Mixed signal low noise interference cancellation
RF communication systems with interference cancellation for coexistence are provided herein. In certain embodiments, a method of interference cancellation includes filtering a radio frequency (RF) transmit signal to generate a first RF feedback signal using a first filter of a front end system, filtering the RF transmit signal to generate a second RF feedback signal using a second filter of the front end system, processing the first RF feedback signal to generate a first digital interference cancellation signal using a first feedback receiver, processing the second RF feedback signal to generate a second digital interference cancellation signal using a second feedback receiver, and compensating an RF receive signal for interference based on the first digital interference cancellation signal and the second digital interference cancellation signal using a receiver.
1. A wireless device comprising:
a transmitter configured to generate a radio frequency transmit signal;
a front end system configured to receive the radio frequency transmit signal, the front end system including a first filter configured to filter the radio frequency transmit signal to generate a first radio frequency feedback signal, and a second filter configured to filter the radio frequency transmit signal to generate a second radio frequency feedback signal;
a first feedback receiver configured to process the first radio frequency feedback signal to generate a first digital interference cancellation signal;
a second feedback receiver configured to process the second radio frequency feedback signal to generate a second digital interference cancellation signal; and
a receiver configured to receive a radio frequency receive signal, the receiver further configured to compensate the radio frequency receive signal for interference based on the first digital interference cancellation signal and the second digital interference cancellation signal.
2. The wireless device of claim 1 wherein the first feedback signal provides harmonic feedback.
3. The wireless device of claim 2 wherein the second feedback signal provides adjacent channel leakage ratio feedback.
4. The wireless device of claim 1 wherein the first filter senses a first portion of frequency spectrum of the radio frequency transmit signal and the second filter senses a second portion of frequency spectrum of the radio frequency transmit signal.
5. The wireless device of claim 4 wherein the first filter and the second filter each filter a carrier frequency of the radio frequency transmit signal.
6. The wireless device of claim 1 wherein the radio frequency transmit signal and the radio frequency receive signal are different types of radio frequency signals.
7. The wireless device of claim 6 wherein the radio frequency transmit signal is a fourth generation signal and the radio frequency receive signal is a wireless local area network signal.
8. The wireless device of claim 6 wherein the radio frequency transmit signal is a fifth generation signal and the radio frequency receive signal is a wireless local area network signal.
9. The wireless device of claim 6 wherein the radio frequency receive signal is a fourth generation signal and the radio frequency transmit signal is a wireless local area network signal.
10. The wireless device of claim 6 wherein the radio frequency receive signal is a fifth generation signal and the radio frequency transmit signal is a wireless local area network signal.
11. The wireless device of claim 1 further comprising an antenna, the transmitter configured to provide the radio frequency transmit signal to the antenna through the front end system.
12. The wireless device of claim 1 wherein the front end system includes a power amplifier configured to amplify the radio frequency transmit signal, and a multi-throw switch including an input coupled to an output of the power amplifier, a first output coupled to the first filter, and a second output coupled to the second filter.
13. The wireless device of claim 1 wherein the first filter is a band pass filter and the second filter is a bulk acoustic wave filter.
14. A radio frequency communication system comprising:
a transmit front end circuit including a power amplifier configured to amplify a radio frequency transmit signal, a first filter configured to filter the radio frequency transmit signal to generate a first radio frequency feedback signal, and a second filter configured to filter the radio frequency transmit signal to generate a second radio frequency feedback signal;
a first feedback receiver configured to process the first radio frequency feedback signal to generate a first digital interference cancellation signal;
a second feedback receiver configured to process the second radio frequency feedback signal to generate a second digital interference cancellation signal; and
a receiver configured to receive a radio frequency receive signal, the receiver further configured to compensate the radio frequency receive signal for interference based on the first digital interference cancellation signal and the second digital interference cancellation signal.
15. The radio frequency communication system of claim 14 wherein the first feedback signal provides harmonic feedback.
16. The radio frequency communication system of claim 14 wherein the second feedback signal provides adjacent channel leakage ratio feedback.
17. The radio frequency communication system of claim 14 wherein the first filter is a band pass filter and the second filter is a bulk acoustic wave filter.
18. A method of interference cancellation in a wireless device, the method comprising:
filtering a radio frequency transmit signal to generate a first radio frequency feedback signal using a first filter of a front end system;
filtering the radio frequency transmit signal to generate a second radio frequency feedback signal using a second filter of the front end system;
processing the first radio frequency feedback signal to generate a first digital interference cancellation signal using a first feedback receiver;
processing the second radio frequency feedback signal to generate a second digital interference cancellation signal using a second feedback receiver; and
compensating a radio frequency receive signal for interference based on the first digital interference cancellation signal and the second digital interference cancellation signal using a receiver.
19. The method of claim 18 further comprising using the first feedback signal to provide harmonic feedback.
20. The method of claim 19 further comprising using the second feedback signal to provide adjacent channel leakage ratio feedback.