Methods and apparatus for acquiring channel state information with channel reciprocity

A base station comprising a processor in communication with memory, the processor being configured to execute instructions stored in the memory that cause the processor to:

• configure a channel estimation process between a mobile device and the base station such that the mobile device estimates a set of channel characteristics for a downlink direction of the wireless communication channel corresponding to a first set of antennas, wherein the mobile device is configured to use the first set of antennas to transmit signals and a second set of antennas to receive signals, wherein the first set of antennas is part of the second set of antennas;
• estimate a set of channel characteristics for an uplink direction of the wireless communication channel based on signals transmitted by the mobile device over the first set of antennas;
• and
• receive a report associated with the set of channel characteristics for the downlink direction of the wireless communication channel from the mobile device, wherein the mobile device generates the report based on the estimated set of channel characteristics for the downlink direction of the wireless communication channel corresponding to the first set of antennas.

A mobile device, comprising:

• a plurality of antennas, wherein a first set of the plurality of antennas are used to transmit signals and a second set of the plurality of antennas are used to receive signals, wherein the first set of the plurality of antennas is part of the second set of the plurality of antennas;
• and
• a processor in communication with memory, the processor being configured to execute instructions stored in the memory that cause the processor to:
• transmit signals to a base station over the first set of the plurality of antennas;
• estimate a set of channel characteristics for a downlink direction of the wireless communication channel from the base station;
• and
• generate a report associated with a set of channel characteristics for a downlink direction of the wireless communication channel based on the estimated set of channel characteristics for the downlink direction of the wireless communication channel corresponding to the first set of the plurality of antennas.

A computerized method executed by a base station, comprising:

• configuring a channel estimation process between a mobile device and the base station such that the mobile device estimates a set of channel characteristics for a downlink direction of the wireless communication channel corresponding to a first set of antennas, wherein the mobile device is configured to use the first set of antennas to transmit signals and a second set of antennas to receive signals, wherein the first set of antennas is part of the second set of antennas;
• estimating a set of channel characteristics for an uplink direction of the wireless communication channel based on signals transmitted by the mobile device over the first set of antennas;
• and
• receiving a report associated with the set of channel characteristics for the downlink direction of the wireless communication channel from the mobile device, wherein the mobile device generates the report based on the estimated set of channel characteristics for the downlink direction of the wireless communication channel corresponding to the first set of antennas.

A computerized method for a mobile device, comprising:

• transmitting signals to a base station over a first set of a plurality of antennas, wherein the first set of the plurality of antennas are used to transmit signals and a second set of the plurality of antennas are used to receive signals, wherein the first set of the plurality of antennas is part of the second set of the plurality of antennas;
• estimating a set of channel characteristics for an downlink direction of the wireless communication channel, based on the signals received over the second set of the plurality of antennas;
• and
• generating a report associated with a set of channel characteristics for a downlink direction of the wireless communication channel based on the estimated set of channel characteristics for the downlink direction of the wireless communication channel corresponding to the first set of the plurality of antennas.

A mobile device configured to perform channel estimation of a wireless communication channel between the mobile device and the base station, the mobile device comprising:

• a transceiver comprising a set of antennas;
• and
• a processor in communication with memory and the transceiver, the processor being configured to execute instructions stored in the memory that cause the processor to:
• receive a signal indicative of a constraining beamforming implemented by the base station for the wireless communication channel, the signal indicative of the base station being restricted to use a set of precoders for a set of frequency sets, wherein the base station is restricted to use each precoder in the set of precoders for one associated frequency set from the set of frequency sets to perform beamforming.