A Simple Approximation for the Bit-Interleaved Coded Modulation Capacity
Artikel i vetenskaplig tidskrift, 2014

The generalized mutual information (GMI) is an achievable rate for bit-interleaved coded modulation (BICM) and is highly dependent on the binary labeling of the constellation. The BICM-GMI, sometimes called the BICM capacity, can be evaluated numerically. This approach, however, becomes impractical when the number of constellation points and/or the constellation dimensionality grows, or when many different labelings are considered. A simple approximation for the BICM-GMI based on the area theorem of the demapper's extrinsic information transfer (EXIT) function is proposed. Numerical results show the proposed approximation gives good estimates of the BICM-GMI for labelings with close to linear EXIT functions, which includes labelings of common interest, such as the natural binary code, binary reflected Gray code, etc. This approximation is used to optimize the binary labeling of the 32-APSK constellation defined in the DVB-S2 standard. Gains of approximately 0.15 dB are obtained.

MAPPINGS

SNR

mutual information

CHANNEL

BICM

INFORMATION

extrinsic information transfer

bit-interleaved coded modulation

Binary labeling

Författare

A. Alvarado

University of Cambridge

Fredrik Brännström

Signaler och system, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

Erik Agrell

Signaler och system, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

IEEE Communications Letters

1089-7798 (ISSN)

Vol. 18 495-498 6784555

Ämneskategorier

Telekommunikation

DOI

10.1109/lcomm.2014.011314.132633