Apparatus and method of harmonic interference cancellation
A baseband chip may include a transmitter configured to transmit a first signal. The baseband chip may also include a receiver configured to receive a second signal that includes a receive signal portion and a harmonic interference portion leaked from the transmitter. The baseband chip may further include a harmonic model block configured to multiply a first output from a first harmonic model associated with an amplitude modulation phase modulation (AMPM) look-up table (LUT) and a second output of a second harmonic model associated with an AMAM LUT to generate a third output. The harmonic model block may be further configured to estimate the harmonic interference portion based at least in part on the third output. The baseband chip may also include an interference cancellation block configured to cancel the harmonic interference portion from the second signal to obtain the receive signal portion.
1. A baseband chip, comprising:
a transmitter configured to transmit a first signal;
a receiver configured to receive a second signal, the first signal and the second signal being transmitted and received concurrently via carrier aggregation (CA), the second signal including a receive signal portion and a harmonic interference portion, the harmonic interference portion being associated with a leakage of the first signal to the receiver;
a harmonic model block configured to:
multiply a first output from a first harmonic model associated with an amplitude modulation phase modulation (AMPM) look-up table (LUT) and a second output of a second harmonic model associated with an amplitude modulation amplitude modulation (AMAM) LUT to generate a third output; and
estimate the harmonic interference portion based at least in part on the third output; and
an interference cancellation block configured to cancel the harmonic interference portion from the second signal to obtain the receive signal portion,
wherein the harmonic model block is further configured to:
determine an order of the harmonic interference portion;
select, based at least in part on the order of the harmonic interference portion, the first harmonic model from the AMPM LUT that models transmission envelope as a function of a harmonic phase shift; and
select, based at least in part on the order of the harmonic interference portion, the second harmonic model from the AMAM LUT that models transmission envelope as a function of a magnitude of a harmonic interference envelope, the harmonic interference envelope being associated with the order of the harmonic interference portion.
2. The baseband chip of claim 1 , wherein the first harmonic model models transmission envelope as the function of the harmonic phase shift without interpolation.
3. The baseband chip of claim 1 , wherein the harmonic model block includes a gain block configured to:
determine the magnitude of the harmonic interference envelope changed with respect to a power amplifier of the transmitter; and
input information associated with the magnitude of the harmonic interference envelope associated with the harmonic interference portion into the second harmonic model to determine the harmonic interference envelope,
wherein the magnitude of the harmonic interference envelope being the second output of the second harmonic model.
4. The baseband chip of claim 3 , wherein the harmonic model block includes an AMAM filter configured to:
filter dispersion from the third output to generate a fourth output,
wherein the dispersion is associated with an antenna mismatch of the transmitter and receiver, and
wherein the fourth output is the estimated harmonic interference portion.
5. The baseband chip of claim 4 , wherein the harmonic model block includes a delay block configured to:
align the receive signal portion and the harmonic interference portion of the second signal.
6. The baseband chip of claim 5 , wherein the harmonic model block is further configured to:
subtract a phase of the first signal raised to a power of the order of the harmonic interference portion subtracted from a phase shift associated with the order of the harmonic interference portion.
7. A baseband chip, comprising:
a transmitter configured to transmit a first signal;
a receiver configured to receive a second signal, the first signal and the second signal being transmitted and received concurrently via carrier aggregation (CA), the second signal including a receive signal portion and a harmonic interference portion, the harmonic interference portion being associated with a leakage of the first signal to the receiver;
a memory; and
at least one processor coupled to the memory and configured to:
multiply a first output from a first harmonic model associated with an amplitude modulation phase modulation (AMPM) look-up table (LUT) and a second output of a second harmonic model associated with an amplitude modulation amplitude modulation (AMAM) LUT to generate a third output;
estimate the harmonic interference portion based at least in part on the third output; and
cancel the harmonic interference portion from the second signal to obtain the receive signal portion,
wherein the at least one processor is further configured to:
determine an order of the harmonic interference portion;
select, based at least in part on the order of the harmonic interference portion, the first harmonic model from the AMPM LUT that models transmission envelope as a function of a harmonic phase shift; and
select, based at least in part on the order of the harmonic interference portion, the second harmonic model from the AMAM LUT that models transmission envelope as a function of a magnitude of a harmonic interference envelope, the harmonic interference envelope being associated with the order of the harmonic interference portion.
8. The baseband chip of claim 7 , wherein the AMPM LUT models transmission envelope as the function of the harmonic phase shift without interpolation.
9. The baseband chip of claim 7 , wherein the at least one processor is further configured to:
determine the magnitude of the harmonic interference envelope changed with respect to a power amplifier of the transmitter; and
input information associated with the magnitude of the harmonic interference envelope associated with the harmonic interference portion into the second harmonic model to determine the harmonic interference envelope,
wherein the magnitude of the harmonic interference envelope being the second output of the second harmonic model.
10. The baseband chip of claim 9 , wherein the at least one processor is further configured to:
filter dispersion from the third output to generate a fourth output,
wherein the dispersion is associated with an antenna mismatch of the transmitter and receiver, and
wherein the fourth output is the estimated harmonic interference portion.
11. The baseband chip of claim 10 , wherein the at least one processor is further configured to:
align the receive signal portion and the harmonic interference portion of the second signal.
12. The baseband chip of claim 11 , wherein the at least one processor is further configured to:
subtract a phase of the first signal raised to a power of the order of the harmonic interference portion subtracted from a phase shift associated with the order of the harmonic interference portion.
13. A method of wireless communication, comprising:
transmitting, by a transmitter, a first signal;
receiving, by a receiver, a second signal, the first signal and the second signal being transmitted and received concurrently via carrier aggregation (CA), the second signal including a receive signal portion and a harmonic interference portion, the harmonic interference portion being associated with a leakage of the first signal to the receiver;
multiplying a first output from a first harmonic model associated with an amplitude modulation phase modulation (AMPM) look-up table (LUT) and a second output of a second harmonic model associated with an amplitude modulation amplitude modulation (AMAM) LUT to generate a third output;
estimating the harmonic interference portion based at least in part on the third output;
cancelling the harmonic interference portion from the second signal to obtain the receive signal portion;
determining an order of the harmonic interference portion;
selecting, based at least in part on the order of the harmonic interference portion, the first harmonic model from the AMPM LUT that models transmission envelope as a function of a harmonic phase shift; and
selecting, based at least in part on the order of the harmonic interference portion, the second harmonic model from the AMAM LUT that models transmission envelope as a function of a magnitude of a harmonic interference envelope, the harmonic interference envelope being associated with the order of the harmonic interference portion.
14. The method of claim 13 , wherein the AMPM LUT models transmission envelope as the function of the harmonic phase shift without interpolation.
15. The method of claim 13 , further comprising
determining the magnitude of the harmonic interference envelope changed with respect to a power amplifier of the transmitter; and
inputting information associated with the magnitude of the harmonic interference envelope associated with the harmonic interference portion into the second harmonic model to determine the harmonic interference envelope,
wherein the magnitude of the harmonic interference envelope being the second output of the second harmonic model.
16. The method of claim 15 , further comprising:
filtering dispersion from the third output to generate a fourth output,
wherein the dispersion is associated with an antenna mismatch of the transmitter and receiver, and
wherein the fourth output is the estimated harmonic interference portion.
17. The method of claim 16 , further comprising:
aligning the receive signal portion and the harmonic interference portion of the second signal.