Throughput Analysis of Adaptive Modulated STS-based CDMA System Over Multipath Fading Channel

Abstract

The throughput enhancement of Space-Time Spreading (STS)-based Code Division Multiple Access (CDMA) system is investigated in this paper. Adaptive Modulation is utilized to improve the data throughput of the system in multipath Rayleigh fading channel. In this contribution, an analytical approach is proposed to compute a new expression for the Bit Error Rate (BER) performance and the output Signal-to-Interference-and-Noise Ratio (SINR) of the RAKE receiver-assisted STS-based CDMA system for QAM data, considering multipath and multiuser interferences. The other contribution of the paper is deriving a new closed form expression for computing the throughput enhancement and the BER performance of the adaptive modulated STS-based CDMA system over multipath fading channel. Simulation and analytical results demonstrate that using adaptive modulation method in this system improves the average throughput by keeping the BER performance at a target level. The novel expressions presented in this paper bring out the facility of evaluation of the proposed system with no need to more calculations and simulations.

CDMA-SFBC Downlink Performance

“…The power of the noise can be found by calculating the variance of B(2k) which can be expressed as in (11) after developing (9).…”

“…The performance of MC-CDMA combined with STBC over Rayleigh fading channels for one or two transmit antennas has been studied in [8]. In [9], the authors derived BER expressions for QAM data and studied the effects of adaptive modulation on the throughput of the RAKE receiver assisted space time spreading (STS) based CDMA system. Torabi et al in [10] derived closed form expressions for the BER of MIMO-OFDM-SFBC systems over Rayleigh fading channels.…”