated carrier-bandwidth. In contrast, users having relatively-high pathlosses are placed in the offset-frequency FD class, where each offset-frequency FD user's transmitter and receiver are allocated with dedicated receive and transmit frequency bands that are offset from each other but still within the allocated carrier-bandwidth. In other words, each offset-frequency FD user's transmitter and receiver are each allocated with a dedicated group of resource blocks within the carrier-bandwidth, where the allocated receive resource blocks and the allocated transmit resource blocks are offset from each other. Therefore, offset-frequency FD also operates in-band (within the allocated carrier-bandwidth) and in full-duplex as SFFD. The resulting access scheme may be designated as "hybrid" since it is a combination of both SFFD and offset-frequency FD operation, falling within the allocated carrier-bandwidth and supporting full-duplex operation.

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, Global System for Mobile Communications (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.

An OFDMA network may implement a radio technology such as evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) <NUM>, IEEE <NUM>, IEEE <NUM>, flash-OFDM and the like. UTRA, E-UTRA, and GSM are part of universal mobile telecommunication system (UMTS). 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the UMTS mobile phone standard.

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 a 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.

<NUM> NR also contemplates a self-contained integrated subframe design with UL/downlink scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive UL/downlink that may be flexibly configured on a per-cell basis to dynamically switch between UL and downlink to meet the current traffic needs.

In-band same-frequency full-duplex (SFFD) has double the capacity gain over half-duplex. However, as discussed above, SFFD can be challenging since it requires isolation in the order of about <NUM> decibel (dB) between a transmit signal path and a receive signal path. The current market solutions may allow SFFD operation at a limited coverage range. Thus, user equipment devices (UEs) located at a central region of a cell close to a serving base station (BS) may communicate with the BS using SFFD, whereas UEs located a cell edge or a periphery of the cell may not use SFFD for communication with the BS.

The present application describes mechanisms for enabling UEs in a cell to participate in full-duplex communication with a BS serving the cell irrespective of where the UEs are located within the cell. A BS selects between an SFFD mode and an offset-frequency full-duplex (FD) mode for communication with a UE based on a pathloss between the BS and the UE. An SFFD UE is allocated with a single, same frequency band within an allocated carrier-bandwidth (up to the entire allocated carrier-bandwidth) for simultaneous uplink (UL) transmission and downlink (DL) reception. In other words, the SFFD UE may be allocated with the same group of resource blocks for within the allocated carrier bandwidth for simultaneous UL transmission and DL reception. An offset-frequency FD UE is allocated with separate, dedicated transmit and receive frequency bands that are offset from each other within the carrier-bandwidth for simultaneous UL transmission and DL reception. In other words, the offset-frequency FD UE may be allocated with a dedicated group of resource blocks within the carrier-bandwidth for transmission and another dedicated group of resource blocks within the carrier-bandwidth for reception, where the group of transmit resource blocks are offset from the group of receive resource blocks. The present disclosure may use the term "transmit resource blocks" or "transmit frequency band" to refer to an UL transmit allocation and may use the term "receive resource blocks" or "receive frequency band" to refer to a DL receive allocation.

The BS may assign an SFFD mode to a UE with a relatively small pathloss between the BS and the UE, for example, when the pathloss is lower than a certain threshold. The BS may assign an offset-frequency FD mode to a UE with a relatively high pathloss between the BS and the UE, for example, when the pathloss is greater than a certain threshold. In some instances, the BS may serve the same data rate to UEs across a cell irrespective of whether the UE is configured for SFFD or offset-frequency FD communication. For instance, the BS may allocate a single <NUM> frequency band to an SFFD UE for simultaneous UL transmission and DL reception and may allocate a <NUM> UL transmit band and a separate <NUM> DL receive band for an offset-frequency FD UE. In some other instances, the BS may serve an SFFD UE with a higher data rate than an offset-frequency FD UE. For instance, the BS may allocate a single <NUM> frequency band to an SFFD UE for simultaneous UL transmission and DL reception and may allocate a <NUM> transmit band and a separate <NUM> receive band to an offset-frequency FD UE for simultaneous UL transmission and DL reception.

For offset-frequency FD operation, the UL transmit band and the DL receive band can be adjacent bands contiguous in frequency. Alternatively, the UL transmit band and DL receive band may be offset or spaced apart from each other. In some instances, the offset between a UL transmit band and a DL receive band may be dependent on a pathloss or a distance between the BS and a corresponding UE. In some instances, the UL transmit band and the DL receive band for one UE may interleave with a UL transmit band or a DL receive band of another UE. In some instances, an offset-frequency FD UE may perform an offset transmit modulation in a transmit path to allow for a single local oscillator (LO) to be used with a zero intermediate frequency (IF) conversion in a receive path.

<FIG> illustrates a wireless communication network <NUM> according to some aspects of the present disclosure. The network <NUM> may be a <NUM> network. The network <NUM> includes a number of base stations (BSs) <NUM> (individually labeled as 105a, 105b, 105c, 105d, 105e, and 105f) and other network entities. A BS <NUM> may be a station that communicates with UEs <NUM> and may also be referred to as an eNB, a 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>. The UEs 115i-<NUM> are examples of vehicles equipped with wireless communication devices 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 (DL) and/or uplink (UL), desired transmission between BSs <NUM>, backhaul transmissions between BSs, or sidelink transmissions between UEs <NUM>.

The BSs <NUM> may also communicate with a core network. The core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs <NUM> (e.g., which may be an example of a gNB or an access node controller (ANC)) may interface with the core network through backhaul links (e.g., NG-C, NG-U, etc.) and may perform radio configuration and scheduling for communication with the UEs <NUM>. In various examples, the BSs <NUM> may communicate, either directly or indirectly (e.g., through core network), with each other over backhaul links (e.g., X1, X2, etc.), which may be wired or wireless communication links.

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-step-size 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 asV2V, V2X, C-V2X communications between a UE 115i, 115j, or <NUM> and other UEs <NUM>, and/or vehicle-to-infrastructure (V2I) communications between a UE 115i, 115j, or <NUM> and a BS <NUM>.

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 some aspects, 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 or 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 aspects, 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 some aspects, 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 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 block (SSBs) over a physical broadcast channel (PBCH) and may broadcast the RMSI and/or the OSI over a physical downlink shared channel (PDSCH).

In some aspects, 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 PSS and the SSS may be located in a central region of a carrier or any suitable frequencies within the carrier.

After receiving the PSS and SSS, the UE <NUM> may receive a MIB, which may be transmitted in the physical broadcast channel (PBCH). 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, OSI, and/or one or more system information blocks (SIBs). 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 UL control channel (PUCCH), physical UL shared channel (PUSCH), power control, and SRS. In some aspects, SIB1 may contain cell access parameters and scheduling information for other SIBs.

