Title :
Soft decisions for DQPSK demodulation for the Viterbi decoding of the convolutional codes
Author :
Hewavithana, Thushara C. ; Brookes, Mike
Author_Institution :
Dept. of Electr. & Electron. Eng., Imperial Coll., London, UK
Abstract :
The conventional soft decision algorithm for DQPSK uses only the differential angle between consecutive DQPSK symbols. However it is possible to improve the accuracy of the soft decision bits by taking the amplitude information of the two DQPSK symbols into account. This paper introduces novel soft decision algorithms based on this approach which give a performance improvement compared to the conventional methods equivalent to an SNR gain of up to 5 dB.
Keywords :
Viterbi decoding; cellular radio; channel coding; convolutional codes; differential phase shift keying; digital radio; quadrature phase shift keying; DQPSK demodulation; DQPSK symbols; Viterbi decoding; amplitude information; convolutional codes; digital cellular systems; soft decision algorithms; Amplitude estimation; Bit error rate; Convolutional codes; Demodulation; Digital modulation; Educational institutions; Iterative algorithms; Iterative decoding; Performance gain; Viterbi algorithm;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03). 2003 IEEE International Conference on
Print_ISBN :
0-7803-7663-3
DOI :
10.1109/ICASSP.2003.1202530
