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TDD multiuser downlink MIMO channels with delayed channel state information at the transmitter (CSIT) are considered. Block diagonalization is applied at the base station (BS). In order to cope with the inter-user interference caused by the delayed CSIT, we develop a novel capacity estimation method at first and then propose robust delayed CSIT aware multimode selection schemes based on the estimation...
The performance of spatial multiplexing systems with linear minimum-mean-squared-error receivers is investigated in ad hoc networks. We present new exact closed-form expressions for the outage probability and transmission capacity. These expressions reveal that from a transmission capacity perspective, single-stream transmission is preferable over multi-stream transmission.
An ultra-high data rate Time Reversal (TR) Multiple-Input Multiple-Output (MIMO) Ultra-Wideband (UWB) communication system with space-time pre-equalizer is proposed. When the symbol duration is set to approach the duration of UWB monocycles, the data rate is close to the limit due to the extremely large bandwidth, resulting in the severe intersymbol interference (ISI). The zero-forcing (ZF)criterion...
Among the techniques proposed to reduce interference in cellular ODFMA networks, base station cooperation (BSC) is currently the technique known to achieve the highest network throughputs. Its deployment however is vastly expensive and cheaper alternatives are expected to play an important role in future wireless access standards. This contribution introduces relay-augmented networks based on the...
Consider the max-min fairness linear transceiver design for a multi-user MIMO interference channel. Assuming perfect channel knowledge, this problem can be formulated as the maximization of minimum SINR utility, subject to individual power constraints at each transmitter. In this paper, it is shown that when the number of antennas at each transmitter (receiver) is at least two and at each receiver...
Transmit diversity schemes with multiple streams obtain reliable transmission but suffer from interference when decoding multiple streams simultaneously. In this paper, we present closed-loop space-time block codes for multiple streams with limited channel information in order to ease suppressing interference at a receiving station. The proposed scheme includes constellation rotation in Alamouti coding...
We solve the rate balancing problem in the downlink for a multiuser multiple-input-multiple-output (MIMO) system with multiple linear transmit covariance constraints. In particular, we adopt a linear transceiver structure to maximize the worst-case rate of the user while satisfying multiple linear transmit covariance constraints. The original rate balancing problem in the downlink is more complicated...
In this paper, we propose a new downlink multi-user multiple-input multiple-output (MIMO) precoding scheme based on maximizing the successive signal to leakage plus noise ratio (SSLNR). The work is motivated by the precoding scheme developed by Sadek, Tarighat and Sayed by maximizing the signal to leakage plus noise ratio (SLNR), which does not impose any restriction on the number of antennas at the...
In this paper, we develop linear precoding methods for cognitive radio (CR) multi-user multiple-input multiple-output (MU-MIMO) broadcast systems where unlicensed secondary users (SUs) simultaneously use the same spectrum of the licensed primary user (PU). When the zero-forcing block diagonalization (ZF-BD) precoder is extended to the CR network, a noise enhancement problem occurs. Therefore, we propose...
This paper addresses bounds on the transmission capacities of two coexisting wireless networks (a primary and a secondary network), where each with multiple antennas shares the same spectrum and operates in the same geographic region. In the two coexisting network, the secondary (SR) network limits its interference to the primary (PR) network by carefully controlling its active transmitter density...
An asymptotic technique is developed to find the Signal-to-Interference-plus-Noise-Ratio (SINR) and spectral efficiency of a link with N receiver antennas in wireless networks with non-homogeneous distributions of nodes. It is found that with appropriate normalization, the SINR and spectral efficiency converge with probability 1 to asymptotic limits as N increases. This technique is applied to networks...
In this paper, we evaluate the impact of a mix of co-channel MIMO interferers on the performance of Alamouti Coding in the downlink of a cellular-like system. In particular, taking into account the effects of both path-loss and Rayleigh fading, we derive closed-form expressions for the probability density functions of the resulting signal-to-interference ratios. Simulation results verify the validity...
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