Hybrid beam former
In certain aspects of the present disclosure, an apparatus for wireless communications is provided. The apparatus comprises a plurality of block circuits, wherein each one of the plurality of block circuits is configured to receive a respective plurality of signals from a respective subset of antenna elements of an antenna array. Each one of the plurality of block circuits comprises a respective plurality of phase shifters configured to shift phases of the respective plurality of signals to obtain a respective plurality of phase-shifted signals, and a respective combiner configured to combine the respective plurality of phase-shifted signals into a respective combined signal. The apparatus also comprises a plurality of time-delay elements configured to delay the combined signals to obtain a plurality of delayed combined signals, and a combiner configured to combine the plurality of delayed combined signals into a total combined signal.
1. An apparatus for wireless communications, comprising:
a plurality of block circuits, wherein each one of the plurality of block circuits is configured to receive a respective plurality of signals from a respective subset of antenna elements of an antenna array, and each one of the plurality of block circuits comprises:
a respective plurality of phase shifters configured to shift phases of the respective plurality of signals to obtain a respective plurality of phase-shifted signals; and
a respective combiner configured to combine the respective plurality of phase-shifted signals into a respective combined signal;
a plurality of time-delay elements configured to delay the combined signals to obtain a plurality of delayed combined signals; and
a combiner configured to combine the plurality of delayed combined signals into a total combined signal.
2. The apparatus of claim 1 , wherein, for each one of the plurality of block circuits, the respective plurality of phase shifters is configured to shift the phases of the respective plurality of signals by a set of phase shift values associated with a receive beam direction of the antenna array.
3. The apparatus of claim 2 , wherein the plurality of time-delay elements is configured to delay the combined signals by a set of time delay values associated with the receive beam direction of the antenna array.
4. The apparatus of claim 2 , wherein the receive beam direction is directed towards a wireless node, and each one of the plurality of block circuits is configured to receive the respective plurality of signals from the wireless node via the respective subset of the antenna elements of the antenna array.
5. The apparatus of claim 1 , further comprising at least one radio frequency (RF) chain configured to receive the total combined signal and to perform at least one of frequency down conversion of the total combined signal, analog-to-digital conversion of the total combined signal, or demodulation of the total combined signal.
6. The apparatus of claim 1 , wherein each one of the plurality of time-delay elements comprises a continuous adjustable delay element or a discrete adjustable delay element.
7. A wireless node, comprising:
an antenna array comprising antenna elements;
a plurality of block circuits, wherein each one of the plurality of block circuits is configured to receive a respective plurality of signals from another wireless node via a respective subset of the antenna elements of the antenna array, and each one of the plurality of block circuits comprises:
a respective plurality of phase shifters configured to shift phases of the respective plurality of signals to obtain a respective plurality of phase-shifted signals; and
a respective combiner configured to combine the respective plurality of phase-shifted signals into a respective combined signal;
a plurality of time-delay elements configured to delay the combined signals to obtain a plurality of delayed combined signals; and
a combiner configured to combine the plurality of delayed combined signals into a total combined signal.
8. A method for wireless communications, comprising:
for each one of a plurality of subsets of antenna elements of an antenna array,
receiving a respective plurality of signals from the respective one of the plurality of subsets of the antenna elements of the antenna array;
shifting phases of the respective plurality of signals to obtain a respective plurality of phase-shifted signals; and
combining the respective plurality of phase-shifted signals into a respective combined signal;
delaying the combined signals to obtain a plurality of delayed combined signals; and
combining the plurality of delayed combined signals into a total combined signal.
9. The method of claim 8 , wherein, for each one of the plurality of subsets of the antenna elements of the antenna array, shifting the phases of the respective plurality of signals comprises shifting the phases of the respective plurality of signals by a set of phase shift values associated with a receive beam direction of the antenna array.
10. The method of claim 9 , wherein delaying the combined signals comprises delaying the combined signals by a set of time delay values associated with the receive beam direction of the antenna array.
11. The method of claim 9 , wherein the receive beam direction is directed towards a wireless node, and, for each one of the plurality of subsets of the antenna elements of the antenna array, receiving the respective plurality of signals comprises receiving the respective plurality of signals from the wireless node via the respective one of the plurality of subsets of the antenna elements of the antenna array.
12. The method of claim 8 , further comprising performing at least one of frequency down conversion of the total combined signal, analog-to-digital conversion of the total combined signal, or demodulation of the total combined signal.