In this paper, we propose a robust adaptive minimum mean square error (MMSE) Rake receiver for asynchronous DS-CDMA systems. The receiver uses the modified MMSE criterion that incorporates the differential detection and the amplitude compensation for interference cancellation in a time-varying multipath fading channel. We investigate that the proposed Rake receiver can achieve the higher output...

Error rates of orthogonal frequency division multiplexing (OFDM) signals are considered for system using multichannel reception with maximum ratio combining (MRC) receivers in Nakagami-m fading generated by sum of sinusoidal method using Rayleigh and Ricean channel. The paper also discusses the effect of frequency offsets, nakagami-m parameter m on OFDM systems. Also effect of frequency offset ...

In this paper, we analyze the performance of a signature quantization scheme for reverse-link Direct Sequence (DS)Code Division Multiple Access (CDMA). Assuming perfect estimates of channel and interference covariance, the receiver selects the signature that maximizes signal-to-interference plus noise ratio (SINR) for a desired user from a signature codebook. The codebook index corresponding to...

The control and reduction of multiuser interference is a fundamental problem in wireless communications. In order to increase the spectral efficiency and to provide individual quality-of-service (QoS), it is required to jointly optimize the power allocation together with possible receive and transmit strategies. This often leads to complex and difficult-to-handle problem formulations. There are...

In mobile networks handover is initiated when there is change in network Quality of Service (QoS) parameters such as signal strength, signal to interference noise ratio (SINR), bit error rate (BER) etc. Handover considering signal strength is a basic scheme in mobile networks. Considering only signal strength is not ideal for WiMAX networks, which has stringent QoS requirements. Signal strength...

An upper bound is derived on the capacity of a cognitive radio (CR) system by considering the effects of path loss and log-normal shadowing simultaneously for a single-cell network. Assuming that the cognitive radio is informed only of the shadow fading between the secondary (cognitive) transmitter and primary receiver, the capacity is achieved via the water-filling power allocation strategy un...

The interference reduction capability of antenna arrays and the power control algorithms have been considered separately as means to increase the capacity in wireless communication networks. The minimum variance distortionless response beamformer maximizes the signal-to-interference-and-noise ratio (SINR) when it is employed in the receiver of a wireless link. In a system with omnidirectional a...

Genetic Algorithm (GA) assisted beamforming techniques are proposed as an alternative to conventional beamforming algorithms. The design of the corresponding GAs is highlighted and the achievable performance is characterised in terms of the Signal-to-Interference Ratio (SIR) and the Signal-to-Interference plus Noise Ratio (SINR). It is demonstrated that an attractive SINR versus complexity trad...

The random access systems, with retransmission diversity (RD) employment, over large random spreading code division multiple access (CDMA) channel subject to fading is investigated, under the assumption of infinite number of users and infinite spreading gain with their ratio converging to a constant. The low bound of the signal to interference and noise ratio (SINR) is shown to converge almost ...

In this paper, we propose a novel on-demand energy-aware routing protocol, UBPCR [utility-based power control routing], which reduces the trade-offs that arise in the other energy-aware route selection mechanisms that have recently been proposed for mobile ad hoc networks. Our approach is based on an economic framework that represents the degree of link’s satisfaction (utility). With UBPCR, the...