Spatial transmit diversity schemes are now well integrated into third-generation cellular mobile communication system specifications. When DS-CDMA-based technology is deployed in typical macroand microcell environments, multipath diversity and spatial diversity may be exploited simultaneously by a 2D RAKE receiver. The work presented in this paper focuses on taking advantage of spatial transmit...

Abstract In direct sequence code division multiple access (DS-CDMA), frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion can be applied to exploit the channel frequency-selectivity and therefore much improved bit error rate (BER) performance than using the conventional rake combining. MMSE-FDE requires accurate frequency-domain channel estimation. In this pap...

This dissertation discusses two major topics, namely a diversity scheme and an adaptive data transmission, for realizing future broadband mobile multimedia communication systems. By using a diversity scheme and an adaptive data transmission, the system performance can be improved significantly. Since the system performances are degraded due to the inter-symbol interference (ISI) and multi-user ...

A novel linear precoding method that combines Multiuser Interference (MAI) cancellation, pre-RAKE filtering and Transmitter (Tx) antenna diversity is proposed for the downlink of the Code Division Multiple Access (CDMA) channel. It is demonstrated that this method has better performance than single user space-time pre-RAKE precoding with relatively low increase in complexity. In addition, sever...

This paper introduces a method that computes an estimation of the bit error rate (BER) based on the RAKE receiver soft output only. For this method no knowledge is needed about the channel characteristics nor the precise external conditions. Simulations show that the mean error of the estimation is below 2%, with only a small variance. Also an estimation of the BER for a different spreading fac...

In this paper, we present a simple interference cancellation technique for the downlink of wideband codedivision multiple-access (WCDMA) systems in multipath environment. With the same knowledge required by a RAKE receiver, the present method acts as an equalizer and cancels the interfering multipath signals from the received signal to retrieve the orthogonality property of the received signal....

In this letter, we propose the channel estimation technique in the uplink of a DS/CDMA system with M -ary orthogonal signaling over multipath fading channels. The channel estimation is carried out using the maximum correlator output of RAKE receiver. With the estimated channel parameters, the RAKE receiver can coherently combines the received multipath signals, resulting in a significant perfor...