scholarly journals Information Bottleneck for a Rayleigh Fading MIMO Channel with an Oblivious Relay

Information ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 155
Author(s):  
Hao Xu ◽  
Tianyu Yang ◽  
Giuseppe Caire ◽  
Shlomo Shamai (Shitz)
Keyword(s):  
Upper Bound ◽  
Rayleigh Fading ◽  
Mimo Channel ◽  
Destination Node ◽  
Information Bottleneck ◽  
Channel Input ◽  
Perfect Channel State Information ◽  
Wide Range ◽  
Channel Realization ◽  
Channel Dimension

This paper considers the information bottleneck (IB) problem of a Rayleigh fading multiple-input multiple-out (MIMO) channel with an oblivious relay. The relay is constrained to operating without knowledge of the codebooks, i.e., it performs oblivious processing. Moreover, due to the bottleneck constraint, it is impossible for the relay to inform the destination node of the perfect channel state information (CSI) in each channel realization. To evaluate the bottleneck rate, we first provide an upper bound by assuming that the destination node can obtain a perfect CSI at no cost. Then, we provide four achievable schemes, where each scheme satisfies the bottleneck constraint and gives a lower bound to the bottleneck rate. In the first and second schemes, the relay splits the capacity of the relay–destination link into two parts and conveys both the CSI and its observation to the destination node. Due to CSI transmission, the performance of these two schemes is sensitive to the MIMO channel dimension, especially the channel input dimension. To ensure that it still performs well when the channel dimension grows large, in the third and fourth achievable schemes, the relay only transmits compressed observations to the destination node. Numerical results show that, with simple symbol-by-symbol oblivious relay processing and compression, the proposed achievable schemes work well and can demonstrate lower bounds that come quite close to the upper bound on a wide range of relevant system parameters.

scholarly journals Capacity of fully correlated MIMO system using character expansion of groups

2005 ◽  
Vol 2005 (15) ◽  
pp. 2461-2471 ◽  
Author(s):  
Ejaz Khan ◽  
Conor Heneghan
Keyword(s):  
Antenna Arrays ◽  
Rayleigh Fading ◽  
Mimo Systems ◽  
Mimo System ◽  
Mimo Channel ◽  
Communication Link ◽  
Channel State ◽  
State Information ◽  
Perfect Channel State Information ◽  
Propagation Medium

It is well known that the use of antenna arrays at both sides of communication link can result in high channel capacities provided that the propagation medium is rich scattering. In most previous works presented on MIMO wireless structures, Rayleigh fading conditions were considered. In this work, the capacity of MIMO systems under fully correlated (i.e., correlations between rows and columns of channel matrix) fading is considered. We use replica method and character expansions to calculate the capacity of correlated MIMO channel in closed form. In our calculations, it is assumed that the receiver has perfect channel state information (CSI) but no such information is available at the transmitter.

Capacity of Bernoulli-Gaussian Interference Channels in Rayleigh Fading with Full CSI

2015 ◽  
Vol 1 ◽  
pp. 53
Author(s):  
Anh D. Le ◽  
Hung V. Vu ◽  
Nghi H. Tran ◽  
Vo Nguyen Quoc Bao
Keyword(s):  
Lower Bound ◽  
Closed Form ◽  
Channel Capacity ◽  
Upper Bound ◽  
Rayleigh Fading ◽  
Piecewise Linear ◽  
Upper And Lower Bounds ◽  
Wide Range ◽  
Power Adaptation ◽  
Adaptation Scheme

In this paper, we investigate the channel capacity of a Bernoulli-Gaussian (BG) interference channel in Rayleigh fading when the channel state information (CSI) is known at both the transmitter and receiver via tight lower and upper bounds. Specifically, we first derive an upper bound on the channel capacity assuming a Gaussian-distributed output. Under this assumption, an optimal power adaptation scheme is established and the upper-bound is obtained in closed-form. By assuming a Gaussian-distributed input, we then adopt the derived power adaptation scheme to establish a lower bound on channel capacity. A simple approximation of the instantaneous output entropy using a piecewise-linear curve fitting(PWLCF)-based scheme is then developed, which provides a closed-form estimation of the lower bound with a predetermined error level. Finally, a comparison between the derived upper and lower bounds are made. Both analytical and numerical results show that these two bounds are tight in a wide range of input power levels and they can be used effectively to estimate the channel capacity.

Radial Flow Velocity Field for Predicting Upper-Bound Solutions for Plane Strain Extrusion

1968 ◽  
Vol 90 (1) ◽  
pp. 45-50
Author(s):  
R. G. Fenton
Keyword(s):  
Velocity Field ◽  
Flow Field ◽  
Flow Velocity ◽  
Plane Strain ◽  
Upper Bound ◽  
Radial Flow ◽  
Flow Velocity Field ◽  
Wide Range ◽  
Ram Pressure ◽  
Considerable Range

The upper bound of the average ram pressure, based on an assumed radial flow velocity field, is derived for plane strain extrusion. Ram pressures are calculated for a complete range of reduction ratios and die angles, considering a wide range of frictional conditions. Results are compared with upper-bound ram pressures obtained by considering velocity fields other than the radial flow field, and it is shown that for a considerable range of reduction ratios and die angles, the radial flow field yields better upper bounds for the average ram pressure.

