FREQUENCY DEPENDENT RESIDUAL SIDE BAND TRAINING SIGNALS

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a frequency dependent residual side band (FDRSB) training signal via one or more time resources. The UE may transmit an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal. The UE may receive a communication, reception of the communication comprising applying a UE FDRSB correction that is based at least in part on the FDRSB training signal. Numerous other aspects are described.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for frequency dependent residual side band (FDRSB) training signals.

BACKGROUND

SUMMARY

Some aspects described herein relate to a method of wireless communication performed by a user equipment (UE). The method may include receiving a frequency dependent residual side band (FDRSB) training signal via one or more time resources. The method may include transmitting an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal. The method may include receiving a communication, reception of the communication comprising applying a UE FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to a method of wireless communication performed by a UE. The method may include receiving a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, reception of the FDRSB comprising receiving the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers. The method may include transmitting an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to a method of wireless communication performed by a network node. The method may include transmitting a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, transmission of the FDRSB comprising transmitting the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers. The method may include receiving an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to a UE for wireless communication. The user equipment may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to receive an FDRSB training signal via one or more time resources. The one or more processors may be configured to transmit an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal. The one or more processors may be configured to receive a communication, reception of the communication comprising applying a UE FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to a UE for wireless communication. The UE may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to receive a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, reception of the FDRSB comprising receiving the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers. The one or more processors may be configured to transmit an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to a network node for wireless communication. The network node may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to transmit a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, transmission of the FDRSB comprising transmitting the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers. The one or more processors may be configured to receive an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a UE. The set of instructions, when executed by one or more processors of the UE, may cause the UE to receive an FDRSB training signal via one or more time resources. The set of instructions, when executed by one or more processors of the UE, may cause the UE to transmit an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal. The set of instructions, when executed by one or more processors of the UE, may cause the UE to receive a communication, reception of the communication comprising applying a UE FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication. The set of instructions, when executed by one or more processors of a UE, may cause the UE to receive a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, reception of the FDRSB comprising receiving the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers. The set of instructions, when executed by one or more processors of the UE, may cause the UE to transmit an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a network node. The set of instructions, when executed by one or more processors of the network node, may cause the network node to transmit a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, transmission of the FDRSB comprising transmitting the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers. The set of instructions, when executed by one or more processors of the network node, may cause the network node to receive an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for receiving an FDRSB training signal via one or more time resources. The apparatus may include means for transmitting an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal. The apparatus may include means for receiving a communication, reception of the communication comprising applying an apparatus FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for receiving a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, reception of the FDRSB comprising receiving the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers. The apparatus may include means for transmitting an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for transmitting a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, transmission of the FDRSB comprising transmitting the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers. The apparatus may include means for receiving an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

DETAILED DESCRIPTION

In some aspects, the UE120may include a communication manager140. As described in more detail elsewhere herein, the communication manager140may receive a frequency dependent residual side band (FDRSB) training signal via one or more time resources; transmit an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal; and receive a communication, reception of the communication comprising applying a UE FDRSB correction that is based at least in part on the FDRSB training signal. Additionally, or alternatively, the communication manager140may perform one or more other operations described herein.

In some aspects, the communication manager140may receive a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, reception of the FDRSB comprising receiving the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers; and transmit an indication of FDRSB correction that is based at least in part on the FDRSB training signal. Additionally, or alternatively, the communication manager140may perform one or more other operations described herein.

In some aspects, the network node110may include a communication manager150. As described in more detail elsewhere herein, the communication manager150may transmit a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, transmission of the FDRSB comprising transmitting the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers; and receive an indication of FDRSB correction that is based at least in part on the FDRSB training signal. Additionally, or alternatively, the communication manager150may perform one or more other operations described herein.

In some aspects, a UE (e.g., the UE120) includes means for receiving an FDRSB training signal via one or more time resources; means for transmitting an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal; and/or means for receiving a communication, reception of the communication comprising applying a UE FDRSB correction that is based at least in part on the FDRSB training signal. The means for the UE to perform operations described herein may include, for example, one or more of communication manager140, antenna252, modem254, MIMO detector256, receive processor258, transmit processor264, TX MIMO processor266, controller/processor280, or memory282.

In some aspects, a UE (e.g., the UE120) includes means for receiving a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, reception of the FDRSB comprising receiving the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers; and/or means for transmitting an indication of FDRSB correction that is based at least in part on the FDRSB training signal. The means for the UE to perform operations described herein may include, for example, one or more of communication manager140, antenna252, modem254, MIMO detector256, receive processor258, transmit processor264, TX MIMO processor266, controller/processor280, or memory282.

In some aspects, a network node (e.g., the network node110) includes means for transmitting a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, transmission of the FDRSB comprising transmitting the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers; and/or means for receiving an indication of FDRSB correction that is based at least in part on the FDRSB training signal. The means for the network node to perform operations described herein may include, for example, one or more of communication manager150, transmit processor220, TX MIMO processor230, modem232, antenna234, MIMO detector236, receive processor238, controller/processor240, memory242, or scheduler246.

FIG.4is a diagram illustrating an example400of a communication having FDRSB, in accordance with the present disclosure. As shown inFIG.4, a transmitting device may transmit a communication to a receiving device. The transmitting device may use multiple antenna elements (also referred to as “antennas”) to transmit the communication using beamforming. The communication may include signals transmitted via multiple time-frequency resources (e.g., via multiple subcarriers and/or resource blocks on one or more symbols and/or slots).

As shown inFIG.4, the transmitting device may receive multiple streams402for transmission to the receiving device. The streams may include data and/or control signaling for transmission to the receiving device. A digital precoder404may receive the streams402and apply precoding to the streams402. After applying the precoding to the streams402, the digital precoder404may output digitally precoded streams406.

A set of IQ modulators408(e.g., IQ modulators408A through408N) may receive the digitally precoded streams406from the digital precoder404(e.g., directly or indirectly). The IQ modulators408may modulate the digitally precoded streams406to map bits of the digitally precoded streams406to constellation points associated with bit values of the digitally precoded streams406. For example, the IQ modulators408may apply modulation based at least in part on applying amplitudes, in a Q (quadrature) dimension and an I (in-phase) dimension in an IQ plane, according to an MCS of communications to the receiving device. However, the IQ modulators408may cause FDRSB (e.g., an IQ mismatch, an FDRSB impairment, and/or FDRSB error) to the digital precoded streams406based at least in part on, for example, imperfections of the IQ modulators408. This FDRSB may cause signaling on a first subcarrier to interfere with signaling on a second subcarrier that is a mirror of the first subcarrier about a carrier frequency. For example, the first subcarrier may be a distance from the carrier frequency in a positive direction (e.g., above the carrier frequency), and the second subcarrier may be the same distance from the carrier frequency in a negative direction (e.g., below the carrier frequency).

The IQ modulators408may provide modulated signals associated with the digitally precoded streams406to antenna elements410for transmission over the air to the receiving device. Based at least in part on digital precoding, the antenna elements410may transmit the modulated signals associated with the digitally precoded streams406via a transmission beam412. In some examples, the antenna elements410may transmit the modulated signals via one or more transmission beams412. As the modulated signals propagate over the air to the receiving device, channel conditions414may affect the modulated signals. For example, the channel conditions414may affect a signal-to-noise ratio (SNR) and/or a signal-to-interference-plus-noise ratio (SINR) of the modulated signals as received at the receiving device.

The receiving device may receive the modulated signals having effects from channel conditions414. Additionally, based at least in part on transmission using the IQ modulators408, the modulated signals may have FDRSB. The antenna elements416may provide received streams418(e.g., the modulated signals having effects of channel conditions414and FDRSB) to a demodulator420. In some examples, the demodulator420may be unable to correctly demodulate the received streams418based at least in part on the FDRSB associated with the IQ modulators408. In these examples, the receiving device and the transmitting device may consume power, processing, power, and/or communication resources to detect and correct demodulation errors or failures in the received streams418. For example, the receiving device may provide hybrid automatic repeat request (HARQ) acknowledgment (HARQ-ACK) feedback to indicate a demodulation and/or decoding error, which may trigger a retransmission of communications associated with the streams402.

In some examples, IQ mismatch (also referred to as FDRSB) is an inherent impairment of an IQ modulator. Cancellation of this impairment may improve link performance by, for example, improving support for MCSs with improved spectral efficiency and/or reducing error rates of communications.

A network node may use multiple antenna groups (e.g., groups of one or more antenna elements), with the multiple antenna groups each connected to a different IQ modulator. The network node may not support estimation of transmission FDRSB (e.g., FDRSB of a signal transmitted by the UE) based at least in part on cost and complexity. For example, to support estimation of transmission FDRSB, the network node may use dedicated hardware including an RF feedback chain for each IQ modulator. The UE may sample transmitted signals using the RF feedback chain, apply an analog-to-digital conversion, and then perform FDRSB estimation and correction.

In some aspects described herein, a network node may transmit a training signal to a UE from which the UE may estimate FDRSB correction for a composite of all used transmission antenna groups and provide feedback (e.g., over-the-air (OTA)) to the network node. The network node may use the feedback to correct the FDRSB with reduced cost and complexity, relative to internal estimation of the FDRSB within the network node.

Based at least in part on using OTA FDRSB feedback and correction, the network node may correct a composite FDRSB, which may not be supported by a network node performing internal estimation of the FDRSB based at least in part on the network node not having knowledge of a channel transfer function as observed by the UE. Additionally, or alternatively, the UE may need calibration for reception FDRSB, which may be costly and complex to perform using internal estimation.

In some aspects described herein, a UE may support joint estimation (e.g., using a same FDRSB training signal to identify FDRSB correction for the UE and for a network node). In some aspects, the UE may identify a first component of FDRSB associated with the network node and a second component of FDRSB associated with the UE. In some aspects, the FDRSB training signal may occupy a bandwidth that includes a bandwidth on which the network node transmits communications to the UE. Additionally, or alternatively, the FDRSB training signal may support capturing the bandwidth for the UE and the network node while also supporting separating the UE FDRSB and the network node FDRSB.

In some aspects, a network node FDRSB (e.g., transmission FDRSB) and a UE FDRSB (e.g., reception FDRSB) may be simultaneously identified (e.g., over the entire bandwidth) by allocating two or more training symbols (e.g., time resources used for FDRSB training signals). More symbols may be used to improve processing gain for training signals.

In some aspects, an estimation process may support the network node to be assisted with a UE or multiple UEs to identify FDRSB correction (e.g., an FDRSB correction filter). The estimation process may also support each UE to identify UE FDRSB correction for FDRSB at the UE.

In some aspects, the UE and/or the network node may decide at which periodicity to perform FDRSB estimation (e.g., based at least in part on aging of a previous FDRSB estimation, a change in temperature, and/or an update in beamforming parameters). Additionally, or alternatively, the network node and/or the UE may decide how wide to configure the FDRSB training signal. For example, a width (e.g., in a frequency domain) of the FDRSB training signal may depend on a bandwidth used for transmissions by the network node (e.g., for transmissions of data and/or other communications). This improves accuracy of FDRSB correction relative to an FDRSB signal that is narrower than the bandwidth used for transmission by the UE and reduces power consumption relative to an FDRSB signal that is wider than the bandwidth used for transmission by the UE.

Based at least in part on the UE estimating a composite of the FDRSB (e.g., a total of FDRSBs from all network node antenna groups and/or transmission chains used by the network node), an estimation and correction dimension may be reduced, relative to estimating the FDRSB per transmission chain and correcting per transmission chain.

In some aspects, the UE may use a phase shifter when receiving the FDRSB training signal. The phase shifter may have a non-flat magnitude and/or phase response over the bandwidth (e.g., the phase shifter may not be an ideal phase shifter).

Each IQ modulator of the network node may be impaired with FDRSB, which can be modeled as: Zi[k]=S[k]+Fi[k]·S*[−k], where S[k] is the FDRSB training signal in a frequency domain FD and Fi[k] is the network node FDRSB impairment of the i-th modulator.

The received signal on the UE side may include Zi[k] after passing the beam-former and the channel:

Substituting

On the UE side, the received Y[k] passes through the phase shifter: Y [k]⇒Y[k]·C[k]. The UE reception IQ demodulator may then impair the signal with its own

The FDRSB training signal may be configured to support solving for the network node FDRSB and for the UE FDRSB. For example, the training signal S[k] may include even subcarriers only for positive frequencies (e.g., frequencies above the carrier frequency) and odd subcarriers only for negative frequencies (e.g., below the carrier frequency). In this way, the FDRSB impairment, which is reflected on the mirror subcarriers, would always leak into a vacant tone, thus supporting measurement of: a measurement of the training signal:

and a measurement of the FDRSB that leaked from the training signal to mirror subcarriers:

In some aspects, the FDRSB training signal may include a second stage in which the training signal S[k] is flipped in the frequency domain and transmitted again. In this way, the UE may measure the FDRSB training signal (e.g., meas1) and the FDRSB (meas2) on subcarriers that were used for the other during a first stage. In some aspects, the second stage may be omitted and the UE may interpolate values of the FDRSB and the FDRSB training signal on missing subcarriers.

A measurement by the UE may include

To measure the FDRSB training signal, the UE may receive the FDRSB training signal on active main tones k0={ . . . −5 −3 −1 2 46 . . . }. The UE may configure a phase shifter C[k] to a first value of shifting to be approximately C(φ1)[k]≈ejφ1. The UE may measure a gain of a main tone (e.g., subcarriers on which the FDRSB training signal is transmitted): meas2(φ1)=Cmain[k0]C(φ1)[k0] for k0={ . . . −5 −3 −1 2 4 6 . . . }; and for a mirror tone: meas2(φ1)=C*main[k0]C(φ1)*[K0]FUE.FDRSB[−k0]+CgNb.FDRSB[−k0]C(φ1)[−k0] for k0={ . . . −5 −3 −1 2 4 6 . . . }.

The UE may apply the measurements to a first equation, where:

A second part of the FDRSB estimation may include a second part associated with a second phase shift. The UE may set the phase shifter C[k] to a second mode of roughly shifting by C(φ2)[k]≈ejφ2and may repeat processes for obtaining meas1(φ2), meas2(φ2), and meas3(φ2)using the second phase shift. The UE may use a second equation:

The UE may combine equations for the first and second phase shifts to obtain:

The UE may solve for

an (FUE.FDRSB[−k0]), which are the optimal FDRSB corrections for the network node and for the UE, respectively.

Bypassing the phase shifter on the UE side (e.g., after FDRSB estimation is over), the UE may observe: Y2[k]=S[k]Cmain[k]+S*[−k](C*main[−k]FUE.FDRSB[k]+CgNb.FDRSB[k]). Based at least in part on this, the network node FDRSB correction filter is

and the UE FDRSB correction

Substituting the network node FDRSB correction equation yields the following

Applying the UE FDRSB correction equation yields:

Based at least in part on canceling out the equation above, a cleaned Y2[k]=S[k]Cmain[k]+no FDRSB.

In some aspects, the first phase shifter value and the second phase shifter value may be 90 degrees out of phase. However other values of phase shifter would work as well. Some values may use repetition of the training process to compensate for noise enhancement with processing gain.

Additionally, the phase shifter is allowed to have a non-flat phase and/or magnitude response, since the set of equations above does not assume ideal phase shifters.

Based at least in part on the UE supporting identification of the network node FDRSB (also referred to as gNB FDRSB) and UE FDRSB from a same FDRSB training signal (e.g., using two or more time resources that may be consecutive), the UE may conserve computing power, network, and/or communication resources that may have otherwise been used to obtain the network node FDRSB and the UE FDRSB separately.

FIG.5is a diagram of an example500associated with FDRSB training signals, in accordance with the present disclosure. As shown inFIG.5, a network node (e.g., network node110, a CU, a DU, and/or an RU) may communicate with a UE (e.g., UE120). In some aspects, the network node and the UE may be part of a wireless network (e.g., wireless network100). The UE and the network node may have established a wireless connection prior to operations shown inFIG.5.

As shown by reference number505, the network node may transmit, and the UE may receive, configuration information. In some aspects, the UE may receive the configuration information via one or more of radio resource control (RRC) signaling, control information (DCI), among other examples. In some aspects, the configuration information may include an indication of one or more configuration parameters (e.g., already known to the UE and/or previously indicated by the network node or other network device) for selection by the UE, and/or explicit configuration information for the UE to use to configure the UE, among other examples.

In some aspects, the configuration information may indicate that the UE is to transmit a request for an allocation for receiving an FDRSB training signal. In some aspects, the configuration information may indicate that the UE is to request the allocation for transmitting the FDRSB training signal based at least in part on one or more conditions, such as a change in temperature, a change in channel conditions, a change in transmission beam, and/or a change in transmission power or other parameters, among other examples. In some aspects, the configuration information may indicate that the UE is to receive the FDRSB training signal with vacancies on mirror subcarriers (e.g., subcarriers used to transmit the FDRSB training signal may have vacant and/or empty mirror subcarriers). In some aspects, the configuration information may indicate a pattern and/or resolution for receiving the FDRSB training signal.

The UE may configure itself based at least in part on the configuration information. In some aspects, the UE may be configured to perform one or more operations described herein based at least in part on the configuration information.

As shown by reference number510, the UE may transmit, and the network node may receive, a capabilities report. In some aspects, the capabilities report may indicate UE support for joint identification of network node FDRSB and UE FDRSB using a same FDRSB training signal (e.g., a multi-symbol FDRSB training signal). In some aspects, the capabilities report may indicate support for one or more candidate patterns and/or candidate resolutions for transmitting the FDRSB training signal.

As shown by reference number515, the UE may transmit, and the network node may receive, a request for an allocation for receiving an FDRSB training signal. In some aspects, the UE may transmit the request based at least in part on a change of channel conditions, temperature conditions, and/or beamforming parameters, among other examples.

As shown by reference number520, the UE may receive, and the network node may transmit, a configuration for receiving the FDRSB training signal. In some aspects, the network node may transmit the configuration based at least in part on receiving the request described in connection with reference number515. In some aspects, the network node may transmit the configuration independently from (e.g., in the absence of) receiving the request described in connection with reference number515. For example, the network node may transmit the configuration (e.g., an allocation for receiving the FDRSB training signal) based at least in part on detecting a change in temperature, channel conditions, and/or beamforming parameters (e.g., precoding), among other examples. In some aspects, the network node may transmit the configuration based at least in part on a request from the UE, a periodicity of the FDRSB training signal, and/or an amount of time from a most recent FDRSB training signal.

In some aspects, the configuration may indicate selection of a pattern for transmitting the FDRSB training signal. For example, the configuration may indicate selection of a first pattern of the first set of subcarriers and/or a second pattern of the second set of subcarriers from a set of candidate subcarrier patterns for FDRSB training signals. In some aspects, the selection of the first pattern and/or or the second pattern is based at least in part on a selection by the UE or a selection by a network node associated with the FDRSB correction.

As shown by reference number525, the UE may receive, and the network node may transmit, the FDRSB training signal on a first set of subcarriers and a second set of subcarriers, with a mirror of the first set of subcarriers being non-overlapping with the second set of subcarriers. Additionally, or alternatively, a mirror of the second set of subcarriers about the carrier frequency may be non-overlapping with the first set of subcarriers. For example, the network node may transmit the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, with a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers.

In some aspects, the mirror of the first set of subcarriers may be interleaved with the second set of subcarriers. In some aspects, a combination of the first set of subcarriers and the second set of subcarriers spans a first range of subcarriers that includes a second range of subcarriers on which the UE is configured to communicate with the network node associated with the FDRSB correction. For example, the network node may transmit the FDRSB training signal on the first set of subcarriers that is at least as wide as the second range of subcarriers and includes the second set of subcarriers such that the FDRSB training signal spans at least the frequency domain of network node transmissions.

In some aspects, the UE may receive a first portion of the FDRSB training signal via a first time resource, where the first portion includes the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency. A mirror of the first set of subcarriers about the carrier frequency may be non-overlapping with the second set of subcarriers. The UE may also receive a second portion of the FDRSB training signal via a second time resource, where the second portion includes the FDRSB training signal on a third set of subcarriers that are lower than the carrier frequency and on a fourth set of subcarriers that are higher than the carrier frequency, with a mirror of the third set of subcarriers about the carrier frequency being non-overlapping with the fourth set of subcarriers. In some aspects, the mirror of the first set of subcarriers includes the third set of subcarriers, a mirror of the second set of subcarriers includes the fourth set of subcarriers, the mirror of the third set of subcarriers includes the first set of subcarriers, and/or a mirror of the fourth set of subcarriers includes the second set of subcarriers.

In some aspects, the UE may interpolate network node FDRSB correction information associated with the first set of subcarriers and/or the second set of subcarriers. In some aspects, the UE may interpolate UE FDRSB correction information associated with the first set of subcarriers and/or the second set of subcarriers.

In some aspects, the UE may use a pattern identified in the configuration for receiving the FDRSB training signal, in the configuration information, and/or in a communication protocol, among other examples. The pattern may have an even resolution (e.g., with a consistent spacing between subcarriers of the first set of subcarriers and/or between subcarriers of the second set of subcarriers) or have irregular spacing. The pattern may be configured with signal vacancy on subcarriers that are mirrors from subcarriers carrying the FDRSB training signal (e.g., the first set of subcarriers and the second set of subcarriers). For example, the network node may not transmit a signal on, or may allocate no transmission power to, the subcarriers that are mirrors from the subcarriers carrying the FDRSB training signal.

In some aspects, the UE may receive the FDRSB training signal based at least in part on a periodicity for transmitting the FDRSB training signal, a request for FDRSB correction from a network node associated with the FDRSB correction, an update to one or more of a precoder or a beam used for a transmission to the network node, or an update to a temperature at the UE, among other examples. In some aspects, the periodicity may be based at least in part on a requested periodicity indicated by the UE, a configuration from the network node, or a communication protocol, among other examples.

In some aspects, the UE may receive the FDRSB training signal using a number of time resources that is based at least in part on a signal strength associated with communications between the UE and the network node associated with the FDRSB correction. For example, the network node may use more than two time resources for the FDRSB training signal based at least in part on a signal strength (e.g., SNR) failing to satisfy a threshold. Using multiple time resources may support processing gains that may improve coverage of the FDRSB training signal and/or improve accuracy of the FDRSB correction.

In some aspects, the UE may receive one or more additional iterations of the FDRSB training signal. In these aspects, identification of the network node FDRSB correction information may be based at least in part on the one or more additional iterations of the FDRSB training signal. In some aspects, the UE may receive the one or more additional iterations of the FDRSB training signal based at least in part on an associated channel having an SNR that fails to satisfy a threshold (e.g., to improve processing gains).

As shown by reference number530, the UE may apply phase shifts when receiving the FDRSB training signals. In some aspects, the UE may receive a first portion of the FDRSB training signal via a first time resource and using a first phase shift, and may receive a second portion of the FDRSB training signal via a second time resource and using a second phase shift that is different from the first phase shift. For example, the first phase shift and the second phase shift may be out of phase by approximately 90 degrees.

As shown by reference number535, the UE may identify FDRSB correction for the network node (e.g., network node FDRSB correction) based at least in part on the FDRSB training signal.

As shown by reference number540, the UE may identify FDRSB for the UE (e.g., UE FDRSB correction) based at least in part on the FDRSB training signal. In some aspects, the UE FDRSB correction is based at least in part on a difference in measurements of the FDRSB training signal during the first time resource and measurements of the FDRSB training signal during the second time resource.

As shown by reference number545, the UE may transmit, and the network node may receive, an indication of the FDRSB correction for the network node. In some aspects, the indication of the FDRSB correction may indicate a filter or other processing parameters to apply to signals before transmitting, with the filter or other processing parameters configured to reduce FDRSB by the network node. In some aspects, the UE may transmit the indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal.

As shown by reference number550, the network node may apply FDRSB correction. For example, the network node may apply a filter and/or other modification to a signal before transmitting the signal OTA. In some aspects, the network node may multiply a signal by a matrix that applies the FDRSB correction.

As shown by reference number555, the UE may receive, and the network node may transmit, a communication having the network node FDRSB correction applied.

As shown by reference number560, the UE may apply FDRSB correction. For example, the UE may apply a filter and/or other modification to a signal after receiving the signal. In some aspects, the UE may multiply a signal by a matrix that applies the FDRSB correction for the UE.

Based at least in part on the UE supporting identification of the network node FDRSB (a.so referred to as gNB FDRSB) and UE FDRSB from a same FDRSB training signal (e.g., using two or more time resources that may be consecutive), the UE may conserve computing power, network, and/or communication resources that may have otherwise been used to obtain the network node FDRSB and the UE FDRSB separately.

FIG.6is a diagram illustrating an example600of a communication having FDRSB, in accordance with the present disclosure. As shown inFIG.6, a transmitting device may transmit a communication to a receiving device. The transmitting device may use multiple antenna elements (also referred to as “antennas”) to transmit the communication using beamforming. The communication may include signals transmitted via multiple time-frequency resources (e.g., via multiple subcarriers and/or resource blocks on one or more symbols and/or slots). The communication may include an FDRSB training signal and/or one or more streams of data, among other examples.

As shown inFIG.6, the transmitting device may receive multiple streams602for transmission to the receiving device. The streams may include an FDRSB training signal, data, and/or control signaling for transmission to the receiving device. The transmitting device may use an FDRSB corrector604to generate FDRSB corrected streams606from the streams602. In some aspects, the transmitting device may use the FDRSB corrector604based at least in part on the multiple streams602including data and/or control signaling and/or based at least in part on the multiple streams602not including an FDRSB training signal (e.g., an uncorrected FDRSB training signal may be used to identify FDRSB correction information). For example, the transmitting device may apply an FDRSB correction that is based at least in part on feedback from the receiving device, as described herein.

The transmitting device may use a digital precoder608to apply precoding to the FDRSB corrected streams606to generate precoded streams610. The digital precoder608may provide (e.g., directly or indirectly) the precoded streams610to a set of IQ modulators612(e.g., IQ modulators612A through612N). The IQ modulators612may modulate the precoded streams610to map bits of the precoded streams610to constellation points associated with bit values of the precoded streams610. For example, the IQ modulators612may apply modulation based at least in part on applying amplitudes, in a Q dimension and an I dimension in an IQ plane, according to an MCS of communications to the receiving device.

The IQ modulators612may cause FDRSB (e.g., an IQ mismatch, an FDRSB impairment, and/or FDRSB error) to the precoded streams610based at least in part on, for example, imperfections of the IQ modulators612. This FDRSB may cause signaling on a first subcarrier to interfere with a second subcarrier that is a mirror of the first subcarrier about a carrier frequency. For example, the first subcarrier may be a distance from the carrier frequency in a positive direction (e.g., above the carrier frequency), and the second subcarrier may be the same distance from the carrier frequency in a negative direction (e.g., below the carrier frequency). In another example, a subcarrier at location +n may interfere with a subcarrier at location −n, where location 0 (zero) is the carrier frequency.

The IQ modulators612may provide modulated streams614to antenna elements616for transmission over the air to the receiving device. Based at least in part on precoding, the antenna elements616may transmit the modulated streams via one or more transmission beams618. As the modulated signals of the modulated streams propagate over the air to the receiving device, channel conditions620may affect the modulated streams. For example, the channel conditions620may affect an SNR and/or an SINR of the modulated signals as received at the receiving device.

The receiving device may use one or more antenna elements622to receive the modulated streams614having effects from channel conditions620. Additionally, based at least in part on transmission using the IQ modulators612, the modulated streams614may have FDRSB. Received streams624(e.g., the modulated signals having effects of channel conditions620and FDRSB) may be shifted based at least in part on combining the received streams624with an output of a phase shifter626(e.g., based at least in part on the received streams including an FDRSB training signal). The phase shifter626may apply a first phase shift to a first portion of a communication carried on the received streams624(e.g., to FDRSB training signal on a first time resource, such as a symbol) and/or may apply a second phase shift to a second portion of the communication carried on the received streams624. In this way, the first portion may have a different phase shift applied than a second portion. The receiving device may apply the phase shifter to only received streams624that include an FDRSB training signal and/or may not apply the phase shifter626to received streams624that include data.

