Nonlinear precoding schemes for downlink time-division duplex–CDMA systems over multipath fading channels, are considered. First, the capacity results of a downlink CDMA system with either multiuser detection or precoding, were obtained and compared. It is seen that the two schemes exhibit similar capacity regions for both sum rate and maximum equal rate, which motivates the development of effi...

Massive multiple-input multiple-output (MIMO) is envisioned to offer a considerable improvement in capacity, but it has a high cost and the radio frequency (RF) chain components have a high power consumption at high frequency. To address this problem, a hybrid analog and digital precoding scheme has been studied recently, which restricts the number of RF chains to far less than the number of an...

This paper proposes a new MIMO-OFDM precoding technique that aims to minimize a bit error rate (BER) upper bound of the maximum likelihood detection (MLD) in mobile radio communications. Using a steepest descent algorithm, the proposed method estimates linear precoding matrices that can minimize the upper bound of BER under power constraints. Since the upper bound is derived from all the pairwi...

This paper presents an improved version of precoding, i.e., nonlinear preequalization, for situations with one central transmitter (e.g., base station) and a number of distributed receivers (e.g., mobile terminals). The new method is based on Tomlinson-Harashima precoding, applied to multipleinput/multiple-output (MIMO) channels, and inspired by the concept of lattice-reduction-aided detection ...

This paper addresses the problem of decoding and precoding in the K-user MIMO interference channels. At the receiver side, a joint decoding of the interference and the desired signal is able to improve the receive diversity order. At the transmitter side, we introduce a joint linear precoding design that maximizes the joint cut-off rate, known as a tight lower bound on the joint mutual informat...

Compound precoding is a state-of-the-art technique for combining trellis coding and decision-feedback equalisation (DFE) prior to upstream transmission on the telephone-line channel, and is an option in the International Telecommunications Union (ITU)-T V.92 standard. In this paper, we provide a detailed overview of this technique. We demonstrate that compound precoding combines in a straightfo...

In this paper, we study unitary precoding for multistream MIMO systems with partial channel state information at the transmitter. We consider the full space of non-equivalent unitary precoding matrices which can be divided into two parts, Grassmmannian precoding and orthogonalizing precoding. The parts have different role and relevance depending on the scenario. In case of limited feedback, the...

Recently, there has been considerable interest in cooperative multiple-input multiple-output (MIMO) systems, where the data intended for a user equipment (UE) is simultaneously transmitted from multiple base stations (BSs). In [1], the authors investigated cooperative MIMO as a means to mitigate co-channel interference and to exploit macro-diversity for the Wyner’s model and its variants. Moreo...

A downlink adaptive distributed precoding scheme is proposed for coordinated multi-point (CoMP) transmission systems. The serving base station (BS) obtains the optimal precoding vector via user feedback. Meanwhile, the precoding vector of each coordinated BS is determined by adaptive gradient iteration according to the perturbation vector and the adjustment factor based on the vector perturbati...

The project involves utilization of various precoding techniques such as block-diagonalization (BD), block-diagonalization dirty paper coding (BD-DPC) in a multiuser system on a per-cell basis considering a multicell scenario. The multicell system is been analysed and examined using two modes of operation called competition and coordination. In the former mode, an approach named as noncooperati...