Abstract
A performance analysis of orthogonal unified complex Hadamard transform (UCHT) spreading sequences in DS-CDMA downlinks is investigated in this paper. The coherent RAKE receiver is also adopted to reduce the effect of multipath fading. System performance is evaluated by means of signal-to-interference-plus-noise ratio (SINR) at the RAKE receiver. It is shown that the SINR of the system employing UCHT complex sequences is independent of the phase offsets between different paths, while the SINR of the system using Walsh-Hadamard (WH) sequences is related to the squared cosine of path phase offsets. As a result, the bit-error ratio (BER) performance of the DS-CDMA downlink system employing UCHT complex sequences is better than that of the system with WH sequences. Numerical simulations also demonstrate the benefits of the UCHT spreading sequences in the DS-CDMA downlinks with Rayleigh multipath fading.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
