Joint user activity detection and channel information estimation in extra-large MIMO (XL-MIMO) systems with non-stationarities proceeds by: receiving signals and initialization of a channel estimation; performing soft interference cancel check, whereby, if the soft interference cancel check result is negative, the calculation of residual mean and variance is performed; whereby, if the soft interference cancel check result is positive, the extrinsic mean and variance is calculated directly; whereby, if the soft interference cancel check result is negative, the calculation of residual mean and variance is used, whereby the calculation of tentative estimation includes activity factors calculation; if reaching the maximum is not fulfilled, soft interference cancel check is performed; whereby, if reaching the maximum is fulfilled, the proceeding ends.

A method for performing self-interference cancellation by a communication device which uses an FDR mode can comprise the steps of: measuring the strength of a residual self-interference signal, after antenna and analog self-interference cancellation, for each subband with respect to a predetermined number of subbands configured in a communication device; determining the order of a nonlinear self-interference signal component, to be considered for channel estimation of a nonlinear self-interference signal, for each subband on the basis of the strength of the residual self-interference signal that has been measured for each subband; and performing channel estimation of the nonlinear self-interference signal on the basis of the order that has been determined for each subband.

A jones matrix is obtained using coefficients of an equalizer; a parameter of the jones matrix is obtained; a coefficient of an X axis polarization state or a Y axis polarization state in the coefficients is adjusted using the parameter of the jones matrix when the coefficients have singularity characteristics, or energy corresponding to each coefficient of X or Y axis polarization state under each order of a filter in the equalizer is determined using two coefficients of an X or Y axis polarization state in the equalizer coefficients; and a central position of a coefficient tap of X or Y axis polarization state of the equalizer is adjusted using the energy corresponding to each coefficient of X or Y axis polarization state under each order of the filter when the coefficient tap of the X axis or Y axis polarization state of the equalizer deviates from the central position.

In a noise canceler, interference signals received by sub-antennas 12 are cross-correlated by a first correlation-value calculation unit and the peaks of the interference signals are detected by a first peak detector. Interference signal information is acquired by a first-interference-signal information acquisition unit and the interference signals are synthesized by an interference signal synthesizer. A signal received by a main antenna and the synthesized interference signal are correlated by a second correlation-value calculation unit and the peak of the synthesized interference signal is detected by a second peak detector. The interference signal information is acquired by a second interference-signal-information acquisition unit and an interference signal replica is generated by an interference signal replica generator. The interference signal replica is subtracted by an interference signal removal unit from the signal received by the main antenna.

An apparatus and method for flexible adjustment of the uplink-downlink ratio configuration for each enhanced node B (eNodeB) within a wireless communications network is disclosed herein. In one embodiment, a given eNodeB is configured to determine a current or subsequent uplink-downlink ratio configuration for a pre-determined time period. The determined current or subsequent uplink-downlink ratio configuration is encoded into a special physical downlink control channel (PDCCH), the special PDCCH included in at least one radio frame according to the pre-determined time period. The radio frame including the special PDCCH is transmitted to user equipment served by the given eNodeB.

Aspects of the disclosure relate to inter-link interference cancellation for reducing or mitigating interference from signals in different directions (e.g., uplink and downlink directions). A wireless communication device (i.e., a victim device subject to inter-link interference) may determine a time offset or lead time of an interfering signal from an offending device. Based on the determined time offset, the victim device may perform interference cancellation or suppression to reduce or mitigate the interference of the interfering signal. Other aspects, embodiments, and features are also claimed and described.

Systems and methods for mitigating the effect of in-band interference. The methods comprise: receiving a signal comprising at least one interfering signal component; generating a soft value for each symbol in at least one interfering signal component; and using the soft values to cancel at least one interfering signal component from the signal to mitigate the effect of interference. The soft value represents a most likely value for the symbol which is obtained by: determining a probability metric between an actual value of the symbol and each of a plurality of possible symbol values using a scaling value representing an estimate of the noise level in the signal received by the device; generating current local probabilities for the plurality of possible symbol values using the probability metric; and using the current local probabilities to determine the soft value.

A frequency domain resource configuration method and apparatus, the method including obtaining, by a base station, a first frequency hopping parameter set of UE in N sub-bands, where the N sub-bands have a mapping relationship with a frequency hopping pattern that is indicated by the first frequency hopping parameter set, where the sub-band is a length of consecutive frequency domain resources in a system bandwidth, and where N1, and further including sending, by the base station, first configuration information to the UE, where the first configuration information includes sub-band identifiers of the N sub-bands and the first frequency hopping parameter set.

An operation method of an in-band full duplex (IFD) multiple-input multiple-output (MIMO) transceiver, including a reception part, a transmission part, an analog self-interference (SI) generator, and a self-interference cancellation (SIC) controller, may comprise generating, at the SIC controller, a control signal for analog SIC and digital SIC and outputting the control signal to the reception part and the analog SI generator; cancelling, at the SIC controller, SI of a transmission signal of the transmission part based on the control signal; and cancelling, at the reception part, SI of a signal of the reception part based on the control signal.

Circuits for producing signals representative of mean and variance estimations for quadrature amplitude modulation (QAM) are provided where the circuits comprise: sequentially repeated first circuit modules and sequentially repeated second circuit modules configured for producing updates in the corresponding estimation iterations. In one embodiment, a closest negative integer power of 2 is used as a substitute multiplicand when multiplying together two or more outputs of hyperbolic function generating units where the substituted for output is less than one. Size and complexity of the corresponding multiplier can then be reduced.