scholarly journals Experimental Evaluation of MIMO-OFDM System with Rateless Space-Time Block Code

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Ali H. Alqahtani ◽  
Khaled Humadi ◽  
Ahmed Iyanda Sulyman ◽  
Abdulhameed Alsanie
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Input Multiple Output ◽  
Block Code ◽  
Space Time ◽  
Ofdm System ◽  
Time Block ◽  
Space Time Block Code ◽  
Field Programmable ◽  
Input Multiple Output ◽  
Mimo Ofdm

Multiple-input multiple-output (MIMO) wireless technology in combination with orthogonal frequency-division multiplexing (MIMO-OFDM) is an attractive technique for next-generation wireless systems. However, the performance of wireless links is severely degraded due to various channel impairments which cause a decoding failure and lead to packet loss at the receiver. One technique to cope with this problem is the rateless space-time block code (RSTBC). This paper presents experimental results on the performance of a 2×2 MIMO-OFDM system with RSTBC as measured in a testbed implemented with field-programmable gate array (FPGA). The average bit error rate (BER) performance of the proposed scheme is evaluated experimentally, and the results agree closely with simulation and analytical upper bound. It has been shown that RSTBC can be implemented in real-world scenarios and guarantee the reliability of loss-prone wireless channels.

Combined Beamforming with Orthogonal Space Time Block Code for MIMO-OFDM with Simple Feedback

2016 ◽  
Vol 4 (3) ◽  
pp. 580
Author(s):  
Hala M. Abd Elkader ◽  
Gamal M. Abdel-Hamid ◽  
Adly Tag El-Dien ◽  
Asmaa A. Nassif
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Input Multiple Output ◽  
Block Code ◽  
Space Time ◽  
Ofdm System ◽  
Time Block ◽  
Downlink Transmission ◽  
Space Time Block Code ◽  
Orthogonal Space ◽  
Mimo Ofdm

<p>In this paper, we introduce a proposed scheme to enhance the performance of orthogonal space time block code (OSTBC) with four time slots and two antennas by combing OSTBC with random beamforming to can use it in the downlink transmission for a mobile system.  Multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) system has been recognized as one of the most promising techniques to achieve a good service and increase data rate in the next generation (4&amp;5G) broadband wireless communications. So, we apply Space time block code (STBC) for MIMO-OFDM system with linear decoding.  Also, we perform STBC with beamforming for MIMO-OFDM system to improve the performance of a system. Simulation results show that the beamforming improves bit error rate (BER) performance of OSTBC and STBC-OFDM for different types of modulation and diversity.</p>

scholarly journals Space Time Block Code Analysis for MIMO-OFDM System

2014 ◽  
Vol 100 (2) ◽  
pp. 1-7 ◽  
Author(s):  
Vinay Kumar ◽  
C. Ram Singla ◽  
Chirag Chirag
Keyword(s):  
Block Code ◽  
Space Time ◽  
Ofdm System ◽  
Time Block ◽  
Code Analysis ◽  
Space Time Block Code ◽  
Mimo Ofdm

Pilots Updating Channel Compensation Base on Underwater MIMO-OFDM

2012 ◽  
Vol 198-199 ◽  
pp. 1761-1767 ◽  
Author(s):  
Zong Xin Sun ◽  
Wei Wang ◽  
Yue Wang ◽  
Rehan Khan ◽  
Gang Qiao
Keyword(s):  
Spectral Efficiency ◽  
Hot Spot ◽  
Multiple Input Multiple Output ◽  
Block Code ◽  
Time Block ◽  
Improved Method ◽  
Space Time Block Code ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Mimo Ofdm

The communication rate is limited extremely by the confined bandwidth source of UWA (underwater acoustic) channel. MIMO (Multiple-input Multiple-output) techniques can drastically improve the spectral efficiency, and have been a new hot spot in UWA commutation. To estimate the UWA channel STBC (space-time block code) technique is adopted, and the improved method of channel estimating is also given. A designed of complex coding MIMO-OFDM is provided.The validity and the dependability of the scheme are verified by Monte Carlo simulations.

