We evaluate the optical gain achieved in an indoor optical wireless (OW) channel when increasing the number of branches of the angle diversity receiver from three to seven. Simulation is carried out for five different spot diffusing geometries as to compare the systems' performance when the square-base three branch angle diversity receiver is replaced by a hexagonalbase and seven-branch design....

Transmit diversity techniques provide attractive solutions for increasing downlink capacity in 3G systems within low-mobility environments. Open-loop and closed-loop transmit diversity modes with two transmit antennas have already been included into 3GPP WCDMA Release 4, and at the moment schemes exploiting a larger number of transmit antennas are being developed. This paper analyzes the perfor...

The impact of diversity combining on the matched filter bound of BPSK on time-discrete multipath slowly Rayleigh fading intersymbol interference channels is analysed. Expressions for the bound are derived for SNR selection, S+N selection, and also equal gain diversity combining. Numerical results for the derived bounds are presented on a GSM typical urban channel model.

In this paper, we propose a novel interleave division multiplexing(IDM) cooperative diversity scheme and we look about some properties of the proposed scheme. The proposed scheme is flexible and has low relay complexity. We also propose a power allocation algorithm. Simulation results show that the proposed scheme achieves diversity gain and the performance is further increased with the propose...

This paper addresses possible capacity gains in a cdma2000 1xEV-DO system that utilizes the Opportunistic Beam Forming (OBF) scheme. Contrary to the voice-oriented cdma2000 systems, where it is desirable to maintain a fixed signal-to-interference-and-noise ratio (SINR) level at the access terminal (AT), the 1xEV-DO system is designed to take advantage of the natural SINR fluctuations in a wirel...

In the recent landmark paper of Zheng and Tse it is shown that there exists a fundamental tradeoff between diversity gain and multiplexing gain, referred to as the Diversity-Multiplexing gain(D-MG) tradeoff. It is shown in [5] that ST codes with non-vanishing determinant (NVD) constructed from cyclic-divisionalgebras (CDA), are optimal under the D-MG tradeoff for any number nt, nr of transmit a...

Relays form a distributed antenna system that can be used for extending the coverage of wireless OFDM networks in a cost-efficient manner. We consider a general network where Nr parallel relay nodes (RNs) amplify and forward signals from a base station (BS). Multipath fading is beneficial for OFDM transmission as it increases frequency selectivity which can be exploited by forward error control...

Cooperative diversity is a transmission technique where multiple users pool their resources to form a virtual antenna array that realizes spatial diversity gain in a distributed fashion. In this paper, we examine space-time signal design for a simple amplify-and-forward relay channel. We show that the code design criteria for the relay case consist of the traditional rank and determinant criter...

Cooperative spatial multiplexing (CSM) system has played an important role in wireless networks by offering a substantial improvement in multiplexing gain compared with its cooperative diversity counterpart. However, there is a limited number of research works that consider the performance of CSM systems. As such, in this paper, we have derived exact performance of CSM with amplify-and-forward ...

This paper investigates rate adaptation schemes for decoding-and-forward (DF) relay system based on random projections codes (RPC). We consider a classic three node relay system model, where relay node performs on half-duplex mode. Then, we give out receiving diversity relay scheme and coding diversity relay scheme, and present their jointly decoding methods. Furthermore, we discuss the perform...