Performance Of Wideband Code Division Multiple Access System Research Articles

Performance Analysis of WCDMA using Different Spreading Codes

Recently, Wideband Code Division Multiple Access (WCDMA) technology has emerged as the most widely adopted third generation (3G) air interface. Conventionally, the Pseudo random Noise (PN) sequence and gold code sequence are used as spreading codes in WCDMA. However enhanced performance using these sequences is achieved by increasing the length of the sequence. In this paper, Bit Error Rate (BER) performance of WCDMA is determined and analyzed by considering various spreading codes of affordable spreading factor in the presence of Rayleigh channel with AWGN. The performance of WCDMA system using Walsh Code is also compared with other spreading sequences such as PN and gold sequence for various Spreading Factors (SFs). However, simulation results show that the BER of WCDMA can be improved drastically by using Walsh code.

Performance Analysis of WCDMA System for LEO Satellite Channel

In a Low Earth Orbit (LEO) satellite mobile multimedia system, the multiple access scheme should be capable of supporting the necessary features that would facilitate the provision of multimedia services. Wideband Code Division Multiple Access (WCDMA) is an attractive multiple access scheme for mobile multimedia communications based on LEO satellites. In this paper, the performance of WCDMA system over LEO satellite channel is evaluated. The performance is measured in terms of the bit error probability. A mathematical derivation of the bit error probability is presented. A rake receiver with maximal ratio combining is considered in the analysis. The effect of the number of users and the processinggain on the performance of the WCDMA system is investigated.

BER Performance of Space-Time Coded MMSE DFE for Wideband Code Division Multiple Access (WCDMA)

In recent times, there has been growing interests in integration of voice, data and video traffic in wireless communication networks. With these growing interests, WCDMA has immerged as an attractive access technique. The performance of WCDMA system is deteriorated in presence of multipath fading environment. The paper presents space-time coded minimum mean square error (MMSE) Decision Feedback Equalizer (DFE) for wideband code division multiple access (WCDMA) in a frequency selective channel. The filter coefficients in MMSE DFE are optimized to suppress noise, intersymbol interference (ISI), and multiple access interference (MAI) with reasonable system complexity. For the above structure, we have presented the estimation of BER for a MMSE DFE using computer simulation experiments. The simulation includes the effects of additive white Gaussian noise, multipath fading and multiple access interference (MAI). Furthermore, the performance is compared with standard linear equalizer (LE) and RAKE receiver. Numerical and simulation results show that the MMSE DFE exhibits significant performance improvement over the standard linear equalizer (LE) and RAKE receiver.