RA-Type LDPC Codes를 이용한 HARQ의 부호율 조절 기법

Abstract

Strong rate-compatible codes are important to achieve high throughput of hybrid automatic repeat request (HARQ) systems in packet data transmission. This paper focuses on the construction of efficient rate-comparible low-density parity-check (RC LDPC) codes ovr a wide range of code rate. To construct RC LDPC codes, many rate-control schemes such as data puncturing (shortening), puncturing, extending, check node merging, and splitting have been proposed. We will explain these rate-control schemes and they are compared in terms of decoding convergence speed and decoding complexity. Also, we provide various rate-compatible repeat-accumulate-type LDPC (RC Ra-Type LDPC) codes obtained by using these rate-control schemes. RC Ra-Type LDPC codes such as rate-compatible punctured concatenated zigzag (RCPCZ) codes, rate-compatible irregular concatenated zigzag (RCICZZ) codes, check node merging rate-compatible block-type LDPC (CNM RC B-LDPC) codes, and splitting rate-compatible block-type LDPC (Splitting RC B-LDPC) codes give linear-time encoding, better performance, and higher throughput of type-Ⅱ HARQ than the conventional RC LDPC codes do. Therefore, thery can be a good candidate for the next-generation communication system which requires high system throughput.