Title :
Bandwidth constrained signature waveforms for maximizing the network capacity of synchronous CDMA systems
Author :
Nguyen, Ha H. ; Shwedyk, E.
Author_Institution :
Dept. of Electr. & Comput. Eng., Manitoba Univ., Winnipeg, Man., Canada
Abstract :
Synchronous CDMA systems where each receiver is a minimum mean-squared-error (MMSE) receiver and each user has the same received power, signaling rate and required signal-to-interference ratio (SIR) are considered. Given a SIR requirement and under different bandwidth constraints and a fixed-dimension signature space, the optimal signature waveforms to maximize the network capacity, i.e., the maximum number of users that can be accommodated in the systems are determined. Both fractional out-of-band energy (FOBE) and root-mean-square (RMS) bandwidth constraints are examined. Comparison to various suboptimal signature waveforms, including the commonly used rectangular pulses, is also made to quantify the gain achieved by the optimal signature waveforms
Keywords :
channel capacity; code division multiple access; least mean squares methods; multiuser channels; optimisation; radio networks; radio receivers; radiofrequency interference; spread spectrum communication; waveform analysis; MMSE receiver; RMS bandwidth constraints; SIR; bandwidth constrained signature waveforms; fixed-dimension signature space; fractional out-of-band energy; minimum mean-squared-error receiver; network capacity; network capacity maximisation; optimal signature waveforms; received power; receiver; rectangular pulses; root-mean-square bandwidth constraints; signal-to-interference ratio; signaling rate; single-user matched filter; suboptimal signature waveforms; synchronous CDMA systems; Additive white noise; Bandwidth; Code division multiplexing; Interference constraints; Interference elimination; Multiaccess communication; Multiple access interference; Multiuser detection;
Conference_Titel :
Spread Spectrum Techniques and Applications, 2000 IEEE Sixth International Symposium on
Conference_Location :
Parsippany, NJ
Print_ISBN :
0-7803-6560-7
DOI :
10.1109/ISSSTA.2000.876468