scholarly journals Power Optimization of Tilted Tomlinson-Harashima Precoder in MIMO Channels with Imperfect Channel State Information

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Hossein Khaleghi Bizaki ◽  
Morteza Khaleghi Hojaghan ◽  
Seyyed Mohammad Razavizadeh
Keyword(s):  
Channel State Information ◽  
Communication Systems ◽  
Estimation Error ◽  
Multiple Input Multiple Output ◽  
Channel Estimation Error ◽  
Imperfect Channel State Information ◽  
Mimo Channels ◽  
Channel State ◽  
State Information ◽  
Input Multiple Output

This paper concentrates on the designing of a robust Tomlinson-Harashima Precoder (THP) over multiple-input multiple-output (MIMO) channels in wireless communication systems with assumption of imperfect channel state information (CSI) at the transmitter side. With the assumption that the covariance matrix of channel estimation error is available at the transmitter side, we design a THP that presents robustness against channel uncertainties. In the proposed robust THP, the transmit power is further minimized by using the Tilted constellation concept. This power minimization reduces the interchannel Interference (ICI) between subchannels and, furthermore, recovers some part of the THP's power loss. The bit error rate (BER) of the proposed system is further improved by using a power loading technique. Finally, the simulation results compare the performance of our proposed robust THP with a conventional MIMO-THP.

On the Capacity of MIMO Channels with Outdated Channel State Information

2011 ◽  
Vol 204-210 ◽  
pp. 2053-2056
Author(s):  
Ying Li ◽  
Yi Jun Zhu ◽  
Lan Ma ◽  
Yao Zhu
Keyword(s):  
Fading Channels ◽  
Channel State Information ◽  
Multiple Input Multiple Output ◽  
Ergodic Capacity ◽  
Mimo Channel ◽  
Wide Sense ◽  
Mimo Channels ◽  
Channel State ◽  
State Information ◽  
Input Multiple Output

A Multiple-input multiple-output (MIMO) time-varying flat fading channel is considered. The transmitter obtained the channel state information (CSI) relying on the reciprocity principle or by the feedback from the receiver. Thus, channel state information at the transmitter (CSIT) is outdated due to the delay between the estimation of the channel and the transmission of the data. In order to achieve the maximum channel capacity, the transmitter linearly precoded the signal before transmission based on the outdated CSIT. Under the assumptions of wide-sense stationary uncorrelated scattering Rayleigh fading channels and Jake’s model, the instantaneous mutual information and ergodic capacity is derived for MIMO channels with outdated CSIT. The information outage probability of MIMO channel with outdated CSIT is also presented.

Channel capacity analysis of non-orthogonal multiple access and massive multiple-input multiple-output wireless communication networks considering perfect and imperfect channel state information

2021 ◽  
pp. 154851292110001
Author(s):  
Ravi Shankar ◽  
Shovon Nandi ◽  
Ajay Rupani
Keyword(s):  
Multiple Access ◽  
Mimo System ◽  
Estimation Error ◽  
Multiple Input Multiple Output ◽  
Channel Estimation Error ◽  
Channel State ◽  
State Information ◽  
Multiple User ◽  
Multiple Input ◽  
Input Multiple Output

In this paper, we investigate the non-orthogonal multiple access (NOMA) and massive multiple-input multiple-output (M-MIMO) techniques and through simulation, and a comparison is given between the NOMA and orthogonal multiple access techniques. Integrating NOMA with M-MIMO is a very challenging task. In this paper, for a single-cell system, NOMA is integrated with a M-MIMO system for better spectral and energy efficiency. Investigation of the multiple user gain is the focus of this work because the multiple user gain supports simultaneous transmission of multiple users in the case of the M-MIMO system. In this way, the M-MIMO will provide a 100 times channel capacity increase, which results in very high data transmission rate. In the modern communication system, achieving multiple user gain is a very difficult task when channel estimation error is present. The performance of the orthogonal multiple access as well as NOMA system significantly reduced in the presence of channel estimation error. However, most of the current schemes do not work well with imperfect perfect channel state information conditions. Simulation results closely agree with the theoretical outcomes.

scholarly journals Transceiver Designs for MIMO Relaying Systems with Imperfect Channel State Information

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Bridget Durowaa Antwi-Boasiako ◽  
Changick Song ◽  
Kyoung-Jae Lee
Keyword(s):  
Channel State Information ◽  
Minimum Mean Square Error ◽  
Multiple Input Multiple Output ◽  
Imperfect Channel State Information ◽  
Amplify And Forward ◽  
Channel State ◽  
State Information ◽  
Closed Form Solutions ◽  
Relaying Systems ◽  
Transceiver Designs

We focus on imperfect channel state information (ICSI) in closed-loop multiple-input multiple-output (MIMO) amplify-and-forward (AF) relaying systems. First, near-optimal closed-form solutions for transceiver designs are provided for the source-to-relay-to-destination link with ICSI at all nodes. Next, considering a nonnegligible direct link with ICSI available only at the relay and destination and no CSI or ICSI at the source, near-optimal designs are proposed. The Wiener or minimum mean square error (MMSE) filter is employed at the destination to estimate the transmitted signal. The effect of CSI mismatch on the performance of the proposed scheme is then shown through simulations.

scholarly journals Coordinated Multicast Precoding for Multi-Cell Massive MIMO Transmission Exploiting Statistical Channel State Information

Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 338 ◽  
Author(s):  
Li You ◽  
Xu Chen ◽  
Wenjin Wang ◽  
Xiqi Gao
Keyword(s):  
Power Allocation ◽  
Channel State Information ◽  
Matrix Theory ◽  
Multiple Input Multiple Output ◽  
Base Stations ◽  
Channel State ◽  
State Information ◽  
Design Objective ◽  
Deterministic Equivalent ◽  
Input Multiple Output

This paper considers coordinated multi-cell multicast precoding for massive multiple-input-multiple-output transmission where only statistical channel state information of all user terminals (UTs) in the coordinated network is known at the base stations (BSs). We adopt the sum of the achievable ergodic multicast rate as the design objective. We first show the optimal closed-form multicast signalling directions of each BS, which simplifies the coordinated multicast precoding problem into a coordinated beam domain power allocation problem. Via invoking the minorization-maximization framework, we then propose an iterative power allocation algorithm with guaranteed convergence to a stationary point. In addition, we derive the deterministic equivalent of the design objective to further reduce the optimization complexity via invoking the large-dimensional random matrix theory. Numerical results demonstrate the performance gain of the proposed coordinated approach over the conventional uncoordinated approach, especially for cell-edge UTs.

Sign in / Sign up

Export Citation Format

Share Document