METHOD AND APPARATUS FOR MULTIBAND PREDISTORTION USING TIME-SHARED ADAPTATION LOOP

• US 20160285485A1
• Filed: 03/23/2016
• Published: 09/29/2016
• Est. Priority Date: 03/26/2015
• Status: Abandoned Application

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Fehri, Bilel, Boumaiza, Slim
• Application Number:
  US15/078,801
• Publication Number:
  US 20160285485A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/62 for providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio
• CPC Class Codes: H04B 2001/0425 with linearisation using predistortion

Abstract

Systems and methods for providing multiband predistortion using a time-shared adaptation loop are disclosed. In some embodiments, a multiband predistortion system includes a multiband power amplifier for amplifying N separate bands, a predistortion system including N Digital Predistorters (DPDs), and a single adaptation loop capable of providing predistorter adaptation for the N separate bands. The single adaptation loop includes at least one Training Engine (TE) module where the number of TE modules is less than N, and at least one Transmission Observation Receiver (TOR) module where the number of TOR modules is less than N. In this way, the cost and complexity of the multiband predistortion system can be reduced.

Claims

1. A multiband predistortion system comprising:

a multiband or broadband power amplifier for amplifying N separate bands;

a predistortion system comprising N Digital Predistorters (DPDs); and

a single adaptation loop capable of providing predistorter adaptation for the N separate bands, comprising;

at least one Training Engine (TE) module, where the number of TE modules is less than N; and

at least one Transmission Observation Receiver (TOR) module, where the number of TOR modules is less than N.

2. The multiband predistortion system of claim 1 wherein:

the N separate bands are N Component Carriers (CCs) of a carrier aggregated signal;

the single adaptation loop is shared by the N CCs; and

the N DPDs are trained selectively as determined by a band selection module.

3. The multiband predistortion system of claim 2 wherein an order of adaptation of the N DPDs is configurable through the band selection module.

4. The multiband predistortion system of claim 2 wherein an order of adaptation of the N DPDs is sequential.

5. The multiband predistortion system of claim 2 wherein an order of adaptation of the N DPDs is based on an error vector magnitude (EVM) performance in each of the N separate bands.

6. The multiband predistortion system of claim 2 wherein an order of adaptation of the N DPDs is based on an adjacent channel leakage ratio (ACLR) performance in each of the N separate bands.

7. The multiband predistortion system of claim 2 wherein an order of adaptation of the N DPDs is based on a normalized mean square error (NMSE) performance in each of the N separate bands.

8. The multiband predistortion system of claim 7 wherein the single adaptation loop further comprises a single Basis Function Generator (BFG) module which generates N sets of basis functions for both a forward path of the multiband predistortion system and an adaptation path of the multiband predistortion system.

9. The multiband predistortion system of claim 7 wherein the single adaptation loop further comprises:

a first Basis Function Generator (BFG) module which generates N sets of basis functions for a forward path of the multiband predistortion system; and

a second BFG module which generates N sets of basis functions for an adaptation path of the multiband predistortion system.

10. The multiband predistortion system of claim 9 wherein the single adaptation loop implements an efficient multiband iterative algorithm in the TE module.

11. The multiband predistortion system of claim 10 wherein the efficient multiband iterative algorithm is a recursive least squares (RLS) algorithm.

12. The multiband predistortion system of claim 11 wherein the single adaptation loop uses a Model-Reference Adaptive Control (MRAC) learning approach.

13. The multiband predistortion system of claim 12 wherein a required amount of feedback information is less than a required amount of feedback information for a multiband predistortion system with N TOR modules.

14. The multiband predistortion system of claim 13 wherein a required amount of feedback information is less than a required amount of feedback information for a multiband predistortion system with N TE modules.

15. The multiband predistortion system of claim 14 wherein N equals two.

16. The multiband predistortion system of claim 15 wherein the single adaptation loop implements an iterative dual-band estimator in the single TE module.

17. The multiband predistortion system of claim 14 wherein N is greater than two.

18. The multiband predistortion system of claim 17 wherein each band of the N separate bands is a Long Term Evolution (LTE) band.

19. The multiband predistortion system of claim 17 wherein each band of the N separate bands is a Wideband Code Division Multiple Access (WCDMA) band.

20. The multiband predistortion system of claim 17 wherein at least two bands of the N separate bands are bands of different Radio Access Technologies (RATs).