We propose in this paper as a possible candidate for next-generation WiMAX a multilayer spatial multiplexing scheme, which is flexible and conceptually simple. Every layer is a QPSK symbol stream, weighted by a coefficient, and superimposed on the other layers. A method to optimize the coefficients is described in details. At the receiver, an iterative (turbo-like) structure gives very good per...

In this paper, a numberof ultrawideband (UWB)multiple-inputmultiple-output (MIMO) spatialmultiplexing systems are presented and their error performance is analysed. For both model-based and measured UWB channels, the performance of various MIMO detectors is evaluated under the multiband orthogonal frequency division multiplexing (MB-OFDM) regime. Contrary to expectation, the results demonstrate...

Space-frequency coded Orthogonal Frequency Division Multiplexing (OFDM) is capable of realizing both spatial and frequency-diversity gains in multipath multiple-input multipleoutput (MIMO) fading channels. This naturally leads to the question of variable allocation of the channel’s degrees of freedom to multiplexing and diversity transmission modes. In this paper, we provide a systematic method...

This paper combines spatial Tomlinson-Harashima (TH) precoding with packet scheduling at the transmitter to improve the system-level performance of packet data systems. Under the assumptions of instantaneous and perfect channel state information (CSI) at the transmitter and independent and identically distributed (i.i.d.) user channels with flat fading, the spatially equalized and decoupled mul...

Spatial modulation (SM) is a transmission scheme where only one transmit antenna is active at any time instant. It thus reduces interchannel interference (ICI) and receiver complexity over traditional multi-antenna systems. However, the spectral efficiency of SM is low. To improve the spectral efficiency, generalized spatial modulation (GSM) can be used. In this paper, we propose to apply the A...

Using a class of recently proposed linear scalable space-time codes we demonstrate the tradeoff between spatial multiplexing and transmit diversity for Rayleigh and Ricean flat fading. The codes are able to use jointly transmit diversity in combination with spatial multiplexing, and they achieve spatial and temporal diversity in Rayleigh and Rice fading environments. Frequency diversity of freq...

Spatial multiplexing multiple-input multiple-output (MIMO) wireless systems are of both theoretical and practical importance because they can achieve high spectral efficiencies by demultiplexing the incoming bit stream into multiple substreams. It has been shown that sending fewer substreams than the number of transmit antennas by linear precoding can provide improved error rate performance. Me...

A fast near-optimal transmission scheme selection algorithm for multiple-input multiple-output (MIMO) systems using spatial multiplexing and linear detection is proposed and analyzed. The algorithm selects a transmit antenna subset such that applying available coding and modulation (CM) modes on each spatially multiplexed substream optimises the throughput under constraints on maximum expected ...

MIMO has great potential for enhancing the throughput of multi-hop wireless networks via spatial multiplexing or spatial reuse techniques. Spatial reuse outperforms spatial multiplexing in terms of potential network throughput and is effective in a wider range of wireless contexts than spatial multiplexing. The network throughput when previous approaches of spatial reuse are employed, however, ...

Future wireless communication systems will demand high data rates for delivery of data like multimedia content. The use of MIMO systems with multiple transmit and receive antennas enables the introduction of space-time coding to improve link reliablity and spatial multiplexing to increase spectral efficiency. Recently a class of codes was proposed in [14] which makes it possible to combine spac...