The issue of bandwidth scaling has always caused some confusion for channels subject t.o additive white Gaussian noise plus multipath fading. On the one hand, there is an old result (see, for example, section 8.6 of [I]) saying that the capacity of the channel (under 2 power constraint but no bandwidth constraint) is the same as the infinite bandwidth capacity of the non-fading additive noise c...

Orthogonal Frequency Division Multiplexing (OFDM) has become a very popular method for high data rate wireless communications because of its advantages over single carrier modulation schemes on multi-path, frequency selective fading channels. However, inter-carrier interference due to Doppler frequency shifts, and multipath fading severely degrades the performance of OFDM systems. Estimation of...

| Space-time coding and interference cancellation based on orthogonal projection are powerful techniques to improve the communication quality and capacity in downlink CDMA systems. Space-time encoder output stream is transmitted through fading channel using multiple transmitter antennas, increasing communication reliability against multipath fading. On the other hand, orthogonal projection-base...

In this paper we propose a feedforward method to estimate the multipath delays in a fading channel at subchip resolution and able to deal with multipath merging phenomenon. The multipaths are searched in the envelope of the correlation function between the received signal and a reference signal. The correlation function is obtained in the oversampled domain and the resolution of the delay estim...

In this paper, the uplink multiuser code division multiple access (CDMA) communication system model is described in the form of space-time domain through antenna array and multipath fading expression. Novel suitable neural network technique is proposed as an effective signal processing method for the receiver of such an uplink multiuser CDMA system. By the appropriate choice of the channel stat...

The energy detection of Continuous Phase Frequency Shift Keying (CP-FSK) signals is the optimum noncoherent detection technique yielding a minimum bit error rate (BER) on the additive white Gaussian noise (AWGN) channel. This scheme is usually used when carrier phase estimation is difficult. When a CP-FSK signal is passed through a frequency selective multipath fading channel, inter-symbol inte...

Multipath fading is one of the major practical concerns in wireless communications. Multipath problem always exists in mobile environment, especially for mobile unit which is often embedded in its surroundings. A time-variant tapped line delay model has been used for multipath fading in a wide-band spread spectrum mobile system. In this paper, we proposed to use the detection and estimation tec...

The character of multipath-induced propagational fading is reviewed, along with the interpretations underlying use of the Ray-leigh fading model to describe the process statistics. The relationship between this model and contemporary laboratory fading simulators is also outlined. The effects of the fading upon data communications are described, along with the techniques of modulation, diversity...

The reverse-link performance of synchronous DS-CDMA is investigated in Rician multipath fading environments. The numerical results show that the performance benefits of synchronous transmission depend on the specular path’s power as well as on the multipath intensity decay factor of the channel. The achievable bit-error-rate reduction may become as high as an order of magnitude in comparison to...