Title :
Analysis of coded noncoherent transmission in DS-CDMA mobile satellite communications
Author :
Corazza, Giovanni E. ; Gaudenzi, Riccardo De
Author_Institution :
Dipt. di Ingegneria Elettronica, Rome Univ., Italy
fDate :
11/1/1998 12:00:00 AM
Abstract :
The paper analyzes possible transmission schemes for satellite personal communication systems adopting low/medium-Earth orbit (LEO/MEO) constellations and direct-sequence code division multiple access (DS-CDMA) in the presence of fading and shadowing, the statistics of which are functions of the satellite elevation angle. In particular, the performance of M-ary Walsh-Hadamard orthogonal (MWHO) convolutionally coded DS-CDMA over a Rice-log-normal fading channel is analyzed in depth, and compared to the simpler coded differential BPSK (DBPSK) scheme. Optimization of the performance/complexity tradeoff in the metric computation for soft inputs to the Viterbi (1979) decoder is addressed. Upper bounds on the error probability without or with satellite diversity and equal gain combining are evaluated considering different coding rates. The effect of correlated fading is also taken into account via simulation. Among the various results, it is shown that the optimal coding rate is a function of the satellite elevation angle and of the diversity order, that the loss for using DBPSK instead of MWHO is in the range 1-1.4 dB, and that interleaving depth is a critical parameter
Keywords :
Hadamard codes; Rician channels; Viterbi decoding; code division multiple access; convolutional codes; correlation methods; differential phase shift keying; diversity reception; error statistics; log normal distribution; mobile satellite communication; optimisation; personal communication networks; signal detection; spread spectrum communication; DS-CDMA mobile satellite communications; LEO/MEO constellations; M-ary Walsh-Hadamard orthogonal convolutional code; MWHO; Rice-log-normal fading channel; Viterbi decoder; coded differential BPSK; coded noncoherent transmission; coding rates; correlated fading; direct-sequence code division multiple access; diversity order; equal gain combining; error probability; interleaving depth; low/medium-Earth orbit; optimal coding rate; performance/complexity tradeoff; satellite diversity; satellite elevation angle; satellite personal communication systems; shadowing; simulation; soft inputs; soft noncoherent detection; statistics; upper bounds; Artificial satellites; Binary phase shift keying; Convolutional codes; Diversity reception; Fading; Low earth orbit satellites; Multiaccess communication; Performance analysis; Shadow mapping; Statistical analysis;
Journal_Title :
Communications, IEEE Transactions on
