The average channel capacity and the SINR distribution for multiuser Multiple Input Multiple Output (MIMO) systems in combination with the base station based packet scheduler are analyzed in this paper. The packet scheduler is used to exploit the available multiuser diversity in all the three physical domains (i.e., space, time and frequency). The analysis model is based on the generalized 3GPP...

The channel capacity of randomly spread CDMA subject to Gaussian noise and flat fading is studied in the large-system limit under arbitrary input distributions. Using the replica method originally developed in statistical physics, we find the spectral efficiencies under both joint decoding and single-user decoding. We show that under single-user decoding, where a conditional mean estimator is f...

This paper presents efficient algorithms and architecture designs that can meet real-time requirements of multiuser channel estimation and detection in future wireless base-station receivers. Sophisticated algorithms proposed to implement multiuser channel estimation and detection make their real-time implementation difficult on current Digital Signal Processor (DSP)-based receivers. A maximum-...

Multiuser diversity (MD), as a fundamental property of fading wireless networks, has been widely applied in today’s wireless communication systems. In this letter, we consider the newly emerging cognitive radio (CR) wireless network that communicates by sharing the spectrum with the existing primary radio (PR) network. Under the assumption that the CR transmit terminal protects the PR transmiss...

A collision frequency shift keyed system (CFSK) using M-ary FSK signaling is investigated. CFSK is a wireless multiple access system in which users access a channel without cooperation. This results in collisions when users simultaneously transmit signals in the same frequency band. However, analysis has shown that the CFSK system has the potential to achieve greater capacities than binary mult...

In order to solve the high sampling rate issue in the multiuser UWB communication network system, we process the received signal with Bayesian compressive sensing. Using the characteristic that the wireless channels of multiuser signals which are received by one receiver at the same time are statistically related, a Laplace prior based distributed Bayesian compressive sensing method is proposed...

The discovery of Turbo Codes in 1996 by Berrou et. al. proved to be a huge boost for the research of channel coding. The Turbo Principle behind turbo codes was found to be applicable in other areas. One of these areas is Multiuser Detection. In this thesis, Turbo Multiuser Detection is investigated in order to answer two main questions. The questions concern the performance gain that is obtaine...

This paper presents a new subband allocation scheme for multiuser OFDMA systems. Adaptive OFDMA systems have focused on adapting the allocation of subcarriers and power to the instantaneous channel conditions of all users. Using frequency hopping pattern in OFDMA system allow users to minimize intercell and intracell interference, and perform frequency diversity. In contrast to conventional FH-...

An orthogonal decomposition of a general wideband space-time multipath channel is derived assuming antenna arrays at both the transmitter and receiver. Knowledge of channel state information is assumed at both the transmitter and receiver. The decomposition provides a framework for efficiently managing the degrees of freedom in the space-time channel to optimize any combination of bit-error rat...

We consider transmitter precoding for interference suppression and diversity exploitation for multi-antenna CDMA. The receivers are constrained to matched filter detection without channel state information (CSI) or receiver-based multiuser detection. We first develop precoders for scenarios where perfect downlink channel information is available at the transmitter. We show that full transmit an...