Blind Adaptive MIMO Receivers for Space-Time Block-Coded DS-CDMA Systems in Multipath Channels Using the Constant Modulus Criterion

TL;DR

This paper introduces blind adaptive MIMO receivers for DS-CDMA systems with space-time block coding, utilizing a constant modulus criterion and RLS algorithms for improved performance in multipath channels.

Contribution

It presents a novel CCM-based design and RLS algorithms for blind adaptive MIMO receivers and a subspace-based channel estimation method for DS-CDMA systems with STBC.

Findings

Enhanced receiver performance in multipath channels

Effective blind channel estimation with subspace approach

Outperforms existing methods in simulations

Abstract

We propose blind adaptive multi-input multi-output (MIMO) linear receivers for DS-CDMA systems using multiple transmit antennas and space-time block codes (STBC) in multipath channels. A space-time code-constrained constant modulus (CCM) design criterion based on constrained optimization techniques is considered and recursive least squares (RLS) adaptive algorithms are developed for estimating the parameters of the linear receivers. A blind space-time channel estimation method for MIMO DS-CDMA systems with STBC based on a subspace approach is also proposed along with an efficient RLS algorithm. Simulations for a downlink scenario assess the proposed algorithms in several situations against existing methods.