Performance Analysis of a Six-Port Receiver in a WCDMA Communication System including a Multipath Fading Channel

Third generation communication systems require receivers with wide bandwidth of operation to support high transmission rates and are also reconfigurable to support various communication standards with different frequency bands. An ideal software defined radio (SDR) will be the absolute answer to this requirement but it is not achievable with the current level of technology. This paper proposes the use of a six-port receiver (SPR) front-end (FE) in a WCDMA communication system. A WCDMA end-to-end physical layer MATLAB demo which includes a multipath channel distortion block is used to determine the viability of the six-port based receiver. The WCDMA signal after passing through a multipath channel is received using a constructed SPR FE. The baseband signal is then calibrated and corrected in MATLAB. The six-port receiver performance is measured in terms of bit error rate (BER). The signal-to-noise ratio (SNR) of the transmitted data is varied and the BER profile of the communication system is plotted. The effect of the multipath fading on the receiver performance and the accuracy of the calibration algorithm are obtained by comparing two different measured BER curves for different calibration techniques to the simulated BER curve of an ideal receiver. 1. Introduction Third generation (3G) mobile communication systems introduced in recent years are a huge step in increasing wireless transmission capacity, fidelity, and efficiency. The increasing number of cellular standards together with the variety of frequency bands these standards use in different regions of the world demands a high degree of reconfigurability. The idea of reconfigurability applies not only to the baseband processing but also to the RF front-end. As a result, reconfiguration has become the key issue in the design of wireless terminals [1]. The implication is that the receiver front-end (FE) is required to have a wide bandwidth to support a high data transmission rate and it should also be multimode and multistandard to support fast and constantly evolving modern communication systems. This enables forward and backward compatibility. Power requirement, fidelity, size, and cost are also paramount properties to consider in a receiver front-end design. An example of 3G mobiles communication standard is the WCDMA communication systems, which compared to the second generation systems have a larger system capacity and greater coverage area to provide higher transmission rate and more services to consumers. An ideal software defined radio (SDR) will be the optimum solution to satisfy the