Title :
Symbol mapping diversity in iterative decoding/demodulation of ARQ systems
Author :
Samra, Harvind ; Ding, Zhi
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Davis, CA, USA
Abstract :
This paper presents a simple, yet effective method of enhancing the inherent diversity among packet retransmissions in digital communication systems that employ high-order modulations such as M-PSK and M-QAM through frequency-selective channels. Diversity is enhanced by uniquely redefining the bit-to-symbol mapping for each retransmission. Finding the optimal mappings leads to iterative solutions of the quadratic assignment problem. More importantly, jointly equalizing transmission with different mappings only requires a marginal increase in complexity, while providing substantial gains in bit error rates (BER) and frame error rates (FER).
Keywords :
automatic repeat request; demodulation; digital communication; diversity reception; error statistics; iterative decoding; phase shift keying; quadrature amplitude modulation; ARQ systems; BER; FER; bit error rates; bit-to-symbol mapping; digital communication systems; frame error rates; frequency-selective channels; iterative decoding; iterative demodulation; jointly equalizing transmission; packet retransmissions; symbol mapping diversity; Automatic repeat request; Bit error rate; Demodulation; Diversity reception; Error correction; Frequency diversity; Intersymbol interference; Iterative decoding; Maximum likelihood decoding; Transmitters;
Conference_Titel :
Communications, 2003. ICC '03. IEEE International Conference on
Print_ISBN :
0-7803-7802-4
DOI :
10.1109/ICC.2003.1204121