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>. 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 scheduling grants may be transmitted in the form of DL control information (DCI). The BS <NUM> may transmit a DL communication signal (e.g., carrying data) to the UE <NUM> via a PDSCH according to a DL scheduling grant. The UE <NUM> may transmit an UL communication signal to the BS <NUM> via a PUSCH and/or PUCCH according to an UL scheduling grant. In some aspects, the BS <NUM> may communicate with a UE <NUM> using HARQ techniques to improve communication reliability, for example, to provide a URLLC service.

In some aspects, 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 aspects, 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.

To enable the UEs <NUM> in the network <NUM> to achieve the bandwidth efficiency of in-band FD operation, the pathloss between the BS <NUM> and each UE is estimated. The following description will assume that this estimation is made by a BS <NUM>, but it may also be performed by each UE <NUM>. In that regard, it is conventional for a BS <NUM> to estimate the pathloss, for example, such as through a signal-to-interference ratio (SIR) measurement and to command a UE <NUM> to transmit with a certain power amplification level accordingly. The power amplification level may thus be used as a proxy for the pathloss to segregate a UE <NUM> into either an SFFD class or an offset-frequency FD class. A UE <NUM> in the SFFD class functions using SFFD operation such that the UE <NUM>'s transmit frequency band is the same as the UE <NUM>'s receive frequency band. But UEs <NUM> in the offset-frequency FD class function using separate transmit and receive frequency bands. The offset-frequency FD class may thus also be denoted as a frequency division multiplexing (FDM) class.

In general, the UEs <NUM> operating in the periphery or the edge of a cell will need to employ a higher transmission power than the UEs <NUM> that are more centrally located or at a closer proximity to a BS <NUM>. The range to the BS <NUM> may thus also be used as a proxy for the pathloss to segregate the UEs <NUM> into either the SFFD class or the offset-frequency FD class. But note that a centrally-located UE <NUM> may also be in a high-path-loss environment such as when a structure obscures the line-of-sight between the UE <NUM> and the BS <NUM>. The distance between a UE <NUM> and the BS <NUM> may be one factor with regard to whether the UE <NUM> may function using SFFD or offset-frequency FD operation. Mechanisms for using SFFD and/or offset-frequency FD operation for communications between a BS <NUM> and a UE <NUM> are described in greater detail herein.

<FIG> illustrates transmit/receive paths of a UE <NUM> operating in an SFFD mode according to some aspects of the present disclosure. The UE <NUM> may correspond to a UE <NUM> in the network <NUM>. For instance, the UE <NUM> may be located centrally or close to a serving BS similar to the BS <NUM>. While <FIG> is described in the context of a UE, it will be appreciated that a BS may have analogous transmit and receive paths. <FIG> illustrates the transmit/receive paths of the UE <NUM> including a digital domain <NUM>, an analog domain <NUM>, and a propagation domain <NUM>.

In the digital domain <NUM>, the UE <NUM> may include a digital baseband portion (shown by the dashed box) including a coding/modulation component <NUM> in the transmit path, an interference cancellation component <NUM> and a demodulation/decoding component <NUM> in the receive path, and a control component <NUM>. The coding/modulation component <NUM>, the interference cancellation component <NUM>, the demodulation/decoding component <NUM>, the control component <NUM> may include hardware and/or software.

In the analog domain, the UE <NUM> may include a plurality of transmit chains <NUM> in the transmit path and a plurality of receive chains <NUM> in the receive path. Additionally, the transmit chains <NUM> are coupled to the receive chains <NUM> by a canceller circuit <NUM>. The transmit chains <NUM> are coupled to the coding/modulation component <NUM>. The receive chains <NUM> are coupled to the interference cancellation component <NUM> and the demodulation/decoding component <NUM>. For instance, the UE <NUM> may include N integer number of transmit chains <NUM> and N integer number of receive chains <NUM>. In some other instances, the UE <NUM> may include a greater number or a less number of transmit chains <NUM> than receive chains <NUM>. Each transmit chain <NUM> may include a digital-to-analog converter (DAC) <NUM>, a local oscillator (LO) <NUM>, a mixer <NUM>, and a power amplifier (PA) <NUM>. Each receive chain <NUM> may include a low-noise amplifier (LNA) <NUM>, a mixer <NUM>, a LO <NUM>, and an analog-to-digital converter (ADC) <NUM>.

For transmission, transmit (Tx) bits are processed in the digital domain <NUM>. In this regard, the transmit bits are coded and modulated by the coding/modulation component <NUM>. The resulting coded and modulated digital signals output by the coding/modulation component <NUM> drive the plurality of transmit chains <NUM> coupled to an array of N transmitting antennas <NUM>. Each transmit chain <NUM> passes through the analog domain <NUM> by being converted into analog form by the DAC <NUM> and then mixed with a LO <NUM> in a mixer <NUM> to produce an RF signal. The RF signal is amplified by the PA <NUM> (e.g., a high-power amplifier (HPA)) before driving the corresponding one of antennas <NUM> for transmission to a BS such as the BSs <NUM> along a transmission path <NUM>.

The receive chains <NUM> are analogous in that each receive chain <NUM> is coupled to a receiving antenna <NUM>. The resulting received RF signal passes through the analog domain <NUM> by being amplified by the LNA <NUM>, mixed with an LO <NUM> in a mixer <NUM> and converted into a digital form by the ADC <NUM>. The resulting digital received signals are demodulated and decoded by the demodulation/decoding component <NUM> in the digital domain <NUM> to form a stream of received bits.

As noted earlier, the isolation between the transmitted signal from transmitting antennas <NUM> and the desired received signal at receiving antennas <NUM> is to be substantially significant (e.g., approximately <NUM> decibel (dB)) to achieve a sufficient signal-to-noise ratio (SNR) in the receive path such that an acceptable or necessary bit error rate is obtained. A first step in satisfying this isolation is the physical separation between the transmitting antennas <NUM> and the receiving antennas <NUM>, for example, based on the layout of the antennas <NUM> and <NUM> at the UE <NUM>. In a typical UE or handset, this separation may be approximately <NUM> centimeters (cm). In the upper <NUM> frequency bands (e.g., at about <NUM> gigahertz (GHz)), such a separation provides approximately <NUM> dB of isolation over a direct transmission path <NUM>. In addition, beamforming and/or beam steering can be applied to the antennas <NUM> and <NUM> to provide approximately another <NUM> dB of isolation.

