Method, apparatus and computer program product providing soft iterative recursive least squares (RLS) channel estimator

• US 8,327,219 B2
• Filed: 11/09/2011
• Issued: 12/04/2012
• Est. Priority Date: 05/16/2006
• Status: Active Grant

• Current Assignee: Conversant Wireless Licensing S.à.r.l. (f/k/a Core Wireless Licensing S.a.r.l.) (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Original Assignee: Conversant Wireless Licensing S.à.r.l. (f/k/a Core Wireless Licensing S.a.r.l.) (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Inventors: Kim, Kyeong Jin
• Primary Examiner(s): ABRAHAM, ESAW T
• Application Number:
  US13/292,540
• Publication Number:
  US 20120054577A1
• Time in Patent Office: 391 Days
• Field of Search: 714/752, 714/755, 714/758, 714/799, 365/340, 375/340
• US Class Current: 714/755
• CPC Class Codes: H03M 13/1148 Structural properties of the code parity-check or generator matrix
• CPC Class Codes: H03M 13/2972 Serial concatenation using convolutional component codes

Abstract

Disclosed is an apparatus having a detector for an iterative LDPC-coded MIMO-OFDM system, where the detector is configured to use a structured irregular LDPC code in conjunction with a belief propagation algorithm. Also disclosed is an apparatus having a detector for a structured irregular LDPC-coded MIMO-OFDM system, where the detector is configured to use an iterative Recursive Least Squares-based data detection and channel estimation technique. Corresponding methods and computer program products are also disclosed.

Claims

1. A method, comprising:

detecting a received signal for one of a structured irregular low-density parity-check (LDPC) code multiple-input-multiple-output (MIMO) orthogonal frequency division multiplex (OFDM) system and an iterative LDPC-coded MIMO-OFDM system; and

iteratively determining an extrinsic output for the received signal at a channel decoder based on a current a posteriori probability (APP), such that each iteration comprises;

determining the current APP at a soft data detector based at least in part on a prior extrinsic output from the channel decoder and a soft channel estimate from an iterative Recursive Least Squares-based channel estimator, the prior extrinsic output and the soft channel estimate each determined based on a prior APP.

2. The method of claim 1, where the iterative Recursive Least Squares-based channel estimator is suitable for use over a quasi static channel.

3. The method of claim 1, wherein determining the extrinsic output comprises decoding the current APP using a belief propagation algorithm in order to generate soft bit information.

4. The method of claim 3, wherein the belief propagation algorithm is a layered belief propagation algorithm.

5. An apparatus, comprising:

a soft data detector configured to detect a received signal for at least one of a structured irregular low-density parity-check (LDPC) coded multiple-input-multiple-output (MIMO) orthogonal frequency division multiplex (OFDM) system and an iterative LDPC-coded MIMO-OFDM system;

an iterative Recursive Least Squares-based channel estimator configured to determine a soft channel estimate; and

a channel decoder configured to iteratively determine an extrinsic output for the received signal based on a current a posteriori probability (APP),

whererin for each iteration, the current APP is determined at the soft data detector based at least in part on a prior extrinsic output from the channel decoder and a soft channel estimate from the iterative Recursive Least Squares-based channel estimator, the prior extrinsic output and the soft channel estimate each determined based on a prior APP.

6. The apparatus of claim 5, where the iterative Recursive Least Squares-based channel estimator is suitable for use over a quasi static channel.

7. The apparatus of claim 5, embodied at least in part in an integrated circuit.

8. The apparatus of claim 5, wherein the channel decoder is configured to determine the extrinsic output by decoding the current APP using a belief propagation algorithm in order to generate soft bit information.

9. The apparatus of claim 8, wherein the belief propagation algorithm is a layered belief propagation algorithm.

10. A computer program product comprising instructions embodied in a tangible data storage medium, execution of the instructions by a data processor resulting in an operation of:

detecting a received signal for one of a structured irregular low-density parity-check (LDPC) coded multiple-input-multiple-output (MIMO) orthogonal frequency division multiplex (OFDM) system and an iterative LDPC-coded MIMO-OFDM system; and

iteratively determining an extrinsic output for the received signal at a channel decoder based on a current a posteriori probability (APP), such that each iteration comprises;

determining the current APP at a soft data detector based at least in part on a prior extrinsic output from the channel decoder and a soft channel estimate from an iterative Recursive Least Squares-based channel estimator, the prior extrinsic output and the soft channel estimate each determined based on a prior APP.

11. The computer program product of claim 10, where the iterative Recursive Least Squares-based channel estimator is suitable for use over a quasi static channel.

12. The computer program product of claim 10, wherein determining the extrinsic output comprises decoding the current APP using a belief propagation algorithm in order to generate soft bit information.

13. The computer program product of claim 12, wherein the belief propagation algorithm is a layered belief propagation algorithm.