scholarly journals Asymmetric Turbo Code for Coded-Cooperative Wireless Communication Based on Matched Interleaver with Channel Estimation and Multi-Receive Antennas at the Destination

2017 ◽  
Vol 26 (3) ◽  
pp. 878-889 ◽  
Author(s):  
S. Mughal ◽  
F. F. Yang ◽  
S. Ejaz ◽  
S. H. Ahmed ◽  
R. Umar
Keyword(s):  
Wireless Communication ◽  
Channel Estimation ◽  
Turbo Code

An Adaptive Phase Tracking Scheme of OFDM Wireless Communication System

2013 ◽  
Vol 336-338 ◽  
pp. 1798-1803
Author(s):  
Qian Du ◽  
Wen Wu Xie
Keyword(s):  
Kalman Filter ◽  
Wireless Communication ◽  
Channel Estimation ◽  
Error Estimation ◽  
Communication System ◽  
Phase Error ◽  
Basic Structure ◽  
Adaptive Kalman Filter ◽  
Phase Tracking ◽  
New Phase

This paper proposes a new phase tracking algorithm for the 802.11a system. Since this system illuminates the basic structure of 802.11a system, and introduces the OFDM frame generation principle based the transmitter, phase error estimation and channel estimation. On the basis of this, this paper presents a phase tracking scheme based on adaptive Kalman filter, and then simulates the process based on 802.11a system. The result indicates that the BER has been improved because of this adaptive phase tracking scheme.

scholarly journals A high throughput architecture for a low complexity soft-output demapping algorithm

2015 ◽  
Vol 13 ◽  
pp. 73-80 ◽  
Author(s):  
I. Ali ◽  
U. Wasenmüller ◽  
N. Wehn
Keyword(s):  
Wireless Communication ◽  
High Throughput ◽  
Turbo Code ◽  
Low Complexity ◽  
Implementation Cost ◽  
Qam Modulation ◽  
Iterative Systems ◽  
Very High ◽  
Complexity Algorithm ◽  
Hardware Performance

Abstract. Iterative channel decoders such as Turbo-Code and LDPC decoders show exceptional performance and therefore they are a part of many wireless communication receivers nowadays. These decoders require a soft input, i.e., the logarithmic likelihood ratio (LLR) of the received bits with a typical quantization of 4 to 6 bits. For computing the LLR values from a received complex symbol, a soft demapper is employed in the receiver. The implementation cost of traditional soft-output demapping methods is relatively large in high order modulation systems, and therefore low complexity demapping algorithms are indispensable in low power receivers. In the presence of multiple wireless communication standards where each standard defines multiple modulation schemes, there is a need to have an efficient demapper architecture covering all the flexibility requirements of these standards. Another challenge associated with hardware implementation of the demapper is to achieve a very high throughput in double iterative systems, for instance, MIMO and Code-Aided Synchronization. In this paper, we present a comprehensive communication and hardware performance evaluation of low complexity soft-output demapping algorithms to select the best algorithm for implementation. The main goal of this work is to design a high throughput, flexible, and area efficient architecture. We describe architectures to execute the investigated algorithms. We implement these architectures on a FPGA device to evaluate their hardware performance. The work has resulted in a hardware architecture based on the figured out best low complexity algorithm delivering a high throughput of 166 Msymbols/second for Gray mapped 16-QAM modulation on Virtex-5. This efficient architecture occupies only 127 slice registers, 248 slice LUTs and 2 DSP48Es.

scholarly journals A Novel Channel Estimation Technique in MIMO-OFDM Mobile Communication Systems

2020 ◽  
Vol 9 (02) ◽  
pp. 08-14
Author(s):  
Dr. V. Arthi
Keyword(s):  
Wireless Communication ◽  
Channel Estimation ◽  
Channel State Information ◽  
Communication Systems ◽  
Broad Band ◽  
Wireless Communication Systems ◽  
Channel State ◽  
Multimedia Services ◽  
State Information ◽  
Dynamic Estimation

4G Wireless communication systems have the inherent capability to foster the multimedia services in terms of bandwidth and data rate. These systems have very high integrity compared to the conventional wireless communication systems. It can fully support extended multimedia services with High Definition quality, audio and video files. Wireless internet and other broad band services provided superior quality signal transmission and reception. The degree of freedom enjoyed by the technology in terms of scalability and reliability is highly commendable. Any basic wireless transmitter sends information by varying the phase of the signal. In the receiver end, the desired signal can be decoded by appropriate decoding algorithm. The degradation occurs at the conventional receivers due to lack of Channel State Information. The efficiency of 4G system purely relies on the performance of receiver and is purely dependent on the synchronization of estimated instantaneous channel. In any wireless terminal, channel state information provides the in and around status of the channel. It provides the following parameters of the propagating signal (ie) Scattering, Fading and Attenuation. The dynamic estimation of channel state information can be obtained through Enhanced Least Squares channel estimation algorithm. It is based on Multi Carrier Filter Bank Transmission system. This  kind of dynamic estimation can be done with a set of well-known sequence of  coded unique bits .For a transmitter the information propagation is initiated in the form of frame bursts. It enhances the throughput of the system to the required level.

scholarly journals Research of the Channel Estimation in Wireless Communication Systems

2019 ◽  
Vol 25 ◽  
pp. 01002 ◽  
Author(s):  
Lili Zhao ◽  
Peng Zhang ◽  
Qicai Dong ◽  
Xiangyang Huang ◽  
Jianhua Zhao ◽  
...  
Keyword(s):  
Wireless Communication ◽  
Channel Estimation ◽  
Communication Technology ◽  
Communication Systems ◽  
Communication Channel ◽  
Data Transfer ◽  
Estimation Methods ◽  
Wireless Communication Systems ◽  
Data Transfer Rate

Wireless communication technology has been developed rapidly after entering the 21st century. Data transfer rate increased significantly as well as the bandwidth became wider and wider from 2G to 4G in wireless communication systems. Channel estimation is an import part of any communication systems; its accuracy determines the quality of the whole communication. Channel estimation methods of typical wireless communication systems such as UWB, 2G and 3G have been researched.

Sign in / Sign up

Export Citation Format

Share Document