An iterative adaptive receiver design using the multi-layer RLS algorithm with applications to layered space time coded systems

Abstract

Layered space-time (LST) architectures can support efficient signal processing in multiple-input multiple-output (MIMO) systems. Current applications to LST systems are based on pilot-aid transmissions, with the problem of reducing spectral efficiency. In this paper, the new adaptive algorithm called multilayer recursive least square (RLS) is applied to an iterative receiver structure in LST systems. A multi-layer RLS algorithm is an efficient method to provide accurate interference cancellation and fast convergence. This multi-layer RLS adaptive iterative receiver considers joint detection/decoding and channel estimation to avoid the periodic insertion of pilot-tones and hence improves spectral efficiency. The proposed iterative adaptive receiver is compared with a lower bound non-adaptive MMSE receiver where the channel state information (CSI) is assumed to be perfectly known a priori at the receiver. The proposed receiver structure is suitable for MIMO systems in slow time variant channels. Simulation results are supplied to demonstrate the excellent performance of the proposed multi-layer RLS adaptive receiver over a conventional linear RLS receiver.