Scaling laws for delay-sensitive traffic in Rayleigh fading networks

2008 ◽  
Vol 464 (2096) ◽  
pp. 2187-2205 ◽  
Author(s):  
Nikhil Karamchandani ◽  
Massimo Franceschetti
Keyword(s):  
Rayleigh Fading ◽  
Scaling Laws ◽  
Scaling Limit ◽  
Network Size ◽  
Upper And Lower Bounds ◽  
Destination Node ◽  
Delay Constraint ◽  
Delay Sensitive ◽  
Remote Surveillance ◽  
Emergency Scenarios

The throughput of delay-sensitive traffic in a Rayleigh fading network is studied by adopting a scaling limit approach. The case of the study is that of a pair of nodes establishing a data stream that has routing priority over all the remaining traffic in the network. For every delay constraint, upper and lower bounds on the achievable information rate between the two endpoints of the stream are obtained as the network size grows. The analysis concerns decentralized schemes , in the sense that all nodes make next-hop decisions based only on local information, namely their channel strength to other nodes in the network and the position of the destination node. This is particularly important in a fading scenario, where the channel strength varies with time and hence pre-computing routes can be of little help. Natural applications are remote surveillance using sensor networks and communication in emergency scenarios.

scholarly journals A Constellation Space Dimensionality Reduced Sub-Optimal Receiver for Orthogonal STBC CPM Modulation in a MIMO Channel

10.14311/1107 ◽  
2009 ◽  
Vol 49 (2) ◽  
Author(s):  
M. Hekrdla
Keyword(s):  
Rayleigh Fading ◽  
Dimensional Subspace ◽  
Space Time ◽  
Mimo Channel ◽  
Optimal Receiver ◽  
Computational Performance ◽  
Awgn Channel ◽  
Serially Concatenated ◽  
Optimal Subspace ◽  
Subspace Search

We consider burst orthogonal space-time block coded (OSTBC) CPM modulation in a MIMO flat slow Rayleigh fading channel. The optimal receiver must process a multidimensional non-linear CPM signal on each antenna. This task imposes a high load on the receiver computational performance and increases its complexity. We analytically derive a suboptimal receiver with a reduced number of front end matched filters (MFs) corresponding to the CPM dimension. Our derivation is made fully in the constellation signal space, and the reduction is based on the linear orthogonal projection to the optimal subspace. Criterion optimality is a standard space-time rank and determinant criterion. The optimal arbitrary-dimensional subspace search leads to the eigenvector solution. We present the condition on a sufficient subspace dimension and interpret the meaning of the corresponding eigenvalues. It is shown that the determinant and rank criterion for OSTBC CPM is equivalent to the uncoded CPM Euclidean distance criterion. Hence the proposed receiver may be practical for uncoded CPM and foremost in a serially concatenated (SC) CPM system. All the derivations are supported by suitable error simulations for binary 2REC h= 1/2, but the procedure is generally valid for any CPM variant. We consider OSTBC CPM in a Rayleigh fading AWGN channel and SC CPM in an AWGN channel. 

scholarly journals A Deterministic Construction for Jointly Designed Quasicyclic LDPC Coded-Relay Cooperation

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Asif ◽  
Wuyang Zhou ◽  
Qingping Yu ◽  
Xingwang Li ◽  
Nauman Ali Khan
Keyword(s):  
Fading Channels ◽  
Iterative Decoding ◽  
Rayleigh Fading ◽  
Additive White Gaussian Noise ◽  
Ldpc Codes ◽  
Destination Node ◽  
Relay Nodes ◽  
Binary Matrix ◽  
Relay Cooperation ◽  
Joint Iterative Decoding

This correspondence presents a jointly designed quasicyclic (QC) low-density parity-check (LDPC) coded-relay cooperation with joint-iterative decoding in the destination node. Firstly, a design-theoretic construction of QC-LDPC codes based on a combinatoric design approach known as optical orthogonal codes (OOC) is presented. Proposed OOC-based construction gives three classes of binary QC-LDPC codes with no length-4 cycles by utilizing some known ingredients including binary matrix dispersion of elements of finite field, incidence matrices, and circulant decomposition. Secondly, the proposed OOC-based construction gives an effective method to jointly design length-4 cycles free QC-LDPC codes for coded-relay cooperation, where sum-product algorithm- (SPA-) based joint-iterative decoding is used to decode the corrupted sequences coming from the source or relay nodes in different time frames over constituent Rayleigh fading channels. Based on the theoretical analysis and simulation results, proposed QC-LDPC coded-relay cooperations outperform their competitors under same conditions over the Rayleigh fading channel with additive white Gaussian noise.

scholarly journals An Investigation of Self-Interference Reduction Strategy in a Spatially Correlated MIMO Channel

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Rosdiadee Nordin
Keyword(s):  
Fading Channels ◽  
Multiple Input Multiple Output ◽  
Spatial Multiplexing ◽  
Mimo Channel ◽  
Limiting Factor ◽  
Subcarrier Allocation ◽  
Spatially Correlated ◽  
High Data ◽  
Correlated Channels ◽  
Wide Range

One of the efficient ways to transmit high data rate is by employing a multiple-input multiple-output (MIMO) transmission. One of the MIMO schemes, known as spatial multiplexing (SM), relies on the linear independence data streams from different transmit antennas to exploit the capacity from the fading channels. Consequently, SM suffers from the effect of spatial correlation which is the limiting factor in achieving the capacity benefit that SM can offer. In an attempt to increase the robustness of the SM transmission in a wide range of correlated channels, the use of dynamic subcarrier allocation (DSA) is investigated. The effective signal-to-interference-and-noise ratio (SINR) metric is used as the performance metric to determine the subcarrier quality which can then be utilised in the allocation. Two novel variants of the subcarrier allocation scheme are proposed. It is shown that the DSA-SINR approach improves the BER performance of SM transmission in highly correlated channels environment.

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