scholarly journals A Janus compatible software-defined underwater acoustic multiple-input multiple-output modem

2021 ◽  
Vol 17 (4) ◽  
pp. 155014772110106
Author(s):  
Surinder Singh ◽  
Mark Crispo ◽  
Jean-François Bousquet ◽  
Shadi Aljendi
Keyword(s):  
Transmission Rate ◽  
Multiple Input Multiple Output ◽  
Block Code ◽  
Continuous Phase ◽  
Space Time ◽  
Transmission Mode ◽  
Time Block ◽  
Space Time Block Code ◽  
Multiple Input ◽  
Input Multiple Output

This article describes the implementation of a multiple-input multiple-output acoustic communication link in shallow water conditions to enable a software-defined acoustic modem with a maximum transmission rate of 20 kbps in a 5-kHz bandwidth. The reliability improvement of a low-complexity Alamouti space–time block code is evaluated to improve the diversity in a high-rate transmission mode using single carrier modulation, as well as in a low-rate transmission mode relying on continuous-phase frequency-shift keying. Using measurements in realistic subsea conditions, the effect of the spatial channel correlation is demonstrated. It is found that for the space–time block code/continuous-phase frequency-shift keying, the spatial diversity is significantly degraded due to the high spatial correlation. In contrast, for the high-mode transmission rate, space–time block code with single carrier modulation offers a bit error rate improvement by a factor over hundred, in comparison to a single transmit element, demonstrating that the multiple-input multiple-output optimal code depends on the software-defined acoustic modem transmission mode.

scholarly journals Covert Communication in MIMO-OFDM System Using Pseudo Random Location of Fake Subcarriers

2016 ◽  
Vol 4 (1) ◽  
pp. 150-163 ◽  
Author(s):  
Rizky Pratama Hudhajanto ◽  
I Gede Puja Astawa ◽  
Amang Sudarsono
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Random Sequence ◽  
Multiple Input Multiple Output ◽  
Ofdm System ◽  
Transmission Scheme ◽  
Sensitive Data ◽  
Input Multiple Output ◽  
Mimo Ofdm ◽  
Random Location

Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) is the most used wireless transmission scheme in the world. However, its security is the interesting problem to discuss if we want to use this scheme to transmit a sensitive data, such as in the military and commercial communication systems. In this paper, we propose a new method to increase the security of MIMO-OFDM system using the change of location of fake subcarrier. The fake subcarriers’ location is generated per packet of data using Pseudo Random sequence generator. The simulation results show that the proposed scheme does not decrease the performance of conventional MIMO-OFDM. The attacker or eavesdropper gets worse Bit Error Rate (BER) than the legal receiver compared to the conventional MIMO-OFDM system.

scholarly journals Channel capacity and performance evaluation of precoded MIMO-OFDM system with large-size constellation

2019 ◽  
Vol 9 (6) ◽  
pp. 5024
Author(s):  
Hussein A. Leftah ◽  
Huda N. Alminshid
Keyword(s):  
Fading Channels ◽  
Channel Capacity ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Input Multiple Output ◽  
Ofdm System ◽  
Large Size ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Mimo Ofdm ◽  
And Performance

<p>Multiple input-multiple output (MIMO) is a multipath diversity exploring approach which is emerged with orthogonal frequency division multiplexing (OFDM) to produce MIMO-OFDM that is widely used in wireless communications. This paper presents a discrete Hart-ley transform (DHT) precoded MIMO-OFDM system over multipath frequency-selective fading channel with large-size quadrature amplitude modulation (16-QAM, 64-QAM and 256-QAM). A mathematical models for the BER and channel capacity over mutlipath fading channels are also derived in this paper. Average Bit-error-rate (BER) and channel capacity of the presented system is considered and compared with that of the traditional MIMO-OFDM. Simulation results shows that the transmission performance and channel capacity of the proposed schemes is better than that of the traditional MIMO-OFDM without a pre-coder.</p>

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