To achieve the desired <NUM> dB of isolation, the UE <NUM> utilizes the interference cancellation component <NUM> to perform digital interference cancellation in the digital domain <NUM>. For instance, the interference cancellation component <NUM> estimates the amount of interference in a received signal that is contributed by the transmit signal being coupled into the receive path. The interference cancellation component <NUM> may remove or reduce the interference from the received signal based on the estimation prior to demodulation and/or decoding. Additionally, the UE <NUM> utilizes the canceller circuit <NUM> in the analog domain <NUM> to provide analog interference cancellation. In some instances, the control component <NUM> can configure and/or control the canceller circuit <NUM> to provide the interference cancellation. This cancellation techniques further mitigate the interference from the direct transmission path <NUM> as well as reflections of the transmitted signal from nearby scatterers on reflected paths <NUM>. The combination of the analog and digital cancellation techniques provides another <NUM> dB of isolation in low-path-loss operation so that the desired level of <NUM> dB of overall isolation is satisfied. In such low-path-loss operation, the power amplification levels used by the transmitters or transmit chains <NUM> does not introduce a significant amount of distortion so that robust self-cancellation may be achieved to enable SFFD operation. As used herein, a pathloss that is relatively small (e.g., below a certain threshold) is deemed to be sufficient for supporting SFFD operation.

However, in a high-path-loss environment such as in the cell periphery or cell edge, the analog and digital self-interference cancellation techniques lose their effectiveness due to the elevated power amplification levels introducing distortion in the transmitted signals. Such a pathloss (e.g., greater that a certain threshold) is deemed herein to be insufficient for supporting SFFD operation. The resulting non-linearities can reduce the <NUM> dB of isolation for the cancellation techniques by <NUM> dB to <NUM> dB such that the desired level of <NUM> dB of isolation is not satisfied.

Accordingly, the present disclosure provides techniques for switching a UE from SFFD operation (using the same, single frequency band for transmit and receive) to offset-frequency FD operation (using different frequency bands for transmit and receive) based on whether pathlosses between the UE and the BS is sufficient for SFFD or not. For instance, the BS may use a pathloss threshold and/or a distance threshold to switch a UE between the SFFD operation and the offset-frequency FD operation. Mechanisms for provisioning hybrid SFFD and offset-frequency FD in a cell are described in greater detail herein.

<FIG> is a block diagram of an exemplary BS <NUM> according to some aspects of the present disclosure. The BS <NUM> may be a BS <NUM> discussed above in <FIG>. As shown, the BS <NUM> may include a processor <NUM>, a memory <NUM>, a FD 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 aspect, the memory <NUM> includes a non-transitory computer-readable medium. The memory <NUM> may store, or have recorded thereon, instructions <NUM>. 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 aspects of the present disclosure, for example, aspects of <FIG> and <FIG>. Instructions <NUM> may also be referred to as program code. The program code may be for causing a wireless communication device to perform these operations, for example by causing one or more processors (such as processor <NUM>) to control or command the wireless communication device to do so. 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 FD communication module <NUM> may be implemented via hardware, software, or combinations thereof. For example, the FD 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>. In some instances, the FD communication module <NUM> can be integrated within the modem subsystem <NUM>. For example, the FD communication module <NUM> can be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the modem subsystem <NUM>.

The FD communication module <NUM> may be used for various aspects of the present disclosure, for example, aspects of <FIG> and <FIG>. The FD communication module <NUM> is configured to determine a pathloss for a UE (e.g., the UEs <NUM> and/or <NUM>), select from an SFFD mode and an offset-frequency FD mode for communication with the UE based on the pathloss, allocate a same frequency band for the UE to transmit and receive if the SFFD is selected, allocate separate transmit and receive bands for the UE if offset-frequency FD is selected, determine a frequency offset or frequency spacing between the transmit and receive bands (e.g., based on the pathloss) if the offset-frequency FD is selected, and transmit an indication of a transmit-receive frequency band allocation to the UE based on the allocation. When SFFD is selected, the FD communication module <NUM> is configured to transmit data to the UE in a frequency band while receiving data from the UE in the same frequency band for the SFFD operation. When offset-frequency FD is selected, the FD communication module <NUM> is configured to transmit data to the UE in a second frequency band while receiving data from the UE in a third frequency band distinct from the second frequency band for the offset-frequency FD operation.

In some instances, the FD communication module <NUM> is configured to receive reference signals from the UE, transmit reference signals to the UE, estimate a pathloss or distance between the BS <NUM> and the UE based on received reference signals, report the pathloss or distance estimate, transmit a transmit power control command to the UE, configure the transceiver <NUM> based on the transmit power control command. In some instances, the FD communication module <NUM> is configured to perform interference cancellation, for example, by coordinating with the transceiver <NUM>. Mechanisms for segregating UEs in a cell into an SFFD class and an offset-frequency FD class for full-duplex communications are 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 FD 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 (e.g., PDSCH, PDCCH, transmit-receive frequency band allocations, for SFFD and/or offset-frequency FD communications, reference signals for pathloss measurements, transmit power control commands) from the modem subsystem <NUM> (on outbound transmissions) or of transmissions originating from another source such as a UE <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 transceiver <NUM> may provide the demodulated and decoded data (e.g., PUCCH, PUSCH, reference signals for pathloss measurement) to the FD communication module <NUM> for processing. 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>.

In an aspect, the transceiver <NUM> is configured to transmit data to the UE over a first frequency band while receiving second data from the UE over the first frequency band responsive to a pathloss between the BS and the UE satisfying a threshold for an SFFD operation, for example, by coordinating with the FD communication module <NUM>. In an aspect, the transceiver <NUM> is configured to transmit data to the UE over a second frequency band while receiving data from the UE over a third frequency band that is distinct from the second frequency band according to an offset-frequency FD operation, for example, by coordinating with the FD communication module <NUM>.

In an aspect, the BS <NUM> can include multiple transceivers <NUM> implementing different RATs (e.g., NR and LTE). In an aspect, the BS <NUM> can include a single transceiver <NUM> implementing multiple RATs (e.g., NR and LTE). In an aspect, the transceiver <NUM> can include various components, where different combinations of components can implement different RATs.

<FIG> is a block diagram of an exemplary UE <NUM> according to some aspects of the present disclosure. The UE <NUM> may be a UE <NUM> in the network <NUM> as discussed above in <FIG>. A shown, the UE <NUM> may include a processor <NUM>, a memory <NUM>, a FD 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.

In some aspects, the memory <NUM> may include 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 operations described herein, for example, aspects of <FIG> and <FIG>.

