Multiuser scheduling is an important aspect in the performance optimization of a wireless network since it allows multiple users to access a shared channel efficiently by exploiting multiuser diversity. To perform efficient scheduling, channel state information (CSI) for users is required, and is obtained via their respective feedback channels. In this paper, a more realistic imperfect CSI feed...

A practical multiuser cooperative transmission scheme denoted as Virtual Maximum Ratio Transmission (VMRT) for multipleinput multiple-output-orthogonal frequency division multiple access (MIMO-OFDMA) relay-based networks is proposed and evaluated in the presence of a realistic channel estimation algorithm and using low-density parity-check (LDPC) codes. It is shown that this scheme is robust ag...

In high dynamic conditions, using vector tracking loops instead of scalar tracking loops in GPS receivers is proved as an efficient method to compensate the performance. The Minimum Mean Squared Error detector as a multiuser detector is applied in the vector tracking loop for more reliability and efficiency. The Kalman filter does the two tasks of tracking and extracting the navigation data aft...

CDMA system perjbrmance can be enhanced by interference management techniques. We consider the uplink o j a CDMA system that employs two such techniques: temporal multiuser detection and spatial antenna array heamjhrming. Recently, temporal-spatial MMSE vpe receivers with several diflerent criteria have been proposedjor a static channel. In this work, we consider such MMSEjlter.7 assuming a mul...

We consider the problem of simultaneous parameter estimation and data restoration in a synchronous CDMA system in the presence of either additive Gaussian or additive impulsive white noise with unknown parameters. The impulsive noise is modeled by a two-term Gaussian mixture distribution. Bayesian inference of all unknown quantities is made from the superimposed and noisy received signals. The ...

In this paper, the error performance of multiuser CDMA system with space-time coding is studied in Rician fading channel, and the corresponding bit error rate (BER) and symbol error rate (SER) analysis are presented. Based on the performance analysis, a simple and effective multiuser receiver scheme is developed. The scheme has linear decoding complexity when it compares to the existing scheme....

This report investigates channel modeling and estimation for a wired multiuser multicarrier communications system. The special case of a multiple-input multiple-output (MIMO) channel is considered where the different users transmit at the same time and over the same bandwidth. In the report, I will introduce data transmission and training systems. The report also will present a MIMO channel mod...

In multiple-access communication systems several users share the system resources, thus creating cochannel interference to each other. Multiuser detection, applied at the receiver side, is a powerful technique to combat co-channel interference, in contrast to single-user approaches that treat the interference as additive noise. In this paper, we investigate the feasibility of achieving increase...

Signals transmitted through multiple-input multiple-output (MIMO) wireless channels suffer from multiple-access interference (MAI), multipath propagation and additive noise. Iterative multiuser receiver algorithms mitigate these signal impairments, while offering a good tradeoff between performance and complexity. The receiver presented in this paper performs channel estimation, multiuser detec...

| Space-time coding and interference cancellation based on orthogonal projection are powerful techniques to improve the communication quality and capacity in downlink CDMA systems. Space-time encoder output stream is transmitted through fading channel using multiple transmitter antennas, increasing communication reliability against multipath fading. On the other hand, orthogonal projection-base...