The receiving device may provide shifted streams628to an IQ demodulator (IQ demod)630. The IQ demodulator630may demodulate the shifted streams628. IQ demodulator630may introduce receiver FDRSB to the shifted streams628based at least in part on imperfections of the IQ demodulator630. The IQ demodulator630may provide demodulated streams632, having receiver FDRSB applied (e.g., from the IQ demodulator630) and transmitter FDRSB applied (e.g., from the IQ modulators612), to an FDRSB estimator and/or corrector634. The FDRSB estimator and/or corrector634may estimate and/or identify transmitter FDRSB and receiver FDRSB based at least in part on the demodulated streams632having both FDRSBs applied and based at least in part on the phase shifter626applying different phase shifts to the received streams in different time resources. The receiving device may provide FDRSB correction information636, including transmitter FDRSB correction information, to the transmitting device. Additionally, or alternatively, the receiving device may identify and/or store receiver FDRSB correction information for application by the FDRSB estimator and/or corrector634or by the IQ demodulator630to subsequent communications from the transmitting device.

In this way, the receiving device may use the FDRSB training signal, received via one or more time resources, to obtain FDRSB correction information for the transmitting device and the receiving device.

FIG.7is a diagram illustrating an example700of an FDRSB pattern, in accordance with the present disclosure. In some aspects, a transmitting device, such as a network node, may apply the FDRSB pattern for transmission of FDRSB training signals. As shown by reference number700, the transmitting device may transmit FDRSB training signals on a first set of subcarriers702and a second set of subcarriers704.

A mirror706of the second set of subcarriers704is shown at locations that are mirrored about a center frequency from subcarriers of the second set of subcarriers704. The mirror706of the second set of subcarriers704may be interleaved with the first set of subcarriers702. For example, a subcarrier of the mirror706of the second set of subcarriers704may be at a frequency location that is between subcarriers that are occupied by subcarriers of the first set of subcarriers702(e.g., between consecutive occupied subcarriers of the first set of subcarriers702).

Similarly, mirror708of the first set of subcarriers702is shown at locations that are mirrored about a center frequency from subcarriers of the first set of subcarriers702. The mirror706of the first set of subcarriers702may be interleaved with the first set of subcarriers702. For example, a subcarrier of the mirror708of the first set of subcarriers702may be at a frequency location that is between subcarriers that are occupied by subcarriers of the second set of subcarriers704(e.g., between consecutive occupied subcarriers of the second set of subcarriers704).

In some aspects, the UE may measure FDRSB on subcarriers of the mirror706of the second set of subcarriers704and on subcarriers of the mirror708of the second set of subcarriers702. Based at least in part on measuring the FDRSB on vacant subcarriers (e.g., vacant from a transmission perspective, but including FDRSB), the UE may measure the FDRSB separately from the FDRSB training signal as transmitted by the network node.

In some aspects, the UE may receive the FDRSB training signal on an additional time resource (e.g., a second time resources, such as a symbol, that is adjacent to a first time resource that included the FDRSB transmitted on the first set of subcarriers702and the second set of subcarriers704). In some aspects, the FDRSB training signal on the additional time resource may include the FDRSB training signal transmitted on a third set of subcarriers and a fourth set of subcarriers that are different from the first set of subcarriers and the second set of subcarriers. For example, the third set of subcarriers may include the mirror706of the second set of subcarriers704and the fourth set of subcarriers may include the mirror708of the first set of subcarriers702.

Based at least in part on the UE receiving the FDRSB training signal on the first time resource and on the second time resource, the UE may measure FDRSB on additional subcarriers. Alternatively, where the UE receives the FDRSB training signal on only the first time resource, the UE may extrapolate FDRSB for subcarriers that are not within the mirror706of the second set of subcarriers704or the mirror708of the first set of subcarriers702(e.g., for subcarriers of the first set of subcarriers702and the subcarriers of the second set of subcarriers704).

In some aspects, the UE may receive the FDRSB training signal, having a pattern as shown in example700or in another pattern, during a first time and/or second time resource, and apply a first phase shift. The UE may additionally receive the FDRSB training signal on a third and/or fourth time resource and apply a second phase shift. The UE may use the different phase shifts to separate UE FDRSB from network node FDRSB. The UE may apply FDRSB correction based at least in part on the UE FDRSB and may provide the network node FDRSB and/or correction information to the network node for the network node to apply network node FDRSB correction to transmissions.

As indicated above,FIG.7is provided as an example. Other examples may differ from what is described with regard toFIG.7. For example, other patterns may be used for the first set of subcarriers702and the second set of subcarriers704. The other patterns may have different densities (e.g., with a different number of vacant subcarriers between consecutive and/or adjacent occupied subcarriers), variable densities (e.g., where numbers of vacant subcarriers between consecutive and/or adjacent occupied subcarriers are not required to be the same), different lengths (e.g., numbers of consecutive subcarriers that are occupied in a pattern such as {1,1,0,0,1,1,0,0 . . . }, with 1 indicating occupied subcarriers and 0 indicating vacant subcarriers), among other examples.

In some networks (e.g., sub-THz networks), a network node may use multiple antennas (e.g., multi-panel, multi-TRP, multi-RRH network nodes) connected to multiple IQ modulators to improve beam forming. In some of these networks, the network node may be burdened with estimation of the FDRSB for each associated IQ modulator, such as IQ modulators at the multiple antennas, which may not be co-located (e.g., for configurations with multiple TRPs or multiple RRHs, among other examples). This incurs high cost and complexity for the network node to perform an FDRSB mitigation procedure, as the network node may require hardware (e.g., dedicated hardware) for that purpose, with the hardware including an RF feedback chain for each of the multiple modulators, a sampler (e.g., an ADC), and/or an FDRSB estimator.

In some aspects, the UE may use a multi-port FDRSB training signal (e.g., associated with multi-panel, multi-TRP, and/or multi-RRH communications) along with a PHY procedure such that the network node may assist the UE in canceling associated transmission FDRSB (e.g., downlink FDRSB) over multi-port, multi-panel, multi-TRP, and/or multi-RRH communications. The FDRSB training signal may reduce a complexity of an FDRSB correction procedure in which the UE estimates the composite network node FDRSB. For example, the FDRSB training signal may support capturing both the multi-port FDRSB as well as wide-band properties, thus enabling OTA feedback of the correction filters to the network node. The network node may inform the UE of a slot or other time resource at which the FDRSB training signal is to be transmitted (e.g., with an indication of one or more symbols on which the FDRSB training signal is to be transmitted). The UE may measure the FDRSB training signal and provide feedback as FDRSB correction information based at least in part on a calculated FDRSB correction filter.

In some aspects, the network node may transmit a special training signal that allows for low complexity and fast estimation of a composite FDRSB over multiple (e.g., all) transmit ports of the network node in multi-TRP mode, multi-RRH mode, and/or a multi-panel mode). The UE may perform FDRSB estimation for multi-port or multi-TRP modes using a single FDRSB training signal as a result of a structure of the FDRSB training signal.

In this way, the network node may send a training signal to the UE from which the UE may estimate FDRSB correction information for a composite of all IQ modulators associated with network node transmission antennas (e.g., all active transmission antennas), which may reduce consumption of network node resources (e.g., computing and/or power resources) and may reduce hardware costs associated with FDRSB suppression for multiple network node transmission antennas, in comparison to estimating per transmission chain and correcting per transmission chain in different resources.

Using the transmission signal, the network node may collect FDRSB correction responses from various UEs and combine them (e.g., average them), which may improve accuracy of FDRSB correction information and/or may improve FDRSB suppression. The network node cannot estimate a composite FDRSB using local detection and/or measurements because the network node has no knowledge of a channel transfer function as observed by the UE (e.g., the composite FDRSB depends on the channel).

In some aspects, the network node may use fast training for FDRSB correction. Fast training may include capturing FDRSB responses (e.g., associated with FDRSB correction information) associated with the multiple transmission antennas and the multiple ports, rather than having the network node estimate each of them separately (e.g., per port and per IQ modulator). Based at least in part on the FDRSB varying over time and/or temperature, the network node may update FDRSB correction often, making fast training conserve network resources and/or improve accuracy associated with updating FDRSB correction. In some aspects, the network node may decide a periodicity to use for FDRSB estimation. The periodicity may be based at least in part on environmental factors that affect a rate at which the FDRSB may vary, overhead consumed by the FDRSB training signal, and/or throughput that is based at least in part on overhead and error rates, among other examples.

Based at least in part on the UE providing the FDRSB correction information (e.g., FDRSB feedback and/or over-the-air-estimated composite FDRSB correction information) to the network node, the network node may transmit communications with reduced FDRSB. In this way, the UE may receive the communications with reduced error rates and/or with increased spectral efficiency.

Each of the IQ modulators are impaired with FDRSB impairment, which can be modeled as Zn(p)[k]=Sn[k]+Fn(p)[k]·S*nÅ[−k]. {Sn[k]}n=1Nis the multi-port precoded training signal in the frequency domain (e.g., assume that initially, an FDRSB correction unit is bypassed in this stage). {Fn(p)[k]} is the FDRSB impairment of the ith IQ modulator in the pth RRH. F×S is the FDRSB.

The received signal Yr[k] on the rth reception UE antenna includes Zn(p)[k] after passing the analog beam-former and the channel as:

As shown in the model above, the rth reception UE antenna receives a desired component interfered with an undesired composite FDRSB term:

The equations may be combined to form:

Thus, the rthreceive antenna sees a desired component (e.g., a linear combination of the layers) interfered with undesired FDRSB component:

An unbiased MMSE equalizer applied to the received signal {Yr[k]}r=1nrxwill suppress the inter layer leakage in the desired term, but will be unable to treat the FDRSB term.

