scholarly journals Concatenated RS-Convolutional Codes for Cooperative Wireless Communication

2013 ◽  
Vol 7 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Yahya Mohammed Hameed Al-Moliki ◽  
Kamarul Ariffin Bin Noordin ◽  
MHD Nour Hindia ◽  
Mohd Fadzli Bin Mohd Salleh
Keyword(s):  
Wireless Communication ◽  
Mimo System ◽  
Convolutional Codes ◽  
Ieee 802.16E ◽  
Decode And Forward ◽  
Video Broadcasting ◽  
Rs Codes ◽  
Single Antenna ◽  
Channel Codes ◽  
Coded Cooperation

In the last few years, several works have investigated the performance of cooperative wireless systems with various types of channel codes such as Low Density Parity Check (LDPC), Turbo, CRC, convolutional and recently Reed Solomon (RS) codes. These cooperative schemes give power to single antenna mobiles to originate virtual multiple antennas transmitter, MIMO system, by sharing their antennas so that diversity gain is achieved. The most common cooperative schemes are decode and forward (DF) and coded cooperation (CC). Concatenated Reed Solomon and convolutional codes have been used by several wireless communication standards like digital video broadcasting (DVB) standards and IEEE 802.16e WiMAX standard. In this paper, we develop two different coded cooperation schemes and apply them to the mandatory structure of physical layer specifications of IEEE 802.16e WiMAX. The results attained for both coded cooperation schemes present magnificent diversity gains over non-cooperative scheme.

scholarly journals A Design of MIMO Prototype in C-Band Frequency for Future Wireless Communications

2020 ◽  
Vol 9 (1) ◽  
pp. 78-84
Author(s):  
N. M. K. Al-Ani ◽  
O. A. S. Al-Ani ◽  
M. F. Mosleh ◽  
R. A. Abd-Alhameed
Keyword(s):  
Wireless Communication ◽  
Mutual Coupling ◽  
Mimo System ◽  
Circular Ring ◽  
Band Frequency ◽  
Wireless Applications ◽  
Single Antenna ◽  
Measurement Results ◽  
The Impact ◽  
System Prototype

The main challenges of MIMO design for future wireless communication is size reduction which leads to more mutual coupling. This paper deals with this problem in order to mitigate the impact of mutual coupling by proposing four elements MIMO prototype each one having a dual polarized patch rectangular microstrips. The idea is to insert annular rectangular opened one ribs in front of each microstrip and in corresponding to circular ring slot etched has etched in the ground. The advantage of such slot is to obtain regular radiation pattern distributed around device body. The four elements with eight ports are incorporated on 67×139 mm2 PCB with FR-4 dielectric layer. The single antenna is simulated CST.STUDIO 2019 resulting an operated frequency of 6.23 GHz with a band of 850 MHz (5.81-6.66) GHz at -10 dB. The fabrication MIMO system prototype is tested to show its measurement results which are match the simulated results. All results confirm of that proposed MIMO prototype which is operated at C-band frequency which is very important for future wireless applications.

scholarly journals Implementation of a Zero-Forcing Precoding Algorithm Combined with Adaptive Beamforming Based on WiMAX System

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Hyunwook Yang ◽  
Seungwon Choi
Keyword(s):  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Experimental System ◽  
Multiple Access Interference ◽  
Adaptive Beamforming ◽  
Base Station ◽  
Zero Forcing ◽  
Single Antenna ◽  
Input Multiple Output ◽  
Wimax System

We propose a novel precoding algorithm that is a zero-forcing (ZF) method combined with adaptive beamforming in the Worldwide Interoperability for Microwave Access (WiMAX) system. In a Multiuser Multiple-Input Multiple-Output (MU-MIMO) system, ZF is used to eliminate the Multiple Access Interference (MAI) in order to allow several users to share a common resource. The adaptive beamforming algorithm is used to achieve the desired SNR gain. The experimental system consists of a WiMAX base station that has 2 MIMO elements, each of which is composed of three-array antennas and two mobile terminals, each of which has a single antenna. Through computer simulations, we verified that the proposed method outperforms the conventional ZF method by at least 2.4 dB when the BER is 0.1%, or 1.7 dB when the FER is 1%, in terms of the SNR. Through a hardware implementation of the proposed method, we verified the feasibility of the proposed method for realizing a practical WiMAX base station to utilize the channel resources as efficiently as possible.

scholarly journals Three-Dimensional MIMO Channel Model with High-Mobility Wireless Communication Systems Using Leaky Coaxial Cable in Rectangular Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Kai Zhang ◽  
Fangqi Zhang ◽  
Guoxin Zheng ◽  
Lei Cang
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Channel Model ◽  
Mimo System ◽  
Three Dimensional ◽  
High Mobility ◽  
Coaxial Cable ◽  
Mimo Channel ◽  
Wireless Communication Systems ◽  
Rectangular Tunnel

With the rapid development of high-mobility wireless communication systems, e.g., high-speed train (HST) and metro wireless communication systems, more and more attention has been paid to the wireless communication technology in tunnel-like scenarios. In this paper, we propose a three-dimensional (3D) nonstationary multiple-input multiple-output (MIMO) channel model with high-mobility wireless communication systems using leaky coaxial cable (LCX) inside a rectangular tunnel over the 1.8 GHz band. Taking into account single-bounce scattering under line-of-sight (LoS) and non-line-of-sight (NLoS) propagations condition, the analytical expressions of the channel impulse response (CIR) and temporal correlation function (T-CF) are derived. In the proposed channel model, it is assumed that a large number of scatterers are randomly distributed on the sidewall of the tunnel and the roof of the tunnel. We analyze the impact of various model parameters, including LCX spacing, time separation, movement velocity of Rx, and K-factor, on the T-CF of the MIMO channel model. For HST, the results of some further studies on the maximum speed of 360 km/h are given. By comparing the T-CF between the dipole MIMO system and the LCX-MIMO system, we can see that the performance of the LCX-MIMO system is better than that of the dipole MIMO system.

Performance Improvement of MU-MIMO System by Optimizing the K-Factor for the K-Mean User Grouping Algorithm

2016 ◽  
Vol 5 (3) ◽  
pp. 89
Author(s):  
Ankush Kansal ◽  
Pawandeep Singh
Keyword(s):  
Mimo System ◽  
Access Point ◽  
Base Station ◽  
Optimum Number ◽  
Multiuser Mimo ◽  
User Grouping ◽  
Single Antenna ◽  
User Groups ◽  
Sum Rate ◽  
Grouping Algorithm

<p>In this paper, downlink multiuser-MIMO system with large number of transmitting antennas at the base station and R user terminals each having single antenna is considered. According to this design, an access point communicates with large number of users in the Rayleigh fading scenario. Due to large number of users, it becomes difficult to accommodate all of them in the system simultaneously. So, a user grouping technique known as K-mean clustering is used, such that a group of users with similar conditions at that particular time are served together. While making groups, the interference is surely reduced but the number of users being served at a time also reduces. So, it is necessary to make out the balance such that the performance of the system is maintained while accommodating maximum number of users. So, optimum number of user groups needs to be formed. The results show that when groups are increased from two till four sum rate increases but when five groups are made the sum rate decreases to a point but, is still higher than two groups.</p><p> </p>

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