There is a trend for mobile satellite system architectures aimed at the deployment of multi-satellite constellations in Non-Geostationary Earth Orbits (NGEOs). This allows the user terminals to be small size, low cost and having low power demand. In present and next generation satellite systems, CDMA has been proposed as the multiple access technique for a number of mobile satellite communicati...

The interfering source in a two-user Z-channel can use either singleuser (SU) codes or rate splitting (RS) based multi-user codes. The RS codes are known to achieve better sum-rate than the SU codes. However, if the individual user’s reliability requirements are considered in a two-user Z-channel, it is unknown whether the RS codes achieve better performance than SU codes. To this end, the dive...

This paper presents a basic investigation of the power imbalance problem with regard to maximum ratio combining (MRC) array antennas for digital TV broadcast reception. First, the relationship between the decrease in the diversity gain and reduction in the received power was investigated using two-element and four-element dipole array antennas by means of a Monte Carlo simulation. The relations...

This paper proposes a novel signal scheme called “Hybrid BLAST STBC approach” this combines MIMO (multiple-input multiple-output) and STBC (space time block code) to generate a system functionally superior to MIMO and STBC systems. This paper compares and investigates the capacity of high data rate wireless local area network systems using MIMO techniques. In particular, two different algorithm...

The motivation of the present study is to investigate the possibility of using two independently directed antenna beams in a mobile base station to provide diversity gain and reduce fading problems in a microcellular environment. In this paper, the signal correlation of the individual antenna beams is studied, and it is shown that correlation depends on beamwidth, separation angle of the antenn...

In cellular Wideband Code Division Multiple Access (WCDMA) networks, interference on the uplink is the limiting factor for the number of users that can be served in a single cell. Thus, interference reduction mechanisms are of significant importance. Soft handover, which is primarily a mechanism for seamless handovers (make before break), also reduces the interference within the cells by exploi...

The diversity multiplexing tradeoff of a general two-hop asynchronous cooperative network is examined for various relaying protocols such as non-orthogonal selection decode-and-forward (NSDF), orthogonal selection decodeand-forward (OSDF), non-orthogonal amplify-and-forward (NAF), and orthogonal amplify-and-forward (OAF). The transmitter nodes are assumed to send pulse amplitude modulation (PAM...

In this paper, we explore the fundamental performance tradeoff of the delay-limited Multi-InputMulti-Output (MIMO) Automatic Retransmission reQuest (ARQ) channel. In particular, we extend the diversity-multiplexing tradeoff investigated by Zheng and Tse in standard delay-limited MIMO channels with coherent detection to the ARQ scenario. We establish the three-dimensional tradeoff between reliab...

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...