Denoting the equalizer as Eir[k], the (i,r)thelement of the unbiased MMSE equalizer matrix (L is FDRSB leakage) has an output of:

where εj[k] denotes a negligible level of residual un-equalized inter-layer leakage and Lij[k] represents the FDRSB leakage level of the jthlayer into ithlayer when observing at the equalizer output: {circumflex over (x)}i[k]≈xi[k]+Σj=1 . . . nlayersx*j[−k]Lij[k].

An estimation unit of the UE may estimate the FDRSB leakage coefficients Lij[k]jthlayer=>ithlayer at frequency bin k may be:

where the coefficients Lij[k] may be feedbacked from the UE to the network node for applying FDRSB correction in a layers domain in the following form:

Then the equalizer output would be free of FDRSB:

and then:

which provides an FDRSB-free signal (e.g., or with negligible FDRSB):

The FDRSB-free signal on the reception side contains a negligible inter-layer leakage term (but no FDRSB leakage):

In the above expression, a residual inter-layer leakage is negligible because it is on the order of L2. This means that if the IQ impairment L is around −30 dB, then this residual term is at the order of −60 dB. Furthermore, if needed, this term can be suppressed further on the UE side by using the equalizer output:

In this way, the residual inter-layer leakage term would be reduced even further and would become even more negligible (at the order of L4, where, for the example of 30 dB, the residual inter-layer leakage term would be 30 dB*4=120 dB). This can continue further (e.g., iteratively on different equalizers), until reaching a satisfactory level of negligible residual level of inter-layer leakage.

The training signal {xi[k]}i=port 1port nlayersmay be configured in such a way that it enables simultaneous multi-port estimation of the inter-layer FDRSB leakage coefficients: jth layer=>ith layer at frequency bin k: Lij[k].

When observing at the equalizer output over the output vector of dimension Mayers: {circumflex over (x)}i[k]≈xi[k]+Σj=1 . . . nlayersx*j[−k]Lij[k]. The UE may estimate the leakage coefficients based at least in part on the multi-port training signal being designed so that a positive subcarrier always corresponds to a vacant mirror negative subcarrier (e.g., subcarriers on which the FDRSB training signal is transmitted have vacant mirrored subcarriers). In this way, a vacant subcarrier may become populated by a single component of FDRSB leakage, rather than a sum of leakages. This may support a simplified estimation of the FDRSB coefficient Lij[k].

In some aspects, the different ports may be FDM-spread along a frequency bandwidth. For example, subcarriers of different ports may be interleaved through the frequency bandwidth, such as shown inFIG.7.

In some aspects, a multi-port training signal X[k] may take different shapes and/or patterns, as long as each subcarrier has a vacant mirror subcarrier.

The estimation of Lij[k] may provide a frequency resolution for FDRSB measurements of 2*nlayer(e.g., k=8 resolution in the example of nlayer=4). The UE may use interpolation along the frequency domain to calculate missing values of coefficients for FDRSB measurements (e.g., the UE may retrieve a coefficient value for every k). In some aspects, this interpolation can be performed by the network node to reduce the UE-to-network-node feedback traffic (e.g., overhead). An interpolation may provide satisfactory accuracy, since the FDRSB likely has slight variation across adjacent subcarriers.

FIG.8is a diagram of an example800associated with FDRSB training signals, in accordance with the present disclosure. As shown inFIG.8, a network node (e.g., network node110, a CU, a DU, and/or an RU) may communicate with a UE (e.g., UE120). In some aspects, the network node and the UE may be part of a wireless network (e.g., wireless network100). The UE and the network node may have established a wireless connection prior to operations shown inFIG.8.

As shown by reference number805, the network node may transmit, and the UE may receive, configuration information. In some aspects, the UE may receive the configuration information via one or more of radio resource control (RRC) signaling, control information (DCI), among other examples. In some aspects, the configuration information may include an indication of one or more configuration parameters (e.g., already known to the UE and/or previously indicated by the network node or other network device) for selection by the UE, and/or explicit configuration information for the UE to use to configure the UE, among other examples.

In some aspects, the configuration information may indicate that the UE is to transmit a capabilities report that indicates a capability to transmit FDRSB correction information using measurements of an FDRSB training signal transmitted via multiple ports. In some aspects, the configuration information may indicate a pattern for different ports associated with the FDRSB training signal. For example, the configuration information may indicate densities of subcarriers that carrier the FDRSB training signal (e.g.,1/2density so each subcarrier includes the FDRSB training signal or a mirror of an FDRSB training signal), lengths (e.g., numbers of consecutive subcarriers that are occupied in a pattern such as {1,1,0,0,1,1,0,0 . . . }, with 1 indicating occupied subcarriers and 0 indicating vacant subcarriers), among other examples.

The UE may configure itself based at least in part on the configuration information. In some aspects, the UE may be configured to perform one or more operations described herein based at least in part on the configuration information.

As shown by reference number810, the UE may transmit, and the network node may receive, a capabilities report. In some aspects, the capabilities report may indicate UE support identifying FDRSB correction information using measurements of an FDRSB training signal transmitted via multiple ports.

As shown by reference number815, the UE may transmit, and the network node may receive, a request for an allocation for receiving an FDRSB training signal.

As shown by reference number820, the UE may receive, and the network node may transmit, a configuration for receiving the FDRSB training signal transmitted via multiple ports. The configuration may indicate a configuration of a first set of subcarriers and a second set of subcarriers that are to carry the FDRSB training signal. The first set of subcarriers may be below a center frequency (e.g., a carrier frequency) and the second set of subcarriers may be above the center frequency, with vacant subcarriers at locations that mirror the first set of subcarriers (e.g., above the center frequency and/or interleaved with the second set of subcarriers) and the second set of subcarriers (e.g., below the center frequency and/or interleaved with the first set of subcarriers).

The first set of subcarriers may include a first subset of subcarriers allocated to a first port of an associated network node and a second subset of subcarriers allocated to a second port of the associated network node. Similarly, the second set of subcarriers may include a third subset of subcarriers allocated to the first port and a fourth subset of subcarriers allocated to the second port of the associated network node. Additionally, or alternatively, first set of subcarriers and/or the second set of subcarriers may include additional subsets of subcarriers allocated to additional ports (e.g., a third subset of subcarriers allocated to a third port of the associated network node).

In some aspects, the third subset of subcarriers may be vacant based at least in part on the associated network node being configured to communicate with the UE via the first port and the second port, and being configured not to communicate with the UE via the third port. In this way, the first port and the second port may have a static allocation of subcarriers, regardless of whether the third subset is used for a third port.

For example, the configuration may indicate a periodicity of the FDRSB training signals and/or a pattern of ports used to transmit the FDRSB training signal. In some aspects, the configuration may indicate a static resolution of ports (e.g., a first port is allocated every eighth subcarrier regardless of a number of other ports used to transmit the FDRSB training signal) or a dynamic resolution of ports. For example, the FDRSB training signal may occupy every other subcarrier and occupied subcarriers may rotate through the ports used to transmit the FDRSB training signal (e.g., if only 2 ports are used, the first port and the second port may each have a resolution of every fourth subcarrier).

In some aspects, the configuration may indicate an allocation for the FDRSB training signal. For example, the configuration may indicate one or more time resources for receiving the FDRSB training signal. The one or more time resources may be referred to as FDRSB training symbols. In some aspects, the UE may receive the indication of the allocation and/or the configuration based at least in part on a change in temperature at the UE, a change in temperature at an associated network node, a precoding change for transmissions by the associated network node, a precoding change for transmissions by the UE, and/or an age of an update of the FDRSB correction, among other examples.

As shown by reference number825, the UE may receive, and the network node may transmit, the FDRSB training signal on a first set of subcarriers and a second set of subcarriers, with a mirror of the first set of subcarriers being non-overlapping with the second set of subcarriers. In some aspects, the multi-port FDRSB training signal may include transmissions of the FDRSB signal transmitted via different ports on interleaved subcarriers. In some aspects, the first set of subcarriers may be lower than a carrier frequency and the second set of subcarriers may be higher than the carrier frequency.

In some aspects, the UE may receive the FDRSB training signal on one or more time resources (e.g., one or more slots and/or one or more symbols within a slot). In some aspects, a number of time resources used for the FDRSB training signal may be based at least in part on channel conditions (e.g., SNR, RSRP, taps, Doppler shift, among other examples). In some aspects, the UE may receive the FDRSB training signal based at least in part on a configured pattern of allocations of subcarriers to different ports and/or to vacancy (e.g., with vacant subcarriers mirroring non-vacant subcarriers about the center frequency and/or carrier frequency).

In some aspects, the indication of the FDRSB correction may include separate information elements for different ports. For example, the indication of FDRSB correction may include a first information element associated with the first port and a second information element associated with the second port. In this way, the network node may send different FDRSB correction information to different devices (RRHs, TRPs, and/or panels) based at least in part on association of the different devices to different ports.

As shown by reference number830, the UE may identify FDRSB correction for multiple ports. The FDRSB correction may be based at least in part on the FDRSB training signal. In some aspects, the UE may receive one or more additional iterations of the FDRSB training signal, and the FDRSB correction may be based at least in part on the FDRSB training signal and the one or more additional iterations of the FDRSB training signal. In some aspects, the UE may receive, and the network node may transmit, the one or more additional iterations of the FDRSB training signal based at least in part on an associated channel having an SNR that fails to satisfy a threshold.

