Communication systems, devices, and methods for multicarrier frequency division duplexing
Examples described herein include examples of wireless communication devices, systems, and methods which may employ multicarrier frequency division duplexing (multicarrier-FDD) techniques. Such techniques may enhance capacity and/or latency of example beamforming and MIMO systems. In some examples, the techniques described herein may be particularly advantageous in fast changing channels. Example channel duplexing techniques and methods described herein may achieve more efficient handling of fast fading channels by space-time adaptive (STAP) and/or adaptive array systems.
1. A method comprising:
transmitting transmit signals to a first communication device, using a second communication device, in one or more first subcarrier frequencies; and
receiving receive signals at the second communication device, from the first communication device, in one or more second subcarrier frequencies; and
wherein the one or more first subcarrier frequencies are each different than each of the one or more second subcarrier frequencies, wherein the one or more first subcarriers is a neighboring subcarrier to the one or more second subcarriers, wherein the one or more first subcarrier frequencies and the one or more second subcarrier frequencies are located within a carrier band having a same estimate of channel state information, and wherein said transmitting and said receiving occur at least in part temporally simultaneously.
2. The method of claim 1 , wherein said transmit signals comprise an uplink transmission and wherein said receive signals comprise a downlink transmission.
3. The method of claim 1 , wherein the first communication device comprises a wireless base station, and wherein the second communication device comprises a user device.
4. The method of claim 1 , wherein said receiving the receive signals comprises calculating weights used to combine information from multiple antennas, and wherein the weights are associated, at least in part, with an estimate of channel state information between the first communication device and the second communication device.
5. The method of claim 4 , wherein said transmitting the transmit signals comprises using the weights to form a beam using the multiple antennas.
6. The method of claim 1 , wherein a number of the one or more first subcarrier frequencies is different than a number of the one or more second subcarrier frequencies.
7. The method of claim 1 , wherein said transmitting the transmit signals comprises encoding data for the transmit signals in accordance with orthogonal frequency division multiplexing (OFDM) using the first subcarrier frequencies.
8. The method of claim 1 , wherein said receiving the receive signals comprises at least partially cancelling interference at each antenna used to receive the receive signals due to a portion of the transmit signals provided by that same antenna.
9. The method of claim 8 , wherein said receiving the receive signals comprises at least partially cancelling interference at each antenna used to receive the receive signals due to a portion of the transmit signals provided by that same antenna and other antennas used to provide the transmit signals.
10. The method of claim 1 , wherein said transmitting the transmit signals and said receiving the receive signals further comprise using time division duplexing techniques.
11. A system comprising:
an antenna array comprising a plurality of antennas;
respective transceivers in communication with each of the plurality of antennas; and
a weight processor in communication with the respective transceivers and configured to calculate weights for the plurality of antennas based on receive signals received at the plurality of antennas, wherein the receive signals are received in first subcarrier frequencies; and
wherein the respective transceivers are configured to use the weights to transmit signals using the antenna array in a second subcarrier frequencies, wherein the first subcarrier frequencies are each different than the second subcarrier frequencies.
12. The system of claim 11 , wherein the plurality of antennas are distributed in an environment to form a distributed antenna system.
13. The system of claim 11 , wherein the plurality of antennas are incorporated in a single communication device.
14. The system of claim 11 , wherein the receive signals are configured to be received from and the transmit signals are configured to be provided to a communication device, and wherein the weights are associated with an estimate of channel state information between the communication device and the antenna array.
15. The system of claim 14 , wherein the system comprises a user device and the communication device comprises a base station.
16. The system of claim 11 , wherein a number of the first subcarrier frequencies is different than a number of the second subcarrier frequencies.
17. The system of claim 11 , wherein the first subcarrier frequencies and the second subcarrier frequencies are located within a carrier band having a same estimate of channel state information.
18. The system of claim 11 , further comprising a beamforming network and a baseband radio configured to encode data for the transmit signals in accordance with orthogonal frequency division multiplexing (OFDM) using the second subcarrier frequencies.
19. The system of claim 18 , wherein the beamforming network and the baseband radio are further configured to encode date for the transmit signals using time division duplexing techniques.
20. The system of claim 11 , further comprising interference cancellation circuitry included in the respective transceivers, the interference cancellation circuitry configured to at least partially cancel interference at each antenna used to receive the receive signals due to a portion of the transmit signals provided by that same antenna.
21. The system of claim 20 , wherein the interference cancellation circuitry is further configured to at least partially cancel interference at each antenna used to receive the receive signals due to other antennas used to provide the transmit signals.