The FD communication module <NUM> may be used for various aspects of the present disclosure, for example, aspects of <FIG> and <FIG>. The FD communication module <NUM> is configured to receive a transmit-receive frequency band allocation from a BS (e.g., the BSs <NUM> and/or <NUM>) and communicate with the BS based on the transmit-receive frequency band allocation. The transmit-receive frequency band allocation may be configured for SFFD or offset-frequency FD communication with the BS depending on a pathloss between the UE <NUM> and the BS. When the transmit-receive frequency band allocation indicates a single, same first frequency band for SFFD, the FD communication module <NUM> is configured to transmit data to the BS in the first frequency band while receiving data from the BS in the same first frequency band for the SFFD operation. When the transmit-receive frequency band allocation indicates a second frequency band and a separate third frequency band for offset-frequency FD, the FD communication module <NUM> is configured to transmit data to the BS in the second frequency band while receiving data from the UE in the third frequency band for the offset-frequency FD operation. In some instances, the second frequency band and the third frequency band are adjacent frequency bands. In some instances, the second frequency band and the third frequency band are spaced apart from each other by a guard band or a frequency separation. In some instances, the frequency separation between the second frequency band and the third frequency band are dependent on a pathloss or distance between the UE <NUM> and the BS.

In some instances, the FD communication module <NUM> is configured to receive reference signals from the BS, transmit reference signals to the BS, estimate a pathloss or distance between the UE <NUM> and the BS based on received reference signals, report the pathloss or distance estimate, receive a transmit power control command from the BS, configure the transceiver <NUM> based on the transmit power control command. In some instances, the FD communication module <NUM> is configured to perform interference cancellation, for example, by coordinating with the transceiver <NUM>. Mechanisms for SFFD communications and offset-frequency FD communications with a BS are described in greater detail herein.

As shown, the transceiver <NUM> may include the modem subsystem <NUM> and the RF unit <NUM>. The modem subsystem <NUM> may be similar to the baseband portion of the UE <NUM> shown in <FIG>. The RF unit <NUM> may be substantially similar to the transmit chains <NUM> and the receive chains <NUM> of the UE <NUM>. The transceiver <NUM> can be configured to communicate bi-directionally with other devices, such as the UEs <NUM> and/or <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 (e.g., PUSCH, PUCCH, reference signals for pathloss measurement, and/or pathloss and/or distance estimates) from the modem subsystem <NUM> (on outbound transmissions) or of transmissions originating from another source such as a UE <NUM>, a BS <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/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 some aspects 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 transceiver <NUM> may provide the demodulated and decoded data (e.g., PDSCH, PDCCH, transmit-receive frequency band allocation for SFFD or offset-frequency FD communication) to the FD communication module <NUM> for processing. The antennas <NUM> may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

In an aspect, the transceiver <NUM> is configured to transmit data to the BS over a first frequency band while receiving second data from the BS over the first frequency band responsive to a pathloss between the BS and the UE satisfying a threshold for an SFFD operation, for example, by coordinating with the FD communication module <NUM>. In an aspect, the transceiver <NUM> is configured to transmit data to the BS over a second frequency band while receiving data from the BS over a third frequency band that is distinct from the second frequency band according to an offset-frequency FD operation, for example, by coordinating with the FD communication module <NUM>.

In an aspect, the UE <NUM> can include multiple transceivers <NUM> implementing different RATs (e.g., NR and LTE). In an aspect, the UE <NUM> can include a single transceiver <NUM> implementing multiple RATs (e.g., NR and LTE). In an aspect, the transceiver <NUM> can include various components, where different combinations of components can implement different RATs.

<FIG>, <FIG>, and <FIG> illustrate various mechanisms for operating a cell in a hybrid mode where UEs (e.g., the UEs <NUM> and <NUM>) at a central region of the cell may communicate with a BS using SFFD and UEs at a cell edge or cell periphery may communicate with a BS using offset-frequency FD. In <FIG>, <FIG>, and/or 7A, the cells <NUM>, <NUM>, and/or <NUM> may correspond to a portion of the network <NUM>. Additionally, in <FIG>, <FIG>, and <FIG>, the x-axes may represent frequency some arbitrary units, and the y-axes may represent power in some arbitrary units.

<FIG> illustrates a hybrid cell <NUM> having users segregated into a central SFFD portion and an outer offset-frequency FD portion according to some aspects of the present disclosure. The cell <NUM> includes a central region <NUM> and a peripheral region <NUM>. <FIG> illustrates a transmit/receive frequency band allocation for an SFFD user according to some aspects of the present disclosure. <FIG> illustrates a transmit/receive frequency band allocation for an offset-frequency FD user according to some aspects of the present disclosure. <FIG> illustrates one BS <NUM> serving one UE 515a in the central region <NUM> and one UE 515b in the peripheral region <NUM> for purposes of simplicity of discussion, though it will be recognized that embodiments of the present disclosure may scale to any suitable number of UEs in the central region <NUM> (e.g., <NUM>, <NUM>, <NUM>, or <NUM> or more) and any suitable number of UEs in the peripheral region <NUM> (e.g., <NUM>, <NUM>, <NUM>, or <NUM> or more). The BS <NUM> is similar to the BS s <NUM> and/or <NUM>. The UEs <NUM> are similar to the UEs <NUM> and/or <NUM>.

In the central region <NUM> of the cell <NUM>, each UE may communicate with the BS <NUM> using an SFFD mode. In this regard, the UE may use the same frequency band for transmission and reception simultaneously. As shown in <FIG>, the BS <NUM> allocates a single, same UL/DL frequency band <NUM> within an allocated carrier-bandwidth <NUM> to the UE 515a located at the central region <NUM> of the cell <NUM> for SFDD communication over the communication link 520a. In other words, the BS <NUM> may allocate the same group of resource blocks occupying the frequency band <NUM> for the UE 515a to transmit and receive. Accordingly, the UE 515a's may simultaneously transmit in the frequency band <NUM> (shown by the transmit (Tx) spectrum <NUM> in solid line) and receive in the frequency band <NUM> (shown by the receive (Rx) spectrum <NUM> in dotted line). The carrier-bandwidth <NUM> may be located at any suitable frequency and may occupy any suitable amount of frequency. The carrier-bandwidth <NUM> may refer to the available channel bandwidth at an RF carrier. In some instance, the carrier-bandwidth <NUM> may be at a mmWav frequency and may occupy about <NUM> megahertz (MHz), <NUM> gigahertz (GHz) or more. In an example, the carrier-bandwidth <NUM> available to be shared by UEs in the central region <NUM> may be about <NUM> wide. Each SFFD UE (e.g., the UE 515a) may be assigned its own <NUM> slot within the <NUM> bandwidth. The transmission band and receive band for an SFFD UE would thus be the same <NUM> slot assigned to the SFFD UE.

