Short-data-record design and analysis of adaptive receivers for smart-antenna-equipped DS/CDMA wireless communications systems

The objective of this work is the development of a theoretical framework and practical technology for adaptive receiver designs whenever high-dimensional adaptive linear processing with short data records is desired. Special emphasis is given to the problems of synchronization and demodulation as well as to the problem of estimation of the mobile user location. We develop analytic short-data-record tools for performance evaluation of adaptive receivers in realistic non-stationary environments where steady-state performance evaluation is primarily of theoretical value. Indeed, it is the finite sample support performance studies that are of real practical interest. Under finite data support adaptation the receiver becomes a random quantity. As a result, traditional steady-state-based performance measures such as the output signal-to-interference-plus-noise ratio (SINR), the induced BER, the achieved user capacity or the acquisition-error-rate of the receiver are stochastic in nature and can be studied only through their probability density functions. Our theoretical studies reveal the causes of performance deterioration under finite data-record-sizes and provide the foundation for the development of new receivers with improved short-data-record performance characteristics.