A communication apparatus comprises a generator that generates frequency resource position information corresponding to a first information which is based on the communication quality information received from user equipments, the frequency resource position information indicating validity or invalidity of the first information for each frequency resource, and a transmitter that transmits the first information, the frequency resource position information and a cell ID which the frequency resource position is applied, to another communication apparatus via a backhaul.

Systems and methods are disclosed for utilizing unused bit resources to convey restrictions on parameters evaluated for a feedback report in a Multiple-Input Multiple-Output (MIMO) wireless communication system. In one embodiment, a method of operation of a transmitting node in a wireless network includes transmitting a feedback restriction indicator to a receiving node, where the feedback restriction indicator is an unused bit resource in one or more instances of a control channel that is indicative of one or more desired restrictions on parameters to be evaluated by the receiving node for a feedback report to be provided from the receiving node. The method of operation of the transmitting node further includes receiving the feedback report from the receiving node, where the feedback report is limited according to the feedback restriction indicator.

A transmission scheme for transmitting a first modulated signal and a second modulated signal in the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a precoding weight by a baseband signal after a first mapping and a baseband signal after a second mapping and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.

Aspects described herein relate to wireless communications. According to some aspects, a first base station may coordinate with a second base station to select beamforming codewords. The first base station may receive an index indicating beamforming codewords used by a second base station. The first base station may select a beamforming codeword for use in transmitting signals to a wireless device based on the beamforming codeword indicated by the second base station.

Wireless communications systems and methods related to over-the-air uplink-downlink (UL-DL) reciprocity calibration. A central unit transmits downlink (DL) calibration reference signal (RS) and a calibration request. The central unit receives, in response to the calibration request, a first uplink (UL) calibration RS and a first DL channel estimate associated with a first transmission point (TP) and a first wireless communication device. The central unit transmits a DL coordinated multipoint (CoMP) joint transmission signal according to an uplink-downlink (UL-DL) reciprocity calibration. The UL-DL reciprocity calibration is based on at least a first UL channel estimate based on the first UL calibration RS, the first DL channel estimate, a second UL channel estimate associated with a second TP and the first wireless communication device, and a second DL channel estimate associated with the second TP and the first wireless communication device.

Various embodiments disclosed herein provide for a base station device that can determine which layers should be mapped to codewords in a multi-layer, multi-antenna transmission. The base station device can transmit reference signals to a user equipment device, with each reference signal associated with a respective codeword to layer mapping combination, and the user equipment can send channel state information associated with each reference signal back to the base station device, and the base station device can rank each combination in terms of spectral efficiency or capacity and/or throughput. The base station device can inform the user equipment of the ranked combinations by sending a bit map with the ranked combinations to the user equipment device.

Various embodiments disclosed herein provide for a base station device that can determine which layers should be mapped to codewords in a multi-layer, multi-antenna transmission. The base station device can transmit reference signals to a user equipment device, with each reference signal associated with a respective codeword to layer mapping combination, and the user equipment can send channel state information associated with each reference signal back to the base station device, and the base station device can rank each combination in terms of spectral efficiency or capacity and/or throughput. The base station device can inform the user equipment of the ranked combinations by sending a bit map with the ranked combinations to the user equipment device.

Aspects presented herein may enable a receiving device to receive high frequency signals with a simpler receiver to reduce the overall complexity and cost associated with the receiver. In one aspect, an apparatus receives a reference signal from a second wireless device. The apparatus measures amplitude and phase of the reference signal relative to a set point. The apparatus transmits channel flattening information in a precoding feedback to the second wireless device, the precoding feedback including at least a difference between the amplitude of the reference signal and the set point for a sub-band.

Methods, apparatus, and systems for wireless communications are described. Example methods, devices, and systems are described that utilize a precoding matrix indicator (PMI) computed based at least in part on first signals received via a first cell and on second signals received via a second cell. Information in a measurement information message may be used as part of computing a PMI. The measurement information message may indicate resources of a first cell and a second cell for use in computing the PMI. A wireless device may receive first signals via the first cell and second signals via the second cell based on information in the measurement information message, and may use these signals to compute the PMI. The computed PMI may be used in communications with a base station. For example, the wireless device may receive a packet beamformed employing the computed PMI.

A transmission scheme for transmitting a first modulated signal and a second modulated signal in the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a precoding weight by a baseband signal after a first mapping and a baseband signal after a second mapping and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.