A UE in the peripheral region <NUM> of cell <NUM> may use a high power amplification (in the transmit and receive paths) to communicate with the BS <NUM> due to the high path-loss. The high power amplification levels may introduce too much distortion for SFFD operation. As such, UEs in the cell edge or peripheral region <NUM> may communicate with the BS <NUM> using offset-frequency FD. In this regard, a cell-edge UE may transmit and receive using different frequency bands. As shown in <FIG>, the BS <NUM> allocates a transmit frequency band <NUM> and a separate receive frequency band <NUM> in the carrier-bandwidth <NUM> to the UE 515b located in the peripheral region <NUM> of the cell <NUM> for offset-frequency FD communication over the communication link 520b. In other words, the BS <NUM> may allocate a first group of resource blocks occupying the frequency band <NUM> and a separate second group of resource blocks occupying the frequency band <NUM> for the UE 515b to transmit and receive, respectively. Accordingly, the UE 515b's may simultaneously transmit in the frequency band <NUM> (shown by the transmit (Tx) spectrum <NUM> in solid line) and receive in the separate frequency band <NUM> (shown by the receive (Rx) spectrum <NUM> in dotted line). As can be observed, the UE 515b's receive operates at a first sidelobe <NUM> of the UE 515b's transmit. The shifting or offsetting the UE 515b's receive to operate in the first sidelobe <NUM> of the transmit can provide about <NUM> dB of isolation between the transmit and receive. Accordingly, each UE <NUM> in the cell <NUM> is configured for hybrid operation that is either SFFD or offset-frequency FD depending upon its power amplification levels and the pathlosses between the UE and the BS <NUM>.

The frequency bands <NUM>, <NUM>, and <NUM> can be located in any suitable frequency. In some instances, the cell <NUM> is a <NUM> cell and the frequency bands <NUM>, <NUM>, and <NUM> may include sub-<NUM> bands and/or mmWave bands.

In some aspects, the same data rate may be applied to UEs across the cell <NUM>. In this regard, offset-frequency FD UEs at the peripheral region <NUM> are allocated with transmit and receive bands having the same bandwidth as the shared band for the SFFD UEs at the central region <NUM>. For example, if each SFFD UE is assigned its own <NUM> band that is shared for transmission and reception, then the transmit and receive bands for the offset-frequency FD UEs would each be <NUM> to provide the same data rate (assuming the modulation and coding provides for such equality). In the illustrated example of <FIG>, the BS <NUM> may allocate <NUM> for the single frequency band <NUM> assigned to the SFFD UE 515a for transmit and receive and may allocate <NUM> for each frequency band <NUM> and <NUM> assigned to the offset-frequency FD UE 515b for transmit and receive, respectively.

Alternatively, the data rates and/or bandwidths may be different for UEs in the region <NUM> and UEs in the region <NUM>. In this regard, UEs located at the central region <NUM> may be allocated with a wider bandwidth for a higher throughput or data rate than UEs located at the peripheral region <NUM>. For instance, the BS <NUM> may allocate <NUM> for the single frequency band <NUM> assigned to the SFFD UE 515a and may allocate <NUM> for each frequency band <NUM> and <NUM> assigned to the offset-frequency FD UE 515b for transmit and receive, respectively.

While <FIG> illustrates the separate transmit and receive frequency bands for offset-frequency FD operation to be contiguous in frequency, the separate transmit and receive frequency bands can be offset or spaced apart from each other as shown in <FIG> and <FIG> below.

<FIG> illustrates a hybrid cell <NUM> having users segregated into a central SFFD portion and an outer offset-frequency FD portion according to some aspects of the present disclosure. <FIG> illustrates a transmit/receive frequency band allocation for an SFFD user according to some aspects of the present disclosure. <FIG> illustrates a transmit/receive frequency band allocation for an offset-frequency FD user according to some aspects of the present disclosure. Generally speaking, the cell <NUM> includes features similar to cell <NUM> of <FIG> in many respects. For instance, the cell <NUM> includes a central region <NUM> and a peripheral region <NUM>, where a BS <NUM> may configure a UE 615a located at the central region <NUM> for SFFD communication and may configure a UE 615b located at the peripheral region for offset SFFD communication. The BS <NUM> is similar to the BSs <NUM>, <NUM>, and/or <NUM>. The UEs <NUM> are similar to the UEs <NUM>, <NUM>, <NUM>, and/or <NUM>. As shown in <FIG>, the BS <NUM> allocates a single frequency band <NUM> in a carrier-bandwidth <NUM> (e.g., the carrier-bandwidth <NUM>) to the UE 615a located at the central region <NUM> for SFDD communication over the communication link 620a. The BS <NUM> may allocate the same group of resource blocks occupying the frequency band <NUM> for the UE to transmit and receive. The UE 615a may simultaneously transmit in the frequency band <NUM> (shown by the transmit spectrum <NUM> in solid line) and receive in the frequency band <NUM> (shown by the receive spectrum <NUM> in dotted line).

However, in the cell <NUM>, each UE located at the peripheral region <NUM> is assigned with a transmit band spaced apart from a receive band by one or more bands for offset-frequency FD. In other words, offset-frequency FD UEs are assigned with transmit and receive bands that are non-contiguous in frequency. As shown in <FIG>, the BS <NUM> allocates a transmit frequency band <NUM> and a separate receive frequency band <NUM> to the UE 615b located in the peripheral region <NUM> for offset-frequency FD communication over the communication link 620b, where the transmit frequency band <NUM> is spaced apart from the receive frequency band <NUM> by a frequency separation <NUM>. In other words, the BS <NUM> may allocate a group of resource blocks occupying the frequency band <NUM> and a group of resource blocks occupying the frequency band <NUM> for the UE 615b to transmit and receive, respectively. The UE 615b may simultaneously transmit in the frequency band <NUM> (shown by the transmit (Tx) spectrum <NUM> in solid line) and receive in the separate frequency band <NUM> (shown by the receive (Rx) spectrum <NUM> in dotted line). As can be observed, the UE 615b's receive operates at a second sidelobe <NUM> of the UE 615b's transmit. The frequency separation <NUM> allows the UE 615b's receive to operate in the second sidelobe <NUM> of the transmit rather than the first sidelobe <NUM> of the transmit as in <FIG>. Thus, the frequency separation <NUM> can provide additional rejection (e.g., > <NUM> dB) between the transmit and receive channels. In general, the higher the frequency separation <NUM> between the transmit band <NUM> and the receive band <NUM>, the lower the transmit emission into the receiver.

