Hybrid precoding can significantly reduce the number of required radio frequency (RF) chains and relieve the huge energy consumption in mmWave massive MIMO systems, thus attracting much interests from academic and industry. However, most existing hybrid precoding schemes are based on singular value decomposition (SVD). Due to the very different subchannel signal-to-noise ratios (SNRs) after SVD...

In this paper, we propose successive optimization non-linear precoding strategies for physical-layer security in wireless networks. We also investigate different precoding techniques for multi-user MIMO systems under various conditions of channel state information (CSI) between the access point and the users and the eavesdroppers. A nonlinear precoding technique based on Successive Optimization...

This paper presents linear and nonlinear precoding design for error-rate improvement in orthogonal space–time block-coded (OSTBC) multiple-input–multiple-output (MIMO) orthogonal frequency-division-multiplexed (OFDM) downlink, where both the conditional mean of the channel gain matrix and the channel gain covariance matrix may be available at the transmitter. The conditional means of the channe...

The use of low-resolution digital-to-analog converters (DACs) for transmit precoding provides crucial energy efficiency advantage for massive multiple-input multiple-output (MIMO) implementation. This paper formulates a quadrature amplitude modulation (QAM) constellation range and one-bit symbol-level precoding design problem for minimizing the average symbol error rate (SER) in downlink massiv...

Linear precoding techniques can achieve nearoptimal capacity due to the special channel property in downlink massive MIMO systems, but involve high complexity since complicated matrix inversion of large size is required. In this paper, we propose a low-complexity linear precoding scheme based on the Gauss-Seidel (GS) method. The proposed scheme can achieve the capacity-approaching performance o...

|Precoding at the transmitter side is a practicable method for transmission over intersymbol interference channels. In contrast to decision{feedback equalization no error propagation occurs and coded modulation can be applied as for the intersymbol interference free channel. In this paper, Tomlinson{Harashima precoding and exible precoding are analyzed and compared. The dualities and di erences...

Space division multiple access (SDMA) promises high gains in the system throughput of wireless multiple antenna systems. If SDMA is used on the downlink of a multi-user multiple-input multiple-output (MIMO) system, either long-term or shortterm channel state information has to be available at the base station (BS) to facilitate the joint precoding of the signals intended for the different users...

This study proposes a novel precoding scheme for multiuser multiple-input multiple-output (MIMO) relay systems in the presence of imperfect channel state information (CSI). The base station (BS) and the MIMO relay station (RS) are both equipped with the same codebook of unitary matrices. According to each element of the codebook, we create a latent precoding matrix pair, namely a BS precoding m...

In this paper, a novel precoding scheme based on the operations in Galois Field of size q = 2 (GF (q)) is proposed. In the proposed precoding scheme, the original finite modulated symbols are represented by elements in GF (q), and a precoding matrix with each element also selected from GF (q) is generated; With the operations defined in GF (q), the correlation among the symbols that are similar...

We investigate precoding of the information symbols before spreading for downlink DS-CDMA systems subject to multipath fading. With precoding, a conventional receiver (RAKE) can achieve performance comparable to other suboptimal multiuser receivers, e.g. MMSE and ZF. We extend the work in [1] regarding constrained precoding for multipath channels and present closed form solutions. Through simul...