Joint precoder and decoder optimization is considered for uplink multiuser multiple-input multiple-output (MU-MIMO) systems with limited channel state information (CSI) at both the transmitters and receivers. Instead of counting on complex iterative-based algorithms, an efficient and noniterative QR-based linear transceiver pair design is employed. In addition, an equal power distribution (EPD) scheme is applied to adjust transmit power allocation of each mobile station (MS) between its symbols under the total transmit-power constraint. Simulations are conducted to provide a comparative evaluation of the proposed QR-EPD algorithm with other transceiver designs on the sum mean-squared error (SMSE) and the averaged bit-error-rate (BER) performance.

Owing to the emerging demand on multimedia applications, next-generation wireless communication systems are expected to improve substantially both reliability and spectral efficiency. A key development in this regard is the use of multiple antenna arrays at both the base station (BS) and mobile station (MS) [

The rest of the paper is organized as follows. Section

Symbols for matrices (vectors) are denoted by boldface upper (lower) case letters. The superscripts

Consider an uplink multiuser MIMO wireless system with an

Block diagram of an uplink multiuser MIMO wireless system with an

The MIMO channels among users are assumed to be independent and flat fading. The uplink CSI model at the BS can be expressed as

With the CSI model, the received signal vector at the BS is written as

Given a set of precoders

The QR-EPD noniterative algorithm.

(1) First, the QR factorization is employed to perform the decomposition of the matrix | |

(2) A simple QR-based scheme [ | |

(3) The matrix | |

(4) As the matrix | |

(5) Finally, the EPD scheme is utilized to perform factorization of |

In this section, computer simulations are conducted to demonstrate the performance of the proposed QR-EPD transceiver design as developed in Section

In Figure

(a) The SMSE and (b) the averaged BER comparisons between the proposed QR-EPD, the SVD-EPD, the SVD non-EPD, and the KKT algorithms for

Results of Figures

(a) The SMSE and (b) the averaged BER comparisons between the proposed QR-EPD, the SVD-EPD, the SVD non-EPD, and the KKT algorithms for

(a) The SMSE and (b) the averaged BER comparisons between the proposed QR-EPD, the SVD-EPD, the SVD non-EPD, and the KKT algorithms for

In this paper, a joint linear precoder-decoder pair is considered for uplink multiuser MIMO wireless systems with limited CSI at both the transmitters and the receivers. Instead of counting on complex iterative-based algorithms, the computationally efficient noniterative QR-based linear transceiver pair is proposed. In addition, an EPD scheme is applied to adjust transmit power allocation of each mobile station between its symbols under the sum-power constraint. Simulation results, compared with those of the existing iterative-based transceiver designs, have shown that the proposed QR-EPD scheme is capable of achieving a superior SMSE and enhance the average BER performance simultaneously without compromising the computational complexity.