A Novel Code-Aided Carrier Recovery Algorithm for Coded Systems

Author

Xin Man ; Zhipeng Xi ; Kai Gao ; Eryang Zhang

Author_Institution

Sch. of Electron. Sci. & Eng., Nat. Univ. of Defense Technol., Changsha, China

Volume

17

Issue

2

fYear

2013

fDate

Feb-13

Firstpage

405

Lastpage

408

Abstract

We present a novel code-aided carrier recovery method for low-density parity-check (LDPC) coded systems, which comprises two supporting algorithms: 1) a coarse synchronization by maximizing a cost function, the mean absolute value of the soft outputs of the LDPC decoder, followed by a simple interpolation operation to improve the estimation accuracy and 2) a fine synchronization based on the soft decisions produced by the LDPC decoder. With moderate computational complexity, this proposed algorithm is designed to synchronize signals with large carrier frequency offset and phase offset at low signal-to-noise ratio (SNR). When applied to the case of an 8-PSK system with (1944,972) LDPC code, the performance loss compared to the case of ideal synchronization is negligible.

Keywords

computational complexity; estimation theory; interpolation; parity check codes; phase shift keying; synchronisation; 8-PSK system; LDPC decoder; SNR; coarse synchronization; code-aided carrier recovery algorithm; computational complexity; cost function maximization; interpolation operation; large carrier frequency offset; low-density parity-check decoding system; mean absolute value; phase offset; signal-to-noise ratio; soft decision; Decoding; Estimation; Frequency estimation; Frequency synchronization; Parity check codes; Signal to noise ratio; Synchronization; Code-aided; LDPC; carrier recovery; large carrier frequency offset; low SNR;

fLanguage

English

Journal_Title

Communications Letters, IEEE

Publisher

ieee

ISSN

1089-7798

Type

jour

DOI

10.1109/LCOMM.2012.121912.122278

Filename

6400347