In this paper, we consider the quasi-maximum-likelihood (quasi-ML) detectors of the reverse link system that uses antenna arrays in asynchronous channels when the channel vector is time-invariant and time-varying. A channel vector estimation method based on eigendecomposition for time-invariant channels and its adaptive version suitable for the time-varying channels are also proposed. It is shown that the proposed quasi-ML detector can be regarded as a beamformer followed by a decorrelating filter and that the proposed system performs better than the conventional decorrelator scheme. It is also observed that the performance gain of the proposed scheme over the conventional decorrelator system increases as the numbers of active users and antenna arrays increase.
Bibliographical noteFunding Information:
Paper approved by R. Kohno, the Editor for Spread-Spectrum Theory and Applications of the IEEE Communications Society. Manuscript received March 29, 1998; revised March 30, 1999. This work was supported by a grant from Hallym Academy of Sciences, Hallym University, Korea. This paper was presented in part at the IEEE Global Telecommunications Conference, Phoenix, AZ, November 1997.
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering