DocumentCode :
1469833
Title :
Performance of coherent DS-SS/QPSK for mobile communications in fast-fading multipath and high-frequency offset
Author :
Ko, Seok Jun ; Lee, Kyung Ha ; Choi, Hyung Jin
Author_Institution :
Sch. of Electr. & Comput. Eng., SungKyunKwan Univ., South Korea
Volume :
50
Issue :
1
fYear :
2001
fDate :
1/1/2001 12:00:00 AM
Firstpage :
250
Lastpage :
266
Abstract :
We derive a closed-form bit error rate (BER) solution for equal- and nonequal-strength L-path channels considering imperfect channel estimation. The channel model assumes independent paths with Rayleigh fading statistics in a single-cell downlink environment. By using a simple maximum likelihood (ML) estimator, the effects of the channel estimation error due to Doppler shift, residual carrier frequency offset, interference, and additive white Gaussian noise are analyzed. In addition, we present the tradeoff between the noise compression capability and phase tracking capability of the ML estimator with observation length as a parameter. The results indicate that even with channel estimation, the high carrier frequency offset makes an uncoded BER unacceptably high. Also, we present two kinds of modulation techniques such as EC-QPSK and NC-QPSK. Through analysis, we show the performance comparison between these modulation techniques. Finally, we verify the derived BER by using Monte Carlo computer simulation
Keywords :
AWGN; Doppler shift; Rayleigh channels; cellular radio; code division multiple access; error statistics; maximum likelihood estimation; multipath channels; multiuser channels; quadrature phase shift keying; radio links; radiofrequency interference; spread spectrum communication; CDMA; Doppler shift; EC-QPSK; Monte Carlo computer simulation; NC-QPSK; Rayleigh fading statistics; additive white Gaussian noise; bit error rate; channel estimation error; channel model; closed-form BER solution; coherent DS-SS/QPSK; fast-fading multipath; high carrier frequency offset; high-frequency offset; imperfect channel estimation; interference; maximum likelihood estimator; mobile communications; modulation; noise compression; observation length; performance; phase tracking; residual carrier frequency offset; single-cell downlink environment; uncoded BER; Bit error rate; Channel estimation; Doppler shift; Downlink; Frequency estimation; Maximum likelihood estimation; Mobile communication; Quadrature phase shift keying; Rayleigh channels; Statistics;
fLanguage :
English
Journal_Title :
Vehicular Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9545
Type :
jour
DOI :
10.1109/25.917936
Filename :
917936
Link To Document :
بازگشت