Efficient implementation of hybrid beamforming
Hybrid beamforming may be configured for wireless communication systems (e.g., multiple-input multiple output (MIMO) and/or massive-MIMO). The implementation(s) may determine a number of radio frequency (RF) chains for realizing a fully digital precoder (FDP) in a structure (e.g., a hybrid analog/digital precoder). The number of RF chains may be less than a number of transmitter antennas. A transmit vector signal may be determined based on a digital precoder and an input symbol vector. An analog precoder and/or a baseband signal may be determined based on the determined transmit vector signal. The number of RF chains may be determined based on the determined baseband signal. The baseband signal may be fed to the determined number of RF chains. The analog precoder may determine a beamforming signal based on an output of the determined number of RF chains. The analog precoder may transmit the beamforming signal using the number of transmitter antennas.
1. A device comprising:
a processor configured to:
receive data to be transmitted, the data comprising an input symbol vector;
determine a transmit vector signal based on a digital precoder and the input symbol vector;
determine a maximum absolute value of the transmit vector signal;
determine an analog precoder based on the determined maximum absolute value of the transmit vector signal;
determine a baseband signal based on the determined transmit vector signal;
determine a number of radio frequency (RF) chains based on the determined baseband signal, wherein the number of RF chains is less than a number of transmitter antennas;
feed the baseband signal to the determined number of RF chains;
determine a beamforming signal based on the determined analog precoder and an output of the determined number of RF chains; and
transmit the determined beamforming signal using the number of transmitter antennas.
2. The device of claim 1 , wherein the number of RF chains is set to one RF chain.
3. The device of claim 2 , wherein the number of RF chains is set to one RF chain on a condition that the determined baseband signal is a complex number.
4. The device of claim 1 , wherein the number of RF chains is set to two RF chains.
5. The device of claim 4 , wherein the number of RF chains is set to two RF chains on a condition that the determined baseband signal is a real number.
6. The device of claim 1 , wherein to determine the baseband signal, the processor is configured to:
determine the baseband signal based on the determined maximum absolute value of the transmit vector signal.
7. A method comprising:
receiving data to be transmitted, the data comprising an input symbol vector;
determining a transmit vector signal based on a digital precoder and the input symbol vector;
determining a maximum absolute value of the transmit vector signal;
determining an analog precoder based on the determined maximum absolute value of the transmit vector signal;
determining a baseband signal based on the determined transmit vector signal;
determining a number of radio frequency (RF) chains based on the determined baseband signal, wherein the number of RF chains is less than a number of transmitter antennas;
feeding the baseband signal to the determined number of RF chains;
determining a beamforming signal based on the determined analog precoder and an output of the determined number of RF chains; and
transmitting the determined beamforming signal using the number of transmitter antennas.
8. The method of claim 7 , wherein the number of RF chains is set to one RF chain.
9. The method of claim 8 , wherein the number of RF chains is set to one RF chain on a condition that the determined baseband signal is a complex number.
10. The method of claim 7 , wherein the number of RF chains is set to two RF chains.
11. The method of claim 10 , wherein the number of RF chains is set to two RF chains on a condition that the determined baseband signal is a real number.
12. The method of claim 7 , wherein determining the baseband signal comprises:
determining the baseband signal based on the determined maximum absolute value of the transmit vector signal.
13. A device comprising:
a processor configured to:
receive data to be transmitted, the data comprising an input symbol vector;
determine a transmit vector signal based on a digital precoder and the input symbol vector;
determine an analog precoder based on the determined transmit vector signal;
determine a baseband signal based on the determined transmit vector signal;
determine a number of radio frequency (RF) chains based on the determined baseband signal, wherein the number of RF chains is less than a number of transmitter antennas, and wherein the number of RF chains is set to (i) one RF chain on a condition that the determined baseband signal is a complex number, or (ii) two RF chains on a condition that the determined baseband signal is a real number;
feed the baseband signal to the determined number of RF chains;
determine a beamforming signal based on the determined analog precoder and an output of the determined number of RF chains; and
transmit the determined beamforming signal using the number of transmitter antennas.
14. The device of claim 13 , wherein to determine the baseband signal, the processor is configured to:
determine a maximum absolute value of the transmit vector signal; and
determine the baseband signal based on the determined maximum absolute value of the transmit vector signal.
15. The device of claim 14 , wherein the number of RF chains is set to one RF chain.
16. The device of claim 14 , wherein the number of RF chains is set to two RF chains.
17. A method comprising:
receiving data to be transmitted, the data comprising an input symbol vector;
determining a transmit vector signal based on a digital precoder and the input symbol vector;
determining an analog precoder based on the determined transmit vector signal;
determining a baseband signal based on the determined transmit vector signal;
determining a number of radio frequency (RF) chains based on the determined baseband signal, wherein the number of RF chains is less than a number of transmitter antennas, and wherein the number of RF chains is set to (i) one RF chain on a condition that the determined baseband signal is a complex number, or (ii) two RF chains on a condition that the determined baseband signal is a real number;
feeding the baseband signal to the determined number of RF chains;
determining a beamforming signal based on the determined analog precoder and an output of the determined number of RF chains; and
transmitting the determined beamforming signal using the number of transmitter antennas.
18. The method of claim 17 , wherein determining the baseband signal comprises:
determining a maximum absolute value of the transmit vector signal; and
determining the baseband signal based on the determined maximum absolute value of the transmit vector signal.
19. The method of claim 18 , wherein the number of RF chains is set to one RF chain.
20. The method of claim 18 , wherein the number of RF chains is set to two RF chains.