Analysis the Performance of OFDM-MIMO Channel with Different Equalizers (original) (raw)
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MIMO-OFDM (Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing) system has been recognized as one of the most popular and competitive technique in a wireless environment nowadays. The performance is calculated in terms of Bit Error Rate (BER) versus the Signal to Noise Ratio (SNR). In this paper we discuss the BER performance of the MIMO-OFDM system with two different equalizers (ZF and MMSE) for various modulation techniques i.e. BPSK, QPSK, 16-QAM and 64-QAM using multipath fading channels i.e. AWGN (Additive White Gaussian Noise), Rayleigh and Rician channel. The multicarrier modulation is employed, which gives advantages like inter symbol interference (ISI) reduction, high data rate, higher reliability, and better performance in multipath fading. The simulation results show that, with MMSE and ZF equalizers, the BER performances is better in MMSE equalizer. Further we analyzed in different fading channels for various modulation techniques in both the equalizers.
Performance of MIMO-OFDM Transmission System on Wireless Networks
A detailed study of the performance of MIMO-OFDM transmission on WLAN physical layer specified in IEEE 802.11n, Wi-MAX (IEEE 802.16-2009) physical layer specified in 802.16 and LTE downlink physical channel (PDSCH) has been carried out using MATLAB Simulink. The WLAN and Wi-MAX system incorporates Convolution coding with 1/2 and 2⁄3 rated codes. The LTE incorporates Turbo coding with 1/2 and 2/3 rated codes. Orthogonal Frequency Division Multiple (OFDM) accesses uses adaptive modulation technique such as QPSK,16-QAM and 64-QAM, on the physical layer of WLAN, Wi-MAX and LTE and the concept of cyclic prefix that adds additional bits at the transmitter end. The Error Rate (BER) derived from simulation results show that the implementation with interleaved Convolution coding and Turbo coding under QPSK modulation technique is found to be highly efficient for WLAN, Wi-MAX and LTE wireless network system. The Implementation of MIMO–OFDM multiplexing on WLAN networks with QPSK modulation at BER ~10-3 dB, exhibits significant improvement in SNR ~ 2.75 dB, Wi-MAX network SNR ~ 3.75 dB and LTE network SNR ~7.55 dB. The improvement of SNR ~4.8 dB displayed between the MIMO-OFDM implementation on WLAN and LTE network can be attributed to the Turbo coding techniques adopted in LTE networks. Keywords-Multiple Input Multiple Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Phase Shift Keying (PSK), Quadrature Amplitude modulation (QAM), Bit Error Rate (BER), Signal to Noise Ratio (SNR), Line-of-Sight (LoS), Forward Error Correction (FEC), Wireless Local Area Network (WLAN), Worldwide interoperability for Microwave Access (Wi-MAX), Long Term Evaluation (LTE), Subscriber Station (SS), Base Station (BS).
Mimo Channel and Performance Analysis using OFDM System for Reduced Bit Error Rate
ABC Research Alert, 2015
Multiple-input Multiple-output (MIMO) systems use multiple antennas at the transmitter and receiver end, are a key technology to meet the growing demand for high data rate wireless systems. The aim of this thesis is to investigate MIMO system capacity with the aim of achieving optimum Bit Error Rate (BER) while increasing the system capacity using multicarrier delay diversity modulation (MDDM), proposed for fifth generation systems. In principle, the capacity of MIMO system can increase linearly with the number of antennas. Multiple antennas at the transmitter and receiver provide diversity in a fading environment. Furthermore, the research work in this thesis consists of different investigations of the basic principle of MIMO, Multiple-input Single-output (MISO) and Single-input Single-output (SISO) wireless communication systems with Space Time Codes (STC). A MISO systems and MIMO systems are schematized using MDDM which incorporated with Orthogonal Frequency Division Multiplexing (OFDM). OFDM is chosen over a single-carrier solution due to lower complexity of equalizers for high delay spread channels or high data rates. The design is implemented with binary Phase Shift Keying (BPSK) and simulated using MATLAB, which is examined in associated Additive White Gaussian Noise (AWGN) channel. The receiver-design is included with the maximal ratio combiner (MRC) receiving technique with perfect wisdom of channel state information (CSI). The theoretical performance is derived for AWGN channels and compared with the simulated results as well as compared between each system to another.
Wireless Communication: Trend and Technical Issues for MIMO-OFDM System
Advanced Trends in Wireless Communications, 2011
High-performance 4 th generation (4G) broadband wireless communication system can be enabled by the use of multiple antennas not only at transmitter but also at receiver ends. A multiple input multiple output (MIMO) system provides multiple independent transmission channels, thus, under certain conditions, leading to a channel capacity that increases linearly with the number of antennas. Orthogonal frequency division multiplexing (OFDM) is known as an effective technique for high data rate wireless mobile communication. By combining these two promising techniques, the MIMO and OFDM techniques, we can significantly increase data rate, which is justified by improving bit error rate (BER) performance. In this section, we briefly describe the concept of MIMO system. Through comparison with CDMA system, its key benefits are discussed. 1.1 Concept of MIMO system The idea of using multiple receive and multiple transmit antennas has emerged as one of the most significant technical breakthroughs in modern wireless communications. Theoretical studies and initial prototyping of these MIMO systems have shown order of magnitude spectral efficiency improvements in communications. As a result, MIMO is considered a key technology for improving the throughput of future wireless broadband data systems MIMO is the use of multiple antennas at both the transmitter and receiver to improve communication performance. It is one of several forms of smart antenna technology. MIMO technology has attracted attention in wireless communications, because it offers significant increases in data throughput and link range without requiring additional bandwidth or transmit power. This is achieved by higher spectral efficiency and link reliability or diversity (reduced fading). Because of these properties, MIMO is an important part of modern wireless communication standards such as IEEE 802.11n (Wifi), IEEE 802.16e (WiMAX), 3GPP Long Term Evolution (LTE), 3GPP HSPA+, and 4G systems to come. Radio communication using MIMO systems enables increased spectral efficiency for a given total transmit power by introducing additional spatial channels which can be made available by using space-time coding. In this section, we survey the environmental factors that affect MIMO performance. These factors include channel complexity, external interference, and channel estimation error. The multichannel term indicates that the www.intechopen.com Advanced Trends in Wireless Communications 206 receiver incorporates multiple antennas by using space-time-frequency adaptive processing. Single-input single-output (SISO) is the well-known wireless configuration, single-input multiple-output (SIMO) uses a single transmit antenna and multiple receive antennas, multiple-input single-output (MISO) has multiple transmit antennas and one receive antenna. And multiuser-MIMO (MU-MIMO) refers to a configuration that comprises a base station with multiple transmit/receive antennas interacting with multiple users, each with one or more antennas.