In some aspects, SFFD UEs located at the central region <NUM> may be allocated with a wider bandwidth for a higher data rate than offset-frequency FD UEs located at the peripheral region <NUM>. Additionally, the frequency separation between the transmit and receive bands assigned to an offset-frequency FD UE may be based on the pathloss and/or distance between the offset-frequency FD UE and the BS. For instance, the BS <NUM> may allocate about <NUM> for the single frequency band <NUM> assigned to the SFFD UE 615a and may allocate <NUM> for each frequency band <NUM> and <NUM> assigned to the offset-frequency FD UE 615b for transmit and receive, respectively. The BS <NUM> may determine the frequency separation <NUM> based on the pathloss between the UE 615b and the BS <NUM>.

In some aspects, the BS <NUM> may determine a distance between the UE 615b and the BS <NUM> based on pathloss measurement for the UE 615b. The BS <NUM> may store a look-up-table (LUT), for example, in a memory such as the memory <NUM>, that maps frequency separations to distances. As the distance increases, the interference from the transmit to the receive may increase. Thus, in some instances, the frequency separation may increase as the distance increases to provide better rejection between the transmit and receive channels. For instance, the BS <NUM> may obtain an estimate of a distance between the UE 615b and the BS <NUM>. The BS <NUM> may determine a frequency separation <NUM> for transmit and receive frequency band allocation for the UE 615b based on the LUT.

<FIG> illustrates a hybrid cell <NUM> having users segregated into a central SFFD portion and an outer offset-frequency FD portion according to some aspects of the present disclosure. <FIG> illustrates a transmit/receive frequency band allocation for an SFFD user according to some aspects of the present disclosure. <FIG> illustrates transmit/receive frequency band allocation for an offset-frequency FD user according to some aspects of the present disclosure. Generally speaking, the cell <NUM> includes features similar to cell <NUM> of <FIG> and the cell <NUM> of <FIG> in many respects. For instance, the cell <NUM> includes a central region <NUM> and a peripheral region <NUM>, where a BS <NUM> may configure a UE 715a located at the central region <NUM> for SFFD communication and may configure a UE 715b and a UE 715c located at the peripheral region for offset SFFD communication. The BS <NUM> is similar to the BSs <NUM>, <NUM>, <NUM>, and/or <NUM>. The UEs <NUM> are similar to the UEs <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>. As shown in <FIG>, the BS <NUM> allocates a single frequency band <NUM> in an allocated carrier-bandwidth <NUM> (e.g., the carrier-bandwidths <NUM> and <NUM>) to the UE 715a located at the central region <NUM> for SFDD communication over the communication link 720a. The UE 715a may simultaneously transmit in the frequency band <NUM> (shown by the transmit spectrum <NUM> in solid line) and receive in the frequency band <NUM> (shown by the receive spectrum <NUM> in dotted line).

Further, similar to the cell <NUM>, each UE located at the peripheral region <NUM> is assigned with a transmit band spaced apart from a receive band by one or more bands for offset-frequency FD. However, in the cell <NUM>, an offset-frequency FD UE at the peripheral region <NUM> may be assigned with transmit and receive bands that are separated by a transmit band or a receive band of another offset-frequency FD UE at the peripheral region <NUM>. As shown in <FIG>, the BS <NUM> allocates a transmit frequency band <NUM> and a separate receive frequency band <NUM> to the UE 715b located in the peripheral region <NUM> for offset-frequency FD communication over the communication link 720b. In other words, the BS <NUM> may allocate a group of resource blocks occupying the frequency band <NUM> and another group of resource blocks occupying the frequency band <NUM> for the UE 715b to transmit and receive, respectively. The BS <NUM> further allocates a transmit frequency band <NUM> and a separate receive frequency band <NUM> to the UE <NUM> located in the peripheral region <NUM> for offset-frequency FD communication over the communication link 720c. In other words, the BS <NUM> may allocate a group of resource blocks occupying the frequency band <NUM> and another group of resource blocks occupying the frequency band <NUM> for the UE 615c to transmit and receive, respectively. The allocation to the UE 715b interleaves with the allocation to the UE 715c such that the transmit frequency bands <NUM> and the receive frequency band <NUM> of the UE 715b are spaced apart by the transmit frequency band <NUM> of the UE 715c. The UE 715b may simultaneously transmit in the frequency band <NUM> (shown by the transmit (Tx) spectrum <NUM> in solid line) and receive in the separate frequency band <NUM> (shown by the receive (Rx) spectrum <NUM> in solid line). The UE 715c may simultaneously transmit in the frequency band <NUM> (shown by the transmit (Tx) spectrum <NUM> in dotted line) and receive in the separate frequency band <NUM> (shown by the receive (Rx) spectrum <NUM> in dotted line). The simultaneous transmission and reception of the UE 715b may occur at the same time as the simultaneous transmission and reception of the UE 715c.

Depending on the separation between the UE 715b and the UE 715c in the peripheral region <NUM>, the amount of transmit signal from the UE 715c leaked into the receive band <NUM> of the UE 715b may be minimal. For instance, when the UE 715c is about one meter away from the UE 715b, the transmit noise from the UE 715c leaked into the receive band <NUM> of the UE 715b may be attenuated by about <NUM> dB.

In some aspects, the UE 715b and/or the UE 715c may utilize an analog baseband filter at the receiver (e.g., the receive chain <NUM>) prior to an ADC (e.g., the ADC <NUM>) to reject the transmit signal of the UE 715b and/or the transmit signal of the nearby UE 715c that are leaked into the UE 715b's receiver. The analog baseband filter at the UE 715b's receiver may have a filter with a frequency response <NUM> as shown in <FIG>. Similar analog baseband filter may also be used by the UE <NUM> of <FIG> with the contiguous transmit/receive allocation and/or the UE <NUM> of <FIG> with the spaced apart transmit/receive allocation.

In some aspects, a BS (e.g., the BSs <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>) may utilize SFFD for communications with UEs (e.g., the UEs <NUM>, <NUM>, 515a, 615a, and/or 715a) located in a central region (e.g., the central region <NUM>, <NUM>, and/or <NUM>) of a cell (e.g., the cells <NUM>, <NUM>, and/or <NUM>) up to a periphery of the cell. The BS may utilize offset-frequency FD for communications with UEs located at a cell edge (e.g., the outer peripheral region <NUM>, <NUM>, and/or <NUM>) by allocated separate transmit and receive bands for the UEs, where the separate transmit and receive bands may be contiguous in frequency as shown in <FIG>, spaced apart in frequency as shown in <FIG>, and/or interleaved with another UE's transmit and/or receive band as shown in <FIG>. The BS may select between the SFFD and the offset-frequency FD based on a pathloss between the BS and a corresponding UE. For instance, the BS may configure a UE in a cell range that can achieve about <NUM> dB transmit-receive isolation for SFFD and may configure a UE in at a cell edge with consecutive transmit-receive band allocation or spaced apart transmit-receive band allocation to achieve <NUM> dB or more transmit-receive isolation.

