Self interference noise cancellation to support multiple frequency bands
Examples described herein include systems and methods which include wireless devices and systems with examples of full duplex compensation with a self-interference noise calculator that compensates for the self-interference noise generated by power amplifiers at harmonic frequencies of a respective wireless receiver. The self-interference noise calculator may be coupled to antennas of a wireless device and configured to generate the adjusted signals that compensate self-interference. The self-interference noise calculator may include a network of processing elements configured to combine transmission signals into sets of intermediate results. Each set of intermediate results may be summed in the self-interference noise calculator to generate a corresponding adjusted signal. The adjusted signal is receivable by a corresponding wireless receiver to compensate for the self-interference noise generated by a wireless transmitter transmitting on the same or different frequency band as the wireless receiver is receiving.
1. A method comprising:
receiving, at a self-interference noise calculator, a first amplified signal associated with a first frequency and a second amplified signal associated with a second frequency, the first amplified signal provided to a first antenna of a plurality of antennas and the second amplified signal provided to a second antenna of the plurality of antennas;
processing the first and second amplified signals in accordance with a plurality of connection weights to generate a first adjustment signal based on at least self-interference noise of a corresponding path from the first antenna to the second antenna of the plurality of antennas, the self-interference noise associated with an interfering harmonic frequency of the first frequency, the plurality of connection weights between layers of processing elements of the self-interference noise calculator; and
compensating a first received signal received at a third antenna of the plurality of antennas with the first adjustment signal, the third antenna associated with the second frequency.
2. The method of claim 1 , further comprising:
amplifying a first transmit signal associated with the first frequency to generate the first amplified signal comprising first amplifier noise associated with the first frequency; and
amplifying a second associated with the second frequency to generate the second amplified signal comprising second amplifier noise associated with the second frequency.
3. The method of claim 2 , wherein the interfering harmonic frequency being generated when the first amplified signal is amplified, the interfering harmonic frequency being part of the first amplifier noise.
4. The method of claim 2 , wherein the interfering harmonic frequency is a second-order harmonic component of the first frequency.
5. The method of claim 4 , wherein the first frequency corresponds to 1.8 GHz in the 4G Long-Term Evolution (LTE) band, and wherein the second frequency corresponds to 3.5 GHz in the 5G New Radio (NR) band.
6. The method of claim 2 , further comprising:
generating an interfering difference frequency based partly on components of the first amplifier noise and the second amplifier noise, the interfering difference frequency being generated based on a harmonic component of the first frequency interfering with a harmonic component at the second frequency.
7. The method of claim 6 , wherein the interfering difference frequency is a difference of the second frequency from the first frequency.
8. The method of claim 6 , further comprising:
generating a second adjustment signal based on at least the interfering difference frequency; and
compensating a second received signal received at a fourth antenna of the plurality of antennas with the second adjustment signal, the fourth antenna associated with the first frequency.
9. The method of claim 8 , wherein compensating the second received signal received at the fourth antenna with the second adjustment signal comprises subtracting the second adjustment signal from the second received signal to generate a second compensated received signal.
10. The method of claim 1 , wherein compensating the first received signal received at the third antenna with the first adjustment signal comprises subtracting the first adjustment signal from the first received signal to generate a first compensated received signal.
11. The method of claim 1 , further comprising:
adjusting a first group of the plurality of antennas, including the second antenna, associated with the second frequency to point directionally towards a device receiving at the second frequency.
12. The method of claim 11 , wherein the first group of the plurality of antennas supports a first massive MIMO connection with the device receiving at the second frequency.
13. The method of claim 12 , wherein a second group of the plurality of antennas is associated with first frequency and supports a second massive MIMO connection with the device receiving at the first frequency.
14. The method of claim 12 , wherein the first massive MIMO connection is with a vehicle, and wherein the second massive MIMO connection is with a drone.
15. The method of claim 11 , further comprising:
detecting that the device receiving at the second frequency has entered a geographical coverage area.