Iterative decoding and channel estimation of DS/CDMA over slow Rayleigh fading channels
ABSTRACT We investigate the application of joint decoding and channel
estimation for DS/CDMA transmission over slow Rayleigh fading channels.
Some known symbols are inserted in the encoded data stream to enhance
the channel estimation process. An iterative algorithm that uses the
decoding information, in addition to the information contained in the
known symbols, to improve the channel parameters estimate is proposed. A
is shown that the optimum scheme has a complexity which grows
exponentially with the channel estimation filter length. Hence, we
propose some alternative sub-optimum schemes with polynomial complexity.
The different techniques that provide a tradeoff between simplicity of
implementation and BER performance are compared