Regardless of whether the transmit and receive bands are contiguous or separated, an advantageous frequency offset at baseband may be used in an UE operating with SFFD. <FIG> illustrates transmit/receive paths of a UE <NUM> operating in an offset-frequency FD mode according to some aspects of the present disclosure. The UE <NUM> may correspond to a UE <NUM> in the network <NUM>, the cell-edge UE 515b in the cell <NUM>, the cell-edge UE 615b in the cell <NUM>, the cell-edge UE 715b or 715c in the cell <NUM>. The UE <NUM> may have a substantial similar baseband portion and/or transmit/receive chains as the UE <NUM>. <FIG> illustrates a portion of the analog transmit/receive paths of the UE <NUM>. Additionally, <FIG> illustrates a receiver configuration that combines an offset transmit modulation with a zero-intermediate frequency (IF) receive conversion to enable the use of a single LO for direct RF to direct-current (DC) conversion in the receive path.

The UE <NUM> includes a mixer <NUM> coupled to a PA <NUM> in the transmit path, a mixer <NUM> coupled to a LNA <NUM> in the receive path, a LO <NUM> coupled to the mixer <NUM> and the mixer <NUM>, and an analog baseband lowpass filter <NUM> coupled to the mixer <NUM>. The mixer <NUM>, the PA <NUM>, the mixer <NUM>, the LNA <NUM>, and the LO <NUM> may be substantially similar to the mixer <NUM>, the PA <NUM>, the mixer <NUM>, the LNA <NUM>, and the LOs <NUM> and <NUM> of the UE <NUM> shown in <FIG>, respectively.

As shown in <FIG>, the analog baseband signal <NUM> for the transmit path is offset in frequency from the baseband DC frequency by an offset <NUM> (e.g., about <NUM>). After mixing with the LO <NUM> by the mixer <NUM> and amplification by the PA <NUM>, the transmit band for the transmitted RF signal <NUM> is thus <NUM> higher than the LO frequency as shown by the offset <NUM>. In contrast, the receive band <NUM> is centered about the LO due to the frequency offset between the transmit and receive bands. The transmitted RF signal <NUM> that is coupled to the receive path at the input to the LNA <NUM> is shown as 804a. After amplification by the LNA <NUM> and mixing with the LO <NUM> by the mixer <NUM> for a downconversion, the received signal <NUM> at the baseband will thus be centered around the baseband DC frequency whereas the leakage from the transmitted signal (shown as <NUM>) into the received signal <NUM> at the baseband is greater than DC by the <NUM> offset. The leakage is thus readily filtered by the lowpass filter <NUM>.

<FIG> is a flow diagram of a communication method <NUM> according to some aspects of the present disclosure. Blocks 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 or other suitable means for performing the blocks. For example, a wireless communication device, such as the UEs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>, may utilize one or more components, such as the processor <NUM>, the memory <NUM>, the FD communication module <NUM>, the transceiver <NUM>, the modem <NUM>, and the one or more antennas <NUM>, to execute the blocks of method <NUM>. The method <NUM> may employ similar SFFD and offset-frequency FD allocation mechanisms discussed above with respect to <FIG> and <FIG>. As illustrated, the method <NUM> includes a number of enumerated blocks, but aspects of the method <NUM> may include additional blocks before, after, and in between the enumerated blocks. In some aspects, one or more of the enumerated blocks may be omitted or performed in a different order.

At block <NUM>, responsive to a first pathloss between a UE and a BS satisfying a threshold for an SFFD operation, the UE transmits first data to the BS over a first frequency band while receiving second data from the BS over the first frequency band. The UE may be similar to the UEs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>. The BS may be similar to the BSs <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>. In some instances, the UE may utilize one or more components, such as the processor <NUM>, the FD communication module <NUM>, the transceiver <NUM>, the modem <NUM>, and the one or more antennas <NUM>, to transmit the first data to the BS over the first frequency band while receiving the second data from the BS over the first frequency band. The UE may transmit the first data to the BS using a group of resource blocks occupying the first frequency band in a carrier-bandwidth (e.g., the carrier-bandwidths <NUM>, <NUM>, and/or <NUM>) while receiving the second data from the BS in the same group of resource blocks occupying the first frequency band.

At block <NUM>, responsive to a second pathloss between the UE and the BS failing to satisfy the threshold, the UE transmits third data to the BS over a second frequency band while receiving fourth data from the BS over a third frequency band that is distinct from the second frequency band according to an offset-frequency FD operation. In some instances, the UE may utilize one or more components, such as the processor <NUM>, the FD communication module <NUM>, the transceiver <NUM>, the modem <NUM>, and the one or more antennas <NUM>, to transmit the third data to the BS over the second frequency band while receiving the fourth data from the BS over the third frequency band. The UE may transmit the third data to the BS using a group of resource blocks occupying the second frequency band in the carrier-bandwidth while receiving the fourth data from the BS in a group of resource blocks occupying the third frequency band in the carrier-bandwidth.

In some instances, the first frequency band, the second frequency band, and the third frequency band each have the same bandwidth. For example, each of the first, second, and third frequency band may have a bandwidth of about <NUM>, <NUM>, or <NUM>.

In some instances, the first frequency band have a different bandwidth than at least one of the second frequency band or the third frequency band. For example, the first frequency band may have a bandwidth of about <NUM> and the second and third frequency band may each have a frequency of about <NUM>.

In some instances, the second frequency band and the third frequency band are contiguous in frequency. For example, the first frequency band may correspond to the frequency band <NUM>, the second frequency band may correspond to the frequency band <NUM>, and the first frequency band may correspond to the frequency band <NUM> as shown in <FIG>.

In some instances, the second frequency band and the third frequency band are spaced apart by a frequency separation. For example, the first frequency band may correspond to the frequency band <NUM>, the second frequency band may correspond to the frequency band <NUM>, and the first frequency band may correspond to the frequency band <NUM> as shown in <FIG>. Alternatively, the first frequency band may correspond to the frequency band <NUM>, the second frequency band may correspond to the frequency band <NUM>, and the first frequency band may correspond to the frequency band <NUM> as shown in <FIG>. In some instances, the frequency separation between the second frequency band and the third frequency band is based on the second pathloss.

In some instances, the block <NUM> includes modulating, by a LO at the UE, the third data at an offset from a DC frequency to produce a RF signal in the second frequency band and downconverting, by the LO at the UE, a RF signal carrying the fourth data in the third frequency band to the DC frequency. In some instances, the UE may utilize the configuration shown in <FIG> where a single LO <NUM> used for the offset transmit modulation and the zero IF receive conversion.

