The channel statistics are analyzed and evaluated for cooperative selection diversity with an amplify-and-forward (A&F) relay over Rayleigh fading channels. The average level crossing rate (LCR) and average fade duration (AFD) of the signal envelope for the dual-hop path and the cooperative selection diversity are evaluated. The moment generating function (MGF) of the signal-to-noise-ratio (SNR) and the amount of fading (AOF) are derived, and the symbol error rate (SER) of different modulation schemes is evaluated. Numerical results are presented for performance examinations.

The analytical average level crossing (LCR) of the envelope process for multihop fading channels with the amplify-and-forward (AF) relay is derived by using the counting functional, where the fading factors of different hops are assumed to be independent. The evaluation of the analytical LCR involves integrals that are difficult to compute. To evaluate the LCR, the lower bound and the upper bound on the LCR are derived. The cases of Rayleigh and Rician fading channels are considered, where the lower bound and the upper bound are assessed. Numerical results are presented for different fading parameters.

The average level crossing rate and the average fade duration will be evaluated for multi-branch selection diversity over dependent Weibull fading channels. First the general dependent Weibull fading model is established. Then, the average level crossing rate and the average fade duration are analyzed. Numerical results of the average level crossing rate and corresponding average fade duration are presented for the selection diversity on the dependent Weibull fading channel and compared to the ones on independent Weibull fading channels.

To increase the data rate for future wireless systems, a novel scheme using multiple transmit antennas for space digital modulation is proposed. In the scheme of space modulation, more than two antennas are employed to transmit and signal the information bits. The novel space modulation scheme is termed space shift keying (SSK). Numerical results are presented to examine the reception performance.

Optimum multisensor data fusion is addressed for image change detection based on the optimum likelihood ratio test for the statistical dependence of the luminance signals in additive Gaussian noise. It is demonstrated that the information to be transmitted from the sensors to the fusion center is the maximum likelihood estimates of the correlation coefficients between pairs of consecutive image frames. Experimental results illustrate that the detection error decreases as the number of sensors and/or frames increases.>

Two diversity schemes with distributed decisions are analyzed for BPSK direct-sequence code division multiple access (DS-CDMA) in a shadowed Rician fading land-mobile satellite channel. The Chernoff upper bounds on the probabilities of bit error are derived for the performance evaluation. Numerical results are presented for the performance comparisons between the distributed decision, the selection and maximal ratio combining for DS-CDMA in which the phase of the desired signal is Gaussian distributed.>

The problem of distributed estimation of a weak nonrandom location parameter theta in additive stationary dependent noise is addressed. Multisensor configurations with and without a coordinator are considered. Dependence in the sensor observations is described by m-dependent, phi -mixing, and p-mixing models. Two cases of interest are addressed: one in which sensor observations are dependent across time but independent across sensors and one in which sensor observations are dependent across both time and sensors. Numerical results on the performance evaluation of the various estimation schemes derived are presented and the relative performances of the various schemes are compared.>

Minimax robust data fusion schemes for multisensor detection systems with discrete-time observations characterized by statistical uncertainty are developed and analyzed. Block, sequential, and serial fusion rules are considered. The performance measures used, and made robust with respect to the uncertainties, include the error probabilities of the hypothesis testing problem in the block fusion case and the error probabilities and expected numbers of samples or sensors in the sequential and serial fusion cases. For different sensor observation statistics, the minimax robust fusion rules are derived for two asymptotic cases of interest: when the number of sensors is large and when the number of times the fusion center collects the local (sensor) decisions is large. Moreover, for the case of identical sensor observation statistics and a large number of sensors, it is shown that there is no loss in optimality, if local tests using likelihood ratios and equal thresholds are used in the sequential fusion rule. In all situations, the robust decision rules at the sensors and the fusion center are shown to make use of likelihood ratios and thresholds that depend on the least-favorable probability distributions of the uncertainty class describing the statistics of sensor observations.>