Blind user detection in doubly-dispersive DS/CDMA channels

TL;DR

This paper introduces a blind detection method for identifying new users in DS/CDMA systems operating over doubly-dispersive fading channels, requiring only the user's spreading code and achieving reliable detection under interference and mobility.

Contribution

A novel blind detection strategy that does not need prior channel information, maintaining CFAR and effective detection in challenging conditions.

Findings

Achieves bounded CFAR under design assumptions.

Performs well with strong cochannel interference.

Effective in high mobility scenarios.

Abstract

In this work, we consider the problem of detecting the presence of a new user in a direct-sequence/code-division-multiple-access (DS/CDMA) system with a doubly-dispersive fading channel, and we propose a novel blind detection strategy which only requires knowledge of the spreading code of the user to be detected, but no prior information as to the time-varying channel impulse response and the structure of the multiaccess interference. The proposed detector has a bounded constant false alarm rate (CFAR) under the design assumptions, while providing satisfactory detection performance even in the presence of strong cochannel interference and high user mobility.