Title :
On the performance of a CDMA system with user signatures based on packet wavelets in multipath channels
Author :
Ionescu, D. Mihai ; Wickert, Mark A.
Author_Institution :
Dept. of Electr. & Comput. Eng., Colorado Univ., CO, USA
Abstract :
A class of optimum full response signaling envelopes for a single user system are identified; such signaling waveforms can isolate the multiple paths and facilitate the estimation of path parameters with a matched filter scheme. The effect of both pure multipath and combined multipath/multiuser interference (asynchronous) on the estimation of parameters for an isolated path is described; upper margins for the signal to noise ratio degradation are derived in two settings, namely for packet wavelet and PN/Gold code signatures, respectively. Numerical results are shown for the upper margins. The performance with shift orthogonal envelopes shows an overwhelming improvement over Gold codes, especially when the signature regularity increases. Bandwidth wise, it turns out that packet wavelet signatures are twice as compact as PN codes for a given delay resolution. The major disadvantage of shift-orthogonal waveforms is a nonconstant envelope
Keywords :
code division multiple access; delays; filtering theory; matched filters; multipath channels; packet radio networks; parameter estimation; pseudonoise codes; radiofrequency interference; spread spectrum communication; telecommunication signalling; wavelet transforms; CDMA system performance; Gold code; PN codes; bandwidth; delay resolution; matched filter; multipath channels; multipath interference; multiuser interference; nonconstant envelope; optimum full response signaling envelopes; packet wavelet signatures; path parameter estimation; shift orthogonal envelopes; shift orthogonal waveforms; signal to noise ratio degradation; signaling waveforms; signature regularity; single user system; upper margins; user signatures; Bandwidth; Degradation; Gold; Interference; Matched filters; Multiaccess communication; Parameter estimation; Signal processing; Signal to noise ratio; Wavelet packets;
Conference_Titel :
Vehicular Technology Conference, 1997, IEEE 47th
Conference_Location :
Phoenix, AZ
Print_ISBN :
0-7803-3659-3
DOI :
10.1109/VETEC.1997.596387