Title :
Adaptive linear-quadratic (LQ) receivers for time-varying, frequency-selective code-division-multiple-access channels
Author :
Ni, Jianjun ; Barton, Richard J.
Author_Institution :
Dept. of Electr. & Comput. Eng., Iowa State Univ., Ames, IA, USA
Abstract :
We study the design and analysis of adaptive linear-quadratic (LQ) receivers for time-varying, frequency-selective CDMA environments. We propose a simple, intuitively appealing cost function that can be maximized to find linear-quadratic (LQ) detectors that are optimal in a certain sense. We discuss the motivation and derivation of the proposed LQ cost function and derive an adaptive algorithm for LQ detectors that can be viewed as a generalization of the minimum-output-energy algorithm for the MMSE linear detector. We also discuss an approach to adaptive signal design for time-varying channels based on the proposed LQ cost function. Finally, we present the results of a simulation study that clearly demonstrates the potential performance advantage of the proposed LQ receivers vis-g-vis MMSE linear receivers.
Keywords :
adaptive signal detection; code division multiple access; least mean squares methods; multiuser channels; radio receivers; signal synthesis; spread spectrum communication; time-varying channels; DS-CDMA; LQ cost function; MMSE linear detector; MMSE linear receivers; adaptive algorithm; adaptive linear-quadratic receivers; adaptive signal design; code-division-multiple-access; frequency-selective CDMA channels; minimum-output-energy algorithm; performance; simulation study; time-varying channels; Additive noise; Bayesian methods; Cost function; Detectors; Frequency; Intersymbol interference; Multiaccess communication; Multiple access interference; Noise robustness; Uncertainty;
Conference_Titel :
Signals, Systems, and Computers, 1999. Conference Record of the Thirty-Third Asilomar Conference on
Conference_Location :
Pacific Grove, CA, USA
Print_ISBN :
0-7803-5700-0
DOI :
10.1109/ACSSC.1999.831849