Title :
Adaptive Resource Allocation for Spectral Efficiency Maximization in Uplink WCDMA
Author :
Zarringhalam, Farhad ; Shikh-Bahaei, Mohammad R. ; Charbit, Gilles
Author_Institution :
King´´s Coll. London
Abstract :
In this contribution we examine the joint optimization of the outer-loop power control (OLPC) and spreading factor in order to improve the spectral efficiency in the uplink of wideband code-division multiple-access (WCDMA) systems, in the presence of additive white Gaussian noise (AWGN) and multiple access interference (MAI), and while maintaining an average transmit power constraint. The variable spreading factors (VSF) and the target signal-to-noise ratio (SNR) -set by the OLPC - are adapted according to the interference-to-noise ratio (INR) and the target instantaneous bit error rate (BER). We use the standardized orthogonal VSF (OVSF) codes used for the uplink dedicated physical data channel (UL-DPDCH) and evaluate the performance over Nakagami flat fading channels. It is shown that the proposed scheme improves the spectral efficiency compared to systems that use constant spreading factor and OLPC, for a wide range of practical SNRs and signal-to-interference ratios (SIRs)
Keywords :
AWGN channels; Nakagami channels; code division multiple access; error statistics; power control; radio links; radiofrequency interference; telecommunication control; AWGN; BER; MAI; Nakagami flat fading channels; SIR; SNR; adaptive resource allocation; additive white Gaussian noise; bit error rate; multiple access interference; outer-loop power control; signal-to-interference ratios; spectral efficiency maximization; spreading factor; target signal-to-noise ratio; transmit power constraint; uplink WCDMA; uplink dedicated physical data channel; variable spreading factors; wideband code-division multiple-access; AWGN; Additive white noise; Bit error rate; Constraint optimization; Multiaccess communication; Multiple access interference; Power control; Resource management; Signal to noise ratio; Wideband; outer-loop power control (OLPC); variable spreading factor (VSF); wideband code-division multiple-access (WCDMA);
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 2006 IEEE 17th International Symposium on
Conference_Location :
Helsinki
Print_ISBN :
1-4244-0329-4
Electronic_ISBN :
1-4244-0330-8
DOI :
10.1109/PIMRC.2006.254217