In some aspects, the UE may measure FDRSB on vacant subcarriers and associate the measured FDRSB on a particular vacant subcarrier with a mirrored subcarrier. In some aspects, the UE may interpolate network node FDRSB correction information (e.g., for subcarriers on which the UE did not measure FDRSB for a particular port) associated with the first set of subcarriers and/or associated with the second set of subcarriers. For example, if the UE measured FDRSB for the first port on subcarriers { . . . −34, −26, −18, −10, −2, 1, 9, 17, 25, 33 . . . }, the UE may interpolate FDRSB on subcarriers between the measured subcarriers. In some aspects, the UE may provide the measurements of the FDRSB and the network node may interpolate the FDRSB on the subcarriers between the measured subcarriers.

As shown by reference number835, the UE may transmit, and the network node may receive, an indication of the FDRSB correction (e.g., correction information) for the multiple ports. The indication of the FDRSB correction may be based at least in part on the FDRSB training signal and/or one or more iterations of the FDRSB training signal. In some aspects, the indication of the FDRSB correction includes information elements associated with individual subcarriers of the first set of subcarriers and/or information elements associated with individual subcarriers of the second set of subcarriers. In some aspects, the indication of the FDRSB correction comprises elements of a matrix that indicates the FDRSB at associated subcarriers.

As shown by reference number840, the network node may apply FDRSB correction.

As shown by reference number845, the UE may receive, and the network node may transmit, a communication having FDRSB correction applied. In some aspects, the communication may have a reduced FDRSB, which may reduce an error rate of the communication. In some aspects, the communication may have an increased MCS or other parameter associated with increased spectral efficiency based at least in part on the communication having FDRSB correction applied.

FIG.9is a diagram illustrating an example900of a communication having FDRSB, in accordance with the present disclosure. As shown inFIG.9, a transmitting device (e.g., a network node) may transmit a communication to a receiving device (e.g., a UE). The transmitting device may use multiple antenna element groups to transmit the communication using beamforming. The multiple antenna groups may be associated with different TRPs and/or RRHs. The communication may include signals transmitted via multiple time-frequency resources (e.g., via multiple subcarriers and/or resource blocks on one or more symbols and/or slots). The communication may include an FDRSB training signal and/or one or more streams of data, among other examples.

As shown inFIG.9, the receiving device may transmit FDRSB correction information902to the transmitting device. In some aspects, the receiving device may obtain the FDRSB correction information902based at least in part on receiving an FDRSB training signal, such as described in connection withFIGS.7-8. The FDRSB correction information902may include a set of information elements that are associated with different antenna groups used by the transmitting device to transmit to the receiving device.

As shown inFIG.9, the transmitting device may receive the FDRSB correction information902and provide the FDRSB correction information902to an FDRSB corrector904. The transmitting device may transmit the FDRSB correction information902via one or more intermediary devices, such as RRHs, TRPs, and/or RUs, among other examples. The FDRSB corrector904may apply FDRSB correction to streams for transmission to the receiving device. For example, the FDRSB corrector904may apply individual (e.g., allowed to be different) FDRSB correction for each port and/or for each IQ modulator used to transmit to the receiving device.

The FDRSB corrector904may provide FDRSB corrected streams906to a digital precoder908. After applying a digital precoding to support beam forming, the digital precoder908may provide precoded streams910to IQ modulators912(e.g., IQ modulators912A through912N). The IQ modulators912may modulate the precoded streams910to map bits of the precoded streams910to constellation points associated with bit values of the precoded streams910. For example, the IQ modulators912may apply modulation based at least in part on applying amplitudes, in a Q dimension and an I dimension in an IQ plane, according to an MCS of communications to the receiving device. The IQ modulators912may be located on different transmitters associated with the transmitting device. For example, the different transmitters may be RRHs and/or TRPs that are at different locations. The different transmitters may use different beams and/or different channels to communicate with the receiving device.

The IQ modulators912may cause FDRSB (e.g., an IQ mismatch, an FDRSB impairment, and/or FDRSB error) to the precoded streams910based at least in part on, for example, imperfections of the IQ modulators912. However, the FDRSB may be preemptively corrected using the FDRSB corrector904.

The IQ modulators912may provide modulated streams914to antenna groups916for transmission over the air to the receiving device. Based at least in part on precoding, the antenna groups916may transmit the modulated streams via transmission beams918. As the modulated signals of the modulated streams propagate over the air to the receiving device, channel conditions920may affect the modulated streams. For example, the channel conditions920may affect an SNR and/or an SINR of the modulated signals as received at the receiving device.

The receiving device may use one or more antenna elements922to receive the modulated streams914having effects from channel conditions920. Received streams924(e.g., the modulated signals having effects of channel conditions920) may be provided to an IQ demodulator (IQ demod)926. The IQ demodulator926may demodulate the received streams924and may provide the demodulated streams for decoding and reception of data from the streams.

In some aspects, the streams may include FDRSB training signals to update the FDRSB correction information902. In this case, the receiving device may provide the received streams (e.g., a portion of the received streams that include the FDRSB training signal) to an FDRSB estimator928. The FDRSB estimator928may use the FDRSB training signal (e.g., configured as described herein) to identify an update to the FDRSB correction information902.

FIG.10is a diagram illustrating an example1000of an FDRSB training signal, in accordance with the present disclosure. As shown inFIG.10, a transmitting device (e.g., a network node) may transmit an FDRSB training signal to a receiving device (e.g., a UE). The transmitting device may use multiple antenna element groups to transmit the FDRSB training signal using beamforming. The multiple antenna groups may be associated with different TRPs and/or RRHs. The FDRSB training signal may include signals transmitted via multiple time-frequency resources (e.g., via multiple subcarriers and/or resource blocks on one or more symbols and/or slots).

As shown by reference number1002, the FDRSB training signal may include a first set of subcarriers1002that are below a center frequency (e.g., a carrier frequency) and a second set of subcarriers1004that are above the center frequency. The first set of subcarriers1002and the second set of subcarriers1004may include subcarriers that do not overlap with a subcarrier that carries the FDRSB training signal (e.g., subcarriers that mirror the first set of subcarriers do not overlap with the second set of subcarriers, and subcarriers that mirror the second set of subcarriers do not overlap with the first set of subcarriers).

The first set of subcarriers1002and the second set of subcarriers1004also include subcarriers allocated to a set of ports (e.g., shown as ports1,2, and3). Each port may have subcarriers allocated in both of the first set of subcarriers1002and the second set of subcarriers1004. In some aspects, the subcarriers may be allocated to interleave subcarriers of different ports. For example, a pattern of allocated subcarriers (e.g., skipping vacant subcarriers) may be 1, 2, 3, 1, 2, 3, 1, 2, 3 . . . such that sequential occupied subcarriers cycle through the different ports.

As shown by reference number1006, occupied subcarriers may cause FDRSB on mirrored subcarriers. For example, an FDRSB training signal1008may cause FDRSB1010on subcarriers that mirror subcarriers that are allocated for the FDRSB training signal1008. As shown inFIG.10, an FDRSB training signal1008at subcarrier −1 causes FDRSB at subcarrier 1, an FDRSB training signal1008at subcarrier 2 causes FDRSB at subcarrier −2, an FDRSB training signal1008at subcarrier −3 causes FDRSB at subcarrier 3, an FDRSB training signal1008at subcarrier 4 causes FDRSB at subcarrier −4, etc.

Based at least in part on the mirror subcarriers being vacant (e.g., not allocated for transmission of the FDRSB training signal1008), the UE may measure the FDRSB isolated from the FDRSB training signal1008. Additionally, or alternatively, the UE may separately measure the FDRSB for different ports based at least in part on the ports being allocated on non-overlapping subcarriers.

As indicated above,FIG.10is provided as an example. Other examples may differ from what is described with respect toFIG.10.

FIG.11is a diagram illustrating an example process1100performed, for example, by a UE, in accordance with the present disclosure. Example process1100is an example where the UE (e.g., UE120) performs operations associated with FDRSB training signals.

As shown inFIG.11, in some aspects, process1100may include receiving an FDRSB training signal via one or more time resources (block1110). For example, the UE (e.g., using reception component1402and/or communication manager1408, depicted inFIG.14) may receive an FDRSB training signal via one or more time resources, as described above.

As further shown inFIG.11, in some aspects, process1100may include transmitting an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal (block1120). For example, the UE (e.g., using transmission component1404and/or communication manager1408, depicted inFIG.14) may transmit an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal, as described above.

As further shown inFIG.11, in some aspects, process1100may include receiving a communication, reception of the communication comprising applying a UE FDRSB correction that is based at least in part on the FDRSB training signal (block1130). For example, the UE (e.g., using reception component1402and/or communication manager1408, depicted inFIG.14) may receive a communication, reception of the communication comprising applying a UE FDRSB correction that is based at least in part on the FDRSB training signal, as described above.

In a first aspect, receiving the FDRSB training signal via one or more time resources comprises receiving a first portion of the FDRSB training signal via a first time resource and using a first phase shift, and receiving a second portion of the FDRSB training signal via a second time resource and using a second phase shift that is different from the first phase shift.

In a second aspect, alone or in combination with the first aspect, the first phase shift and the second phase shift are out of phase by approximately 90 degrees.

