Recently, the finite state Markov channel (FSMC) with an additional eavesdropper and delayed feedback from the legitimate receiver to the transmitter has been shown to be a useful model for the physical layer security of the practical mobile wireless communication systems. In this paper, we extend this model to a multiple-access situation (up-link of the wireless communication systems), which w...

When a feedback channel is available from the receiver to the transmitter, adaptive schemes for source-channel coding can be used for image transmission. In this paper we see that the use of embedded source codes and embedded channel codes, when combined in a Hybrid ARQ protocol, can provide the desired exibility at high eeciency, low complexity and low feedback channel usage. We propose optimi...

In this paper, partial feedback schemes for a multiple input multiple output orthogonal frequency division multiple access system using a random beamforming are analyzed and optimized. For partial feedback schemes, the partial channel quality indicator feedback schemes and the partial channel quality rank indicator feedback schemes are considered. For these schemes, we first derive the effectiv...

This paper summarizes recent results on the multiple antenna broadcast (downlink) channel with finite rate feedback of channel state information from each receiver. In this model, the receivers are assumed to have perfect channel knowledge, while the transmitter gains channel knowledge through a finite rate feedback channel from each receiver. The SNR degradation as a function of the feedback r...

This work studies the performance of our recently proposed differential feedback scheme for multi-input-multi-output (MIMO) communication systems using real channel measurement data. The algorithm is applied to the channel correlation matrix exploiting geodesic curves and the intrinsic geometry of positive definite Hermitian matrices. The performance of this and a conventional non-differential ...

An opportunistic feedback protocol is proposed for orthogonal frequency division multiple access (OFDMA) systems with mixed realtime (RT) and non-realtime (NRT) traffic. This protocol allocates a dedicated feedback channel for each RT user, while it allows all NRT users to compete to send feedback via a contention-based random access feedback channel. The proposed feedback protocol requires a f...

For information transmission a discrete time channel with independent additive Gaussian noise is used. There is also feedback channel with independent additive Gaussian noise, and the transmitter observes without delay all outputs of the forward channel via that feedback channel. Transmission of nonexponential number of messages is considered and the achievable decoding error exponent for such ...