New results on low complexity detectors for over-saturated CDMA systems

TitleNew results on low complexity detectors for over-saturated CDMA systems
Publication TypeConference Paper
Year of Publication2001
AuthorsDjonin, D. V., and V. K. Bhargava
Conference NameGlobal Telecommunications Conference, 2001. GLOBECOM '01. IEEE
Pagination846 -850 vol.2
Keywordsbinary sequences, bit-error rate, channel capacity, code division multiple access, error statistics, Gaussian approximation, group orthogonal sequence allocation, interference cancellation, interference suppression, low-complexity multiuser detection, mobile radio, multistage iterative alternative detection, multiuser channels, optimal joint multiuser detection, optimisation, oversaturated synchronous CDMA, performance analysis, signal detection, space altering generalized expectation maximization algorithm, Welch bound

This paper analyzes two different low-complexity multiuser detection schemes for the oversaturated synchronous CDMA systems, ie, systems which can accommodate more users than the processing gain of the system. The first scheme is multistage iterative alternative detection of the users of the two groups combined with interference cancellation. The bit-error rate performance analysis of this scheme using Gaussian approximation is also derived and it is shown that this scheme is the realization of the space altering generalized expectation maximization algorithm known in signal processing literature. As an improvement for the shortcomings of the first scheme in near-far situations, a group orthogonal sequence allocation scheme is introduced. It is demonstrated that it can lead to efficient optimal multiuser detection. It is also shown that if all groups of sequences attain the Welch bound for the sum of squared sequence correlation coefficients then the optimal joint multiuser detection maximizes the sum capacity of the channel


a place of mind, The University of British Columbia

Electrical and Computer Engineering
2332 Main Mall
Vancouver, BC Canada V6T 1Z4
Tel +1.604.822.2872
Fax +1.604.822.5949

Emergency Procedures | Accessibility | Contact UBC | © Copyright 2021 The University of British Columbia