Radio telecommunications receiver operative to receive digital data symbols or bits by iterative determination of soft estimates, and a corresponding method

• US 20030154435A1
• Filed: 02/14/2003
• Published: 08/14/2003
• Est. Priority Date: 02/14/2002
• Status: Active Grant

• Current Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Claussen, Holger, Karimi, Hamid Reza
• Granted Patent: US 7,212,579 B2
• Time in Patent Office: Days
• US Class Current: 714/755
• CPC Class Codes: H04L 1/005 Iterative decoding, including iteration between signal detection and decoding operation
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0656 Cyclotomic systems, e.g. Bell Labs Layered Space-Time [BLAST]
• CPC Class Codes: H04L 25/03171 Arrangements involving maximum a posteriori probability [MAP] detection

Abstract

A radio telecommunications receiver operates to receive digital data symbols or bits by iterative determination of soft estimates of symbols or bits followed by a hard decision as to what symbol or bit was intended. The receiver comprises a first processor operative to provide first soft estimates of symbols or bits, of the received signal and a second processor operative to decode the first soft estimates and to provide second soft estimates of the symbols or bits. The receiver also comprises a combiner operative to provide third soft estimates back to the first processor for subsequent further decoding, the third soft estimates of each symbol or bit being dependent upon the respective second soft estimate and a respective previous second soft estimate.

Claims

1. A radio telecommunications receiver operative to receive symbols or bits by iterative determination of soft estimates of symbols or bits followed by a hard decision as to what symbol or bit was intended, the receiver comprising:

a first processor operative to provide first soft estimates of symbols or bits of the received signal;

a second processor operative to decode the first soft estimates and to provide second soft estimates of the symbols or bits;

a combiner operative to provide third soft estimates back to the first processor for subsequent further decoding, the third soft estimates of each symbol or bit being dependent upon the respective second soft estimate and a respective previous second soft estimate.

2. The receiver of claim 1, wherein, a plurality of iterations each involving the first processor, second processor and combiner are performed whereupon a hard decision is made as to what symbol or bit was intended.

3. The receiver of claim 1, wherein, the first processor is a successive interference cancellation SIC multiple input multiple output MIMO detector;

the second processor is a convolutional decoder, turbo-decoder, or decoder of concatenated codes; and

the soft estimates are log likelihood ratios.

4. The receiver of claim 3, wherein, the SIC MIMO detector undertakes detection on a per-bit basis by successive interference cancellation.

5. The receiver of claim 3, wherein, the first soft estimates from SIC MIMO detector, are deinterleaved by a deinterleaver before being passed to the second processor, and the third soft estimates provided by the combiner are interleaved by an interleaver before being passed back to the SIC MIMO detector.

6. The receiver of claim 1, wherein, the first processor is a convolutional decoder, turbo-decoder, or decoder of concatenated codes;

the second processor is a convolutional decoder, turbo-decoder, or decoder of concatenated codes; and

the soft estimates are extrinsic information values.

7. The receiver of claim 1, further comprising:

a second combiner operative to provide adapted first soft estimates to the second processor, the adapted first soft estimates of each symbol being dependent upon the respective first soft estimate and a respective previous first soft estimate.

8. The receiver of claim 1, wherein, the combiner is also operative to provide adapted first soft estimates to the second processor, the adapted first soft estimates of each symbol or bit being dependent upon the respective first soft estimate and respective previous first soft estimate.

9. A method of receiving symbols or bits in a radio telecommunications receiver by iterative determination of soft estimates of symbols or bits followed by a hard decision as to what symbol or bit was intended, the method comprising the steps of:

processing the received signal to provide first soft estimates of symbols or bits of the received signal,

decoding the first soft estimates to provide second soft estimates of the symbols or bits,

producing third soft estimates dependent upon the second soft estimate and a previous second soft estimate of each symbol or bit, and

providing the third soft estimates back to the first processor for subsequent further decoding.