In a third aspect, alone or in combination with one or more of the first and second aspects, the UE FDRSB correction is based at least in part on a difference in measurements of the FDRSB training signal during the first time resource and measurements of the FDRSB training signal during the second time resource.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, receiving the FDRSB training signal via one or more time resources comprises receiving a first portion of the FDRSB training signal via a first time resource, the first portion including the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, wherein a mirror of the first set of subcarriers about the carrier frequency is non-overlapping with the second set of subcarriers.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, receiving the FDRSB training signal via one or more time resources comprises receiving a second portion of the FDRSB training signal via a second time resource, the second portion including the FDRSB training signal on a third set of subcarriers that are lower than the carrier frequency and on a fourth set of subcarriers that are higher than the carrier frequency, wherein a mirror of the third set of subcarriers about the carrier frequency is non-overlapping with the fourth set of subcarriers.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the mirror of the first set of subcarriers comprises the third set of subcarriers, a mirror of the second set of subcarriers comprises the fourth set of subcarriers, the mirror of the third set of subcarriers comprises the first set of subcarriers, or a mirror of the fourth set of subcarriers comprises the second set of subcarriers.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, process1100includes one or more of interpolating network node FDRSB correction information associated with the first set of subcarriers, interpolating network node FDRSB correction information associated with the second set of subcarriers, interpolating UE FDRSB correction information associated with the first set of subcarriers, or interpolating UE FDRSB correction information associated with the second set of subcarriers.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, process1100includes receiving an indication of an allocation of the one or more time resources for reception of the FDRSB training signal.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, reception of the indication of the allocation is based at least in part on one or more of a request from the UE, a change in temperature, a change in precoding used for communications between the UE and a network node, a periodicity of the FDRSB training signal, or an amount of time from a most recent FDRSB training signal.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the FDRSB training signal spans a bandwidth that is based at least in part on an operating bandwidth of a network node.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the communication has network node FDRSB correction applied based at least in part on the indication of the network node FDRSB correction information.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, process1100includes receiving an additional iteration of the FDRSB training signal, wherein the indication of the network node FDRSB correction information is based at least in part on the additional iteration of the FDRSB training signal.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, reception of the additional iteration of the FDRSB training signal is based at least in part on an associated channel having an SNR that fails to satisfy a threshold.

FIG.12is a diagram illustrating an example process1200performed, for example, by a UE, in accordance with the present disclosure. Example process1200is an example where the UE (e.g., UE120) performs operations associated with FDRSB training signals.

As shown inFIG.12, in some aspects, process1200may include receiving a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, reception of the FDRSB comprising receiving the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers (block1210). For example, the UE (e.g., using reception component1402and/or communication manager1408, depicted inFIG.14) may receive a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, reception of the FDRSB comprising receiving the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers, as described above.

As further shown inFIG.12, in some aspects, process1200may include transmitting an indication of FDRSB correction that is based at least in part on the FDRSB training signal (block1220). For example, the UE (e.g., using transmission component1404and/or communication manager1408, depicted inFIG.14) may transmit an indication of FDRSB correction that is based at least in part on the FDRSB training signal, as described above.

In a first aspect, process1200includes receiving an additional iteration of the FDRSB training signal, wherein the indication of the FDRSB correction is based at least in part on the additional iteration of the FDRSB training signal.

In a second aspect, alone or in combination with the first aspect, reception of the additional iteration of the FDRSB training signal is based at least in part on an associated channel having an SNR that fails to satisfy a threshold.

In a third aspect, alone or in combination with one or more of the first and second aspects, process1200includes receiving an indication of a configuration of the first set of subcarriers and the second set of subcarriers.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the first set of subcarriers comprises a first subset of subcarriers allocated to a first port of an associated network node, and the first set of subcarriers comprises a second subset of subcarriers allocated to a second port of the associated network node.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the first set of subcarriers comprises a third subset of subcarriers allocated to a third port of the associated network node.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the third subset of subcarriers are vacant based at least in part on the associated network node being configured to communicate with the UE via the first port and the second port, and being configured not to communicate with the UE via the third port.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the indication of FDRSB correction includes a first information element associated with the first port and a second information element associated with the second port.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, process1200includes one or more of interpolating FDRSB correction information associated with the first set of subcarriers, or interpolating network node FDRSB correction information associated with the second set of subcarriers.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the indication of the FDRSB correction comprises information elements associated with individual subcarriers of the first set of subcarriers, or information elements associated with individual subcarriers of the second set of subcarriers.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, process1200includes receiving an indication of an allocation for the FDRSB training signal.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, reception of the indication of the allocation for the FDRSB training signal is based at least in part on one or more of a change in temperature at the UE, a change in temperature at an associated network node, a precoding change for transmissions by the associated network node, a precoding change for transmissions by the UE, or an age of an update of the FDRSB correction.

FIG.13is a diagram illustrating an example process1300performed, for example, by a network node, in accordance with the present disclosure. Example process1300is an example where the network node (e.g., network node110) performs operations associated with FDRSB training signals.

As shown inFIG.13, in some aspects, process1300may include transmitting a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, transmission of the FDRSB comprising transmitting the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers (block1310). For example, the network node (e.g., using transmission component1504and/or communication manager1508, depicted inFIG.15) may transmit a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, transmission of the FDRSB comprising transmitting the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers, as described above.

As further shown inFIG.13, in some aspects, process1300may include receiving an indication of FDRSB correction that is based at least in part on the FDRSB training signal (block1320). For example, the network node (e.g., using reception component1502and/or communication manager1508, depicted inFIG.15) may receive an indication of FDRSB correction that is based at least in part on the FDRSB training signal, as described above.

In a first aspect, process1300includes transmitting an additional iteration of the FDRSB training signal, wherein the indication of the FDRSB correction is based at least in part on the additional iteration of the FDRSB training signal.

In a second aspect, alone or in combination with the first aspect, transmission of the additional iteration of the FDRSB training signal is based at least in part on an associated channel having an SNR that fails to satisfy a threshold.

In a third aspect, alone or in combination with one or more of the first and second aspects, process1300includes transmitting an indication of a configuration of the first set of subcarriers and the second set of subcarriers.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the first set of subcarriers comprises a first subset of subcarriers allocated to a first port of the network node, and the first set of subcarriers comprises a second subset of subcarriers allocated to a second port of the network node.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the first set of subcarriers comprises a third subset of subcarriers allocated to a third port of the network node.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the third subset of subcarriers are vacant based at least in part on the network node being configured to communicate with a UE via the first port and the second port, and being configured not to communicate with the UE via the third port.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the indication of FDRSB correction includes a first information element associated with the first port and a second information element associated with the second port.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the indication of the FDRSB correction comprises information elements associated with individual subcarriers of the first set of subcarriers, or information elements associated with individual subcarriers of the second set of subcarriers.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, process1300includes transmitting an indication of an allocation for the FDRSB training signal.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, transmission of the indication of the allocation for the FDRSB training signal is based at least in part on one or more of a change in temperature at a UE, a change in temperature at an network node, a precoding change for transmissions by the network node, a precoding change for transmissions by the UE, or an age of an update of the FDRSB correction.

FIG.14is a diagram of an example apparatus1400for wireless communication, in accordance with the present disclosure. The apparatus1400may be a UE, or a UE may include the apparatus1400. In some aspects, the apparatus1400includes a reception component1402, a transmission component1404, and/or a communication manager1408, which may be in communication with one another (for example, via one or more buses and/or one or more other components). In some aspects, the communication manager1408is the communication manager140described in connection withFIG.1. As shown, the apparatus1400may communicate with another apparatus1406, such as a UE or a network node (such as a CU, a DU, an RU, or a base station), using the reception component1402and the transmission component1404.

The communication manager1408may support operations of the reception component1402and/or the transmission component1404. For example, the communication manager1408may receive information associated with configuring reception of communications by the reception component1402and/or transmission of communications by the transmission component1404. Additionally, or alternatively, the communication manager1408may generate and/or provide control information to the reception component1402and/or the transmission component1404to control reception and/or transmission of communications.

The reception component1402may receive an FDRSB training signal via one or more time resources. The transmission component1404may transmit an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal. The reception component1402may receive a communication, reception of the communication comprising applying a UE FDRSB correction that is based at least in part on the FDRSB training signal.

The reception component1402may receive an indication of an allocation of the one or more time resources for reception of the FDRSB training signal.

The reception component1402may receive an additional iteration of the FDRSB training signal, wherein the indication of the network node FDRSB correction information is based at least in part on the additional iteration of the FDRSB training signal.

The reception component1402may receive a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, reception of the FDRSB comprising receiving the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers. The transmission component1404may transmit an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

The reception component1402may receive an additional iteration of the FDRSB training signal, wherein the indication of the FDRSB correction is based at least in part on the additional iteration of the FDRSB training signal.

The reception component1402may receive an indication of a configuration of the first set of subcarriers and the second set of subcarriers.

The reception component1402may receive an indication of an allocation for the FDRSB training signal.

FIG.15is a diagram of an example apparatus1500for wireless communication, in accordance with the present disclosure. The apparatus1500may be a network node, or a network node may include the apparatus1500. In some aspects, the apparatus1500includes a reception component1502, a transmission component1504, and/or a communication manager1508, which may be in communication with one another (for example, via one or more buses and/or one or more other components). In some aspects, the communication manager1508is the communication manager150described in connection withFIG.1. As shown, the apparatus1500may communicate with another apparatus1506, such as a UE or a network node (such as a CU, a DU, an RU, or a base station), using the reception component1502and the transmission component1504.

The reception component1502may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus1506. The reception component1502may provide received communications to one or more other components of the apparatus1500. In some aspects, the reception component1502may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components of the apparatus1500. In some aspects, the reception component1502may include one or more antennas, a modem, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the network node described in connection withFIG.2. In some aspects, the reception component1502and/or the transmission component1504may include or may be included in a network interface. The network interface may be configured to obtain and/or output signals for the apparatus1500via one or more communications links, such as a backhaul link, a midhaul link, and/or a fronthaul link.

The transmission component1504may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus1506. In some aspects, one or more other components of the apparatus1500may generate communications and may provide the generated communications to the transmission component1504for transmission to the apparatus1506. In some aspects, the transmission component1504may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus1506. In some aspects, the transmission component1504may include one or more antennas, a modem, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the network node described in connection withFIG.2. In some aspects, the transmission component1504may be co-located with the reception component1502in a transceiver.

