Granted Patent B2

US 12,334,964 · App. 17/877,441 · Granted Jun 17, 2025

Inventors: Tomoya Ota (Kawasaki, JP); Hiroyoshi Ishikawa (Kawasaki, JP)

Assignee: FUJITSU LIMITED

H04B1/0483H04B1/0475H04B2001/0433

Abstract

Claims (31)

1. A wireless communication apparatus comprising:

a plurality of antenna elements;

a plurality of power amplifiers provided in the plurality of antenna elements;

a processor that outputs a transmission signal to the plurality of power amplifiers; and

a plurality of feedback paths each of which allows a feedback signal to be fed back from the plurality of power amplifiers to the processor, wherein the processor executes a process comprising:

collectively correcting variations in analog characteristics exhibited in the plurality of feedback paths, and

updating, by using the transmission signal and the feedback signal that are obtained by being corrected, a distortion compensation coefficient that is used to compensate nonlinear distortion produced in the plurality of power amplifiers.

2. The wireless communication apparatus according to claim 1 , wherein the collectively correcting includes collectively correcting the variations related to at least one of gain, delay, phase, and frequency characteristics exhibited in the plurality of feedback paths.

3. The wireless communication apparatus according to claim 1 , wherein the processor further executes a process comprising:

estimating the analog characteristics exhibited in the plurality of feedback paths; and

calculating a filter coefficient that is used to collectively correct the estimated analog characteristics.

4. The wireless communication apparatus according to claim 3 , wherein the calculating includes calculating a path based filter coefficient associated with each of the analog characteristics exhibited in the respective plurality of feedback paths, and

calculating a batch filter coefficient by obtaining a sum of the path based filter coefficients.

5. The wireless communication apparatus according to claim 1 , wherein the collectively correcting includes adding, to the transmission signal, a same characteristic as the analog characteristics exhibited in the plurality of feedback paths.

6. The wireless communication apparatus according to claim 1 , wherein the collectively correcting includes adding, to the feedback signal, an inverse characteristic of the analog characteristics exhibited in the plurality of feedback paths.

7. The wireless communication apparatus according to claim 1 , wherein the collectively correcting includes

performing correction on the feedback signal regarding an average amount of the analog characteristics exhibited in the plurality of feedback paths, and

performing correction on the transmission signal regarding a variation amount excluding the average amount.

8. The wireless communication apparatus according to claim 1 , wherein the processor further executes a process comprising:

calculating, from the transmission signal and the feedback signal that is associated with each of the plurality of feedback paths, a path based filter coefficient associated with each of the analog characteristics exhibited in the respective plurality of feedback paths by using a convergence algorithm; and

calculating a batch filter coefficient by obtaining a sum of the path based filter coefficients.

9. The wireless communication apparatus according to claim 1 , wherein the processor further executes a process comprising:

calculating, for each direction of a transmission beam, a filter coefficient that is used to collectively correct the analog characteristics exhibited in the plurality of feedback paths; and

storing the calculated filter coefficient in an associated manner with the direction of the transmission beam.

10. A distortion compensation method performed by a wireless communication apparatus that includes

a plurality of antenna elements,

a plurality of power amplifiers provided in the plurality of antenna elements,

a processor that outputs a transmission signal to the plurality of power amplifiers, and

a plurality of feedback paths each of which allows a feedback signal to be fed back from the plurality of power amplifiers to the processor, the distortion compensation method comprising:

collectively correcting variations in analog characteristics exhibited in the plurality of feedback paths, and

updating, by using the transmission signal and the feedback signal that are obtained by being corrected, a distortion compensation coefficient that is used to compensate nonlinear distortion produced in the plurality of power amplifiers.

Assignments (2)

Priority Claims (1)

Continuity (1)

References Cited (21)