Title :
On the differences between uplink and downlink transmission in code-spread CDMA systems
Author :
Persson, Anders ; Lassing, Johan ; Ottosson, Tony ; StröM, Erik
Author_Institution :
Dept. of Signals & Syst., Chalmers Univ. of Technol., Goteborg, Sweden
Abstract :
The bit error rate (BER) of a code spread CDMA system, using low rate convolutional codes for spreading, is analyzed. The system is assumed to operate over a Rayleigh flat fading channel, and white Gaussian noise is added at the receiver front end. Based on a Gaussian approximation, expressions for the pdf of the signal-to-noise ratios are derived for both uplink and downlink transmission. Computer simulations of the system BER, as well as analytical results based on a union bound, are presented. The analytical results are in close agreement with the computer simulations
Keywords :
AWGN channels; Rayleigh channels; cellular radio; channel coding; code division multiple access; convolutional codes; error statistics; probability; spread spectrum communication; BER; CDMA; Gaussian approximation; Rayleigh flat fading channel; bit error rate; cellular radio; code spread system; convolutional codes; downlink transmission; pdf; receiver front end; signal-to-noise ratios; spreading codes; uplink transmission; white Gaussian noise; Bit error rate; Convolutional codes; Detectors; Downlink; Fading; Gaussian noise; Maximum likelihood detection; Multiaccess communication; Random variables; Transmitters;
Conference_Titel :
Vehicular Technology Conference, 2001. VTC 2001 Spring. IEEE VTS 53rd
Conference_Location :
Rhodes
Print_ISBN :
0-7803-6728-6
DOI :
10.1109/VETECS.2001.944035
