The performance of a classical phase shift keying (PSK) detector may be degraded by parameter imprecision. This paper analyzes the performance variation of PSK schemes due to imprecision, and models the imprecise parameters as fuzzy numbers. Results illustrate the extent of the performance variation of the PSK schemes due to parameter imprecision in the analysis.

Shadow-feature-enhanced radar detection algorithms potentially allow the probability of target detection to be substantially increased when a target casts a radar shadow across a region of clutter beyond it. However, when the length of the radar shadow is not correctly known, much of the potential performance gain may be lost. We demonstrate a method for estimating the length of the radar shadow using a simple fuzzy system. We apply the shadow length estimation to the shadow-feature-enhanced maximum-likelihood constant false alarm rate (ML-CFAR) detector, showing that its performance can be greatly improved when the shadow length is not known a priori.

We investigate a dynamic packet routing approach to ATM switch design using a hypercube. An (n+1)-dimensional hypercube is used to implement an N/spl times/N switch, where N=2/sup n/. Cells arriving at input ports are routed towards their destinations in store-and-forward (SAF) manner. In addition to the SAF buffer, each input/output port has a dedicated buffer. A distributed deflection routing algorithm where the routing priority is based on the age of the cells is developed. An interesting feature of the routing algorithm is that the store-and-forward buffers and the input buffers behave as distributed shared-buffer which effectively smooth out uneven traffic. In addition, our routing algorithm does not suffer from the HOL blocking problem as in the conventional input-output buffered switch architecture. The processing power of each node in the hypercube scales up by a factor of Q(log N) as the network size N is increased. Hence, our approach is suitable for implementing large scale ATM switches. Performance of our design is studied via simulation and found to be better than the conventional input-output buffered nonblocking switch architecture.