In some instances, the UE may receive an allocation for the SFFD operation when the UE is located at a central region (e.g., the central regions <NUM>, <NUM>, and/or <NUM>) of a cell (e.g., the cells <NUM>, <NUM>, and/or <NUM>) served by the BS. The UE may receive an allocation for the offset-frequency FD operation when the UE travels to a periphery of the cell (e.g., in the peripheral regions <NUM>, <NUM>, and/or <NUM>).

In some instances, the first, second, and third frequency bands may be mmWave bands.

<FIG> is a flow diagram of a communication method <NUM> according to some aspects of the present disclosure. Blocks 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 or other suitable means for performing the blocks. For example, a wireless communication device, such as the BSs <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>, may utilize one or more components, such as the processor <NUM>, the memory <NUM>, the FD communication module <NUM>, the transceiver <NUM>, the modem <NUM>, and the one or more antennas <NUM>, to execute the blocks of method <NUM>. The method <NUM> may employ similar SFFD and offset-frequency FD allocation mechanisms discussed above with respect to <FIG> and <FIG>. As illustrated, the method <NUM> includes a number of enumerated blocks, but aspects of the method <NUM> may include additional blocks before, after, and in between the enumerated blocks. In some aspects, one or more of the enumerated blocks may be omitted or performed in a different order.

At block <NUM>, responsive to a first pathloss between a BS and a first UE satisfying a threshold for an SFFD operation, the BS transmits first data to the UE over a first frequency band while receiving second data from the UE over the first frequency band. The first UE may be similar to the UEs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>. The BS may be similar to the BSs <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>. In some instances, the BS may utilize one or more components, such as the processor <NUM>, the FD communication module <NUM>, the transceiver <NUM>, the modem <NUM>, and the one or more antennas <NUM>, to transmit the first data to the UE over the first frequency band while receiving the second data from the UE over the first frequency band. The BS may transmit the first data to the UE using a group of resource blocks occupying the first frequency band in a carrier-bandwidth (e.g., the carrier-bandwidths <NUM>, <NUM>, and/or <NUM>) while receiving the second data from the UE in the same group of resource blocks occupying the first frequency band.

At block <NUM>, responsive to a second pathloss between the BS and a second UE failing to satisfy the threshold, the BS transmits third data to the second UE over a second frequency band while receiving fourth data from the second UE at the BS over a third frequency band that is distinct from the second frequency band according to an offset-frequency FD operation. The second UE may be similar to the UEs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>. In some instances, the BS may utilize one or more components, such as the processor <NUM>, the FD communication module <NUM>, the transceiver <NUM>, the modem <NUM>, and the one or more antennas <NUM>, to transmit the third data to the second UE over the second frequency band while receiving the fourth data from the second UE over the third frequency band. The BS may transmit the third data to the UE using a group of resource blocks occupying the second frequency band in the carrier-bandwidth while receiving the fourth data from the UE in a group of resource blocks occupying the third frequency band in the carrier-bandwidth.

In some instances, the second frequency band and the third frequency band are spaced apart by a frequency separation. For example, the first frequency band may correspond to the frequency band <NUM>, the second frequency band may correspond to the frequency band <NUM>, and the first frequency band may correspond to the frequency band <NUM> as shown in <FIG>. Alternatively, the first frequency band may correspond to the frequency band <NUM>, the second frequency band may correspond to the frequency band <NUM>, and the first frequency band may correspond to the frequency band <NUM> as shown in <FIG>. In some instances, the frequency separation between the second frequency band and the third frequency band is based on the second pathloss. In some instances, the method <NUM> includes determining, by the BS, the frequency separation between the second frequency band and the third frequency band based on the second pathloss. In some instances, the BS may utilize one or more components, such as the processor <NUM>, the FD communication module <NUM>, and/or the memory <NUM>, to determine the frequency separation for the allocation of the second and third frequency band based on the second pathloss. For instance, the BS may store a LUT in the memory, where the LUT may include a mapping between distance or pathloss to frequency separation. The BS may utilize the processor to perform the table lookup based on the second pathloss or a distance estimated from the second pathloss.

In some instances, the method <NUM> further includes responsive to a third pathloss between the BS and a third UE failing to satisfy the threshold, transmitting fifth data from the BS to the third UE over a fourth frequency band while receiving sixth data from the third UE at the BS over a fifth frequency band that is distinct from the fourth frequency band, where the second frequency band and the third frequency band are spaced apart by at least one of the fourth frequency band or the fifth frequency band. In some instances, the BS may utilize one or more components, such as the processor <NUM>, the FD communication module <NUM>, the transceiver <NUM>, the modem <NUM>, and the one or more antennas <NUM>, to transmit the fifth data to the third UE over the fourth frequency band while receiving the sixth data from the second UE over the fifth frequency band.

In some instances, the method <NUM> further includes transmitting, by the BS to the first UE, an allocation indicating the first frequency band for the SFFD operation based on a comparison between the first pathloss and the threshold. The method <NUM> further includes transmitting, by the BS to the second UE, an allocation indicating the second frequency band and the third frequency band for the offset-frequency FD operation. In some instances, the BS may utilize one or more components, such as the processor <NUM>, the FD communication module <NUM>, the transceiver <NUM>, the modem <NUM>, and the one or more antennas <NUM>, to transmit the allocation indicating the first frequency band for the SFFD operation to the first UE based on a comparison between the first pathloss and the threshold and the allocation indicating the second and third frequency bands for the offset-frequency FD operation to the second UE based on a comparison between the second pathloss and the threshold.

In some instances, the first UE and the second UE may correspond to the same UE. The BS may assign the SFFD operation when the UE is located at a central region (e.g., the central regions <NUM>, <NUM>, and/or <NUM>) of a cell (e.g., the cells <NUM>, <NUM>, and/or <NUM>) served by the BS. The BS assign the offset-frequency FD operation when the UE travels to a periphery of the cell (e.g., in the peripheral regions <NUM>, <NUM>, and/or <NUM>).

Claim 1:
A method for a user equipment, UE, comprising:
responsive to a first pathloss between the UE and a base station, BS, satisfying a threshold for a same-frequency full-duplex, SFFD, operation, transmitting first data from the UE to the BS over a first frequency band while receiving second data from the BS at the UE over the first frequency band (<NUM>); and
responsive to a second pathloss between the UE and the BS failing to satisfy the threshold, transmitting third data from the UE to the BS over a second frequency band while simultaneously receiving fourth data from the BS at the UE over a third frequency band that is distinct from the second frequency band according to an offset-frequency full-duplex, FD, operation (<NUM>), wherein the second frequency band and the third frequency band are within a same carrier bandwidth, and wherein the second frequency band and the third frequency band are spaced apart by a frequency separation; and
wherein the frequency separation between the second frequency band and the third frequency band is based on the second pathloss.