BER Performance Analysis of MIMO-OFDM Over Wireless Channel
2018
In this paper we propose a method for multiple input and multiple output orthogonal space time block coded orthogonal frequency division multiplexing system. This system is design to achieve high data rate without increasing the bandwidth of the channel and simultaneously increase in capacity range along with reliability in wireless communication system. Proposed method is used to maintain the orthogonality of wireless channel in MIMO-OFDM system with two transmit and arbitrary number of receive antennas. Orthogonality is most essential, so that the channels may remain un correlated, due to this condition, interference do not occurs between the data transmitted through wireless channel and also at receiver end ML and MMSE equalizer are used thus achieved performance improvement is compared .Which is evaluated through simulation.
Lecture Notes in Electrical Engineering, 2014
Combination of Multiple Input Multiple Output (MIMO) and Orthogonal Frequency Division Multiple Access (OFDMA) is implemented to offer a simple and high performance system as to increase channel capacity and serve high data rate. Even though the OFDMA concept is simple in its basic principle, but it suffers one of the most challenging issues, which is synchronization error that introduces the inter-symbol interference (ISI), thus degrades the signal performance. The goal of this paper is to provide a method to mitigate this ISI by employing the equalizers at the receiver end and using Space Time Block Codes (STFBC) to improve the Bit error rate (BER) performance and to achieve a maximum diversity order in MIMO-OFDMA by using simulation based on the platforms of MATLAB software As a result, the BER performance is improved when implementing equalizers at the receiver with STFBC outperforms the conventional system without equalizer with a maximum diversity order and an efficient bandwidth in the Mobile WiMAX system.
An Overview On Equalization Techniques for MIMO-OFDM Systems
2008
In this paper, we overview the fundamental techniques of MIMO OFDM equalization in channels where the maximum delay exceeds the length of the Guard Interval. The paper is divided to three main parts explaining frequency domain, time domain and turbo equalization, respectively. In frequency domain, per-tone equalization was chosen to be explained. Swapping the filtering operations of MIMO channel and sliding FFT, one can use the same equalization method of MIMO SC for each tone of MIMO OFDM. In time domain, we discuss techniques in which second order statistics of received signal is used. It is proven that this method is much more efficient than other time domain techniques such as channel shortening. In last chapter we will explain using of Turbo equalization in MIMO OFDM systems which is an iterative equalization and decoding technique for suppressing ISI.
Analysis of MIMO-OFDM using different Modulation Techniques
International Journal of Computer Applications, 2016
MIMO-OFDM system is fast growing new wireless broadband technology which has capability of high data rate transmission and advantages like inter carrier interference (ICI) reduction; high reliability; and better performance in multi-path fading. The major effect to be considered at receiver is fading effects which must be mitigated at receiver using equalization technique. In this paper we demonstrated the BER performance of the OFDM system with two different equalizers (ZF and MMSE). Proposed OFDM system is demonstrated using various modulation techniques that is BPSK, QPSK, 16-QAM and 64-QAM using multipath fading channels that is AWGN (Additive White Gaussian Noise) and Rayleigh channel.
IJERT-Bit Error Rate Performance of the OFDM MIMO System in Different Fading Channels
International Journal of Engineering Research and Technology (IJERT), 2016
https://www.ijert.org/bit-error-rate-performance-of-the-ofdm-mimo-system-in-different-fading-channels https://www.ijert.org/research/bit-error-rate-performance-of-the-ofdm-mimo-system-in-different-fading-channels-IJERTV5IS050325.pdf In this paper we observe the performance of MIMO-OFDM system in different channels such as Rayleigh channel, Rician channel and AWGN channel with respect to the bit error rate performance (BER). At the transmitter side we employ golden code encoding, a new type of space time coding with full rate and full diversity and at the receiver side we perform sphere decoding rather than ML decoding and MMSE equalizer for decreasing the complexity of decoding.
MIMO-OFDM : Foundation for Next-Generation Wireless Systems
IJRITCC
the conjunction of MIMO systems with OFDM has emerged as a promising technology in recent years. The use of multiple transmit and receive antennas forming MIMO-OFDM systems not only provide robustness against multipath fading impairments but also ensures significant increase in the rates over frequency selective channels. Furthermore this technology is now making possible to build high data rate communication systems with affordable receiver complexity. Because of these advancements, MIMO-OFDM has been widely adopted for different wireless standards all over the world and few names to mention are IEEE 802.11n (WLAN), IEEE 802.16e-2005(WiMAX), 3 rd Generation Partnership Project (3GPP) Long Term Evolution (LTE).