The communication manager1508may support operations of the reception component1502and/or the transmission component1504. For example, the communication manager1508may receive information associated with configuring reception of communications by the reception component1502and/or transmission of communications by the transmission component1504. Additionally, or alternatively, the communication manager1508may generate and/or provide control information to the reception component1502and/or the transmission component1504to control reception and/or transmission of communications.

The transmission component1504may transmit a multi-port FDRSB training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, transmission of the FDRSB comprising transmitting the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers. The reception component1502may receive an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

The transmission component1504may transmit an additional iteration of the FDRSB training signal, wherein the indication of the FDRSB correction is based at least in part on the additional iteration of the FDRSB training signal.

The transmission component1504may transmit an indication of a configuration of the first set of subcarriers and the second set of subcarriers.

The transmission component1504may transmit an indication of an allocation for the FDRSB training signal.

The number and arrangement of components shown inFIG.15are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown inFIG.15. Furthermore, two or more components shown inFIG.15may be implemented within a single component, or a single component shown inFIG.15may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown inFIG.15may perform one or more functions described as being performed by another set of components shown inFIG.15.

Aspect 1: A method of wireless communication performed by a user equipment (UE), comprising: receiving a frequency dependent residual side band (FDRSB) training signal via one or more time resources; transmitting an indication of network node FDRSB correction information that is based at least in part on the FDRSB training signal; and receiving a communication, reception of the communication comprising applying a UE FDRSB correction that is based at least in part on the FDRSB training signal.

Aspect 2: The method of Aspect 1, wherein receiving the FDRSB training signal via one or more time resources comprises: receiving a first portion of the FDRSB training signal via a first time resource and using a first phase shift; and receiving a second portion of the FDRSB training signal via a second time resource and using a second phase shift that is different from the first phase shift.

Aspect 3: The method of Aspect 2, wherein the first phase shift and the second phase shift are out of phase by approximately 90 degrees.

Aspect 4: The method of Aspect 2, wherein the UE FDRSB correction is based at least in part on a difference in measurements of the FDRSB training signal during the first time resource and measurements of the FDRSB training signal during the second time resource.

Aspect 5: The method of any of Aspects 1-4, wherein receiving the FDRSB training signal via one or more time resources comprises: receiving a first portion of the FDRSB training signal via a first time resource, the first portion including the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, wherein a mirror of the first set of subcarriers about the carrier frequency is non-overlapping with the second set of subcarriers.

Aspect 6: The method of Aspect 5, wherein receiving the FDRSB training signal via one or more time resources comprises: receiving a second portion of the FDRSB training signal via a second time resource, the second portion including the FDRSB training signal on a third set of subcarriers that are lower than the carrier frequency and on a fourth set of subcarriers that are higher than the carrier frequency, wherein a mirror of the third set of subcarriers about the carrier frequency is non-overlapping with the fourth set of subcarriers.

Aspect 7: The method of Aspect 6, wherein the mirror of the first set of subcarriers comprises the third set of subcarriers, wherein a mirror of the second set of subcarriers comprises the fourth set of subcarriers, wherein the mirror of the third set of subcarriers comprises the first set of subcarriers, or wherein a mirror of the fourth set of subcarriers comprises the second set of subcarriers.

Aspect 8: The method of Aspect 5, further comprising one or more of: interpolating network node FDRSB correction information associated with the first set of subcarriers; interpolating network node FDRSB correction information associated with the second set of subcarriers; interpolating UE FDRSB correction information associated with the first set of subcarriers; or interpolating UE FDRSB correction information associated with the second set of subcarriers.

Aspect 9: The method of any of Aspects 1-8, further comprising: receiving an indication of an allocation of the one or more time resources for reception of the FDRSB training signal.

Aspect 10: The method of Aspect 9, wherein reception of the indication of the allocation is based at least in part on one or more of: a request from the UE, a change in temperature, a change in precoding used for communications between the UE and a network node, a periodicity of the FDRSB training signal, or an amount of time from a most recent FDRSB training signal.

Aspect 11: The method of any of Aspects 1-10, wherein the FDRSB training signal spans a bandwidth that is based at least in part on an operating bandwidth of a network node.

Aspect 12: The method of any of Aspects 1-11, wherein the communication has network node FDRSB correction applied based at least in part on the indication of the network node FDRSB correction information.

Aspect 13: The method of any of Aspects 1-12, further comprising receiving an additional iteration of the FDRSB training signal, wherein the indication of the network node FDRSB correction information is based at least in part on the additional iteration of the FDRSB training signal.

Aspect 14: The method of Aspect 13, wherein reception of the additional iteration of the FDRSB training signal is based at least in part on an associated channel having a signal-to-noise ratio (SNR) that fails to satisfy a threshold.

Aspect 15: A method of wireless communication performed by a user equipment (UE), comprising: receiving a multi-port frequency dependent residual side band (FDRSB) training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, reception of the FDRSB comprising receiving the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers; and transmitting an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

Aspect 16: The method of Aspect 15, further comprising receiving an additional iteration of the FDRSB training signal, wherein the indication of the FDRSB correction is based at least in part on the additional iteration of the FDRSB training signal.

Aspect 17: The method of Aspect 16, wherein reception of the additional iteration of the FDRSB training signal is based at least in part on an associated channel having a signal-to-noise ratio (SNR) that fails to satisfy a threshold.

Aspect 18: The method of any of Aspects 15-17, further comprising: receiving an indication of a configuration of the first set of subcarriers and the second set of subcarriers.

Aspect 19: The method of any of Aspects 15-18, wherein the first set of subcarriers comprises a first subset of subcarriers allocated to a first port of an associated network node, and wherein the first set of subcarriers comprises a second subset of subcarriers allocated to a second port of the associated network node.

Aspect 20: The method of Aspect 19, wherein the first set of subcarriers comprises a third subset of subcarriers allocated to a third port of the associated network node.

Aspect 21: The method of Aspect 20, wherein the third subset of subcarriers are vacant based at least in part on the associated network node being configured to communicate with the UE via the first port and the second port, and being configured not to communicate with the UE via the third port.

Aspect 22: The method of Aspect 19, wherein the indication of FDRSB correction includes a first information element associated with the first port and a second information element associated with the second port.

Aspect 23: The method of any of Aspects 15-22, further comprising one or more of: interpolating FDRSB correction information associated with the first set of subcarriers; or interpolating network node FDRSB correction information associated with the second set of subcarriers.

Aspect 24: The method of any of Aspects 15-23, wherein the indication of the FDRSB correction comprises: information elements associated with individual subcarriers of the first set of subcarriers, or information elements associated with individual subcarriers of the second set of subcarriers.

Aspect 25: The method of any of Aspects 15-24, further comprising: receiving an indication of an allocation for the FDRSB training signal.

Aspect 26: The method of Aspect 25, wherein reception of the indication of the allocation for the FDRSB training signal is based at least in part on one or more of: a change in temperature at the UE, a change in temperature at an associated network node, a precoding change for transmissions by the associated network node, a precoding change for transmissions by the UE, or an age of an update of the FDRSB correction.

Aspect 27: A method of wireless communication performed by a network node, comprising: transmitting a multi-port frequency dependent residual side band (FDRSB) training signal with the FDRSB signal transmitted via different ports on interleaved subcarriers, transmission of the FDRSB comprising transmitting the FDRSB training signal on a first set of subcarriers that are lower than a carrier frequency and on a second set of subcarriers that are higher than the carrier frequency, a mirror of the first set of subcarriers about the carrier frequency being non-overlapping with the second set of subcarriers; and receiving an indication of FDRSB correction that is based at least in part on the FDRSB training signal.

Aspect 28: The method of Aspect 27, further comprising transmitting an additional iteration of the FDRSB training signal, wherein the indication of the FDRSB correction is based at least in part on the additional iteration of the FDRSB training signal.

Aspect 29: The method of Aspect 28, wherein transmission of the additional iteration of the FDRSB training signal is based at least in part on an associated channel having a signal-to-noise ratio (SNR) that fails to satisfy a threshold.

Aspect 30: The method of any of Aspects 27-29, further comprising: transmitting an indication of a configuration of the first set of subcarriers and the second set of subcarriers.

Aspect 31: The method of any of Aspects 27-30, wherein the first set of subcarriers comprises a first subset of subcarriers allocated to a first port of the network node, and wherein the first set of subcarriers comprises a second subset of subcarriers allocated to a second port of the network node.

Aspect 32: The method of Aspect 31, wherein the first set of subcarriers comprises a third subset of subcarriers allocated to a third port of the network node.

Aspect 33: The method of Aspect 32, wherein the third subset of subcarriers are vacant based at least in part on the network node being configured to communicate with a user equipment (UE) via the first port and the second port, and being configured not to communicate with the UE via the third port.

Aspect 34: The method of Aspect 31, wherein the indication of FDRSB correction includes a first information element associated with the first port and a second information element associated with the second port.

Aspect 35: The method of any of Aspects 27-34, wherein the indication of the FDRSB correction comprises: information elements associated with individual subcarriers of the first set of subcarriers, or information elements associated with individual subcarriers of the second set of subcarriers.

Aspect 36: The method of any of Aspects 27-35, further comprising: transmitting an indication of an allocation for the FDRSB training signal.

Aspect 37: The method of Aspect 36, wherein transmission of the indication of the allocation for the FDRSB training signal is based at least in part on one or more of: a change in temperature at a user equipment (UE), a change in temperature at an network node, a precoding change for transmissions by the network node, a precoding change for transmissions by the UE, or an age of an update of the FDRSB correction.