International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 05 | May-2017
p-ISSN: 2395-0072
www.irjet.net
Performance Comparison of Bit Error Rate in SISO and MIMO Using VBLAST-STBC System Swarnajit Mukherjee1, Amlan Datta2 1Student,
Master of Technology, School of Electronics Engineering, KIIT University, Bhubaneswar, Odisha, India Dean, School of Electronics Engineering, KIIT University, Bhubaneswar, Odisha, India ---------------------------------------------------------------------***--------------------------------------------------------------------2Associate
Abstract - This paper presents a detailed analysis of the
decrease the fading which causes due to multiple propagation of signal. The propagation which is based on Line Of Sight (LOS), the beam forming results in a one directional pattern over a well synchronized manner. However regular beams do not have a good correlation with the networks related to cellular and mobile and they only depend on multiple signals being propagated over different channels. If we consider that the receiver has more than one antennas then the beam forming of transmitting side cannot increase the level of signal to reach to the individual receiving antennas simultaneously. So here pre-coding plays a vital role which uses more than one streams that enhances the signal level.
working of Vertical Bell Laboratories Layered Space Time (VBLAST) coding technique by the support of SISO and MIMO systems. In this paper we compared the results of Bit Error Rate (BER) values in SISO and MIMO system by the help of Zero Forcing (ZF) equalizer. A single step demodulation and decoding operation may suffer a great downfall in performance of the system. VBLAST space time coding algorithm is used as an iterative way for demodulation and decoding operation so that efficiency of the system can be improved. A mathematical model is also made to represent the working of Zero Forcing detector and receiver model Key Words: Multiple Input Multiple Output (MIMO), Single Input Single Output (SISO), VBLAST, Zero Forcing equalizer
If a signal is having high data rate, then in case of spatial multiplexing the high data rate signal is divided into signals with smaller data rates and then it is given as input to the transmitter and multiple antennas in the transmitter side transmits these signals with small data rates over a constant frequency channel. If these signals with smaller data rate reach at the receiver with different signal characteristics then the only way the receiver can separate these signal if the receiver is having Channel State Information (CSI). Spatial multiplexing is a very efficient method to increase the capacity of a channel even if the system works on high Signal to Noise Ratio (SNR).
2. INTRODUCTION In the field of radio technology, we use Multiple Input Multiple output (MIMO) as a method of increasing or multiplying the capacity of a system having radio links by using more than one antennas in both transmitter and receiver side so that radio signals can reach to more than one antenna and hence multiple propagation of signal can take place. Since more than one signal can be sent and received by the help of Multiple Input Multiple Output (MIMO) technology, so it has become an important part in the area of wireless communication. Single Input Single Output are having less complexity as compared to MIMO technology. An institute which makes standards for technologies related to multiple antennas are, IEEE 802.11n for Wi Fi and 802.11 ac for (Wi Fi) Wireless Fidelity, High Speed Packet Access (HSPA) and 3rd Generation (3G). Since it has only one antenna in transmitting side and one antenna on receiving side, so interaction between the transmitter and receiver is very low.
Diversity coding is a method in which single data stream is being transmitted but the main difference with other techniques is, we apply Space Time Block Code (STBC) over the data stream. Diversity coding increases the fading diversity. Channel knowledge, beam forming and array gain is not present in diversity coding. The main advantage of using Space Time Block Coding (STBC) is it forms multiple versions of receiving signal which increases the reliability of the data. Space Time Block Code (STBC) is orthogonal in nature that means any vector or any representation of any part of the signal will be orthogonal in nature
Pre-coding is a beam forming technique which uses multiple stream of parallel data. All the processing related to spatial diversity is done at the transmitter end of the system. If the beam forming is single data stream in nature, having a corresponding phase and gain then the signal power will increase at the receiver end of pre-coding Multiple Input Multiple Output (MIMO) system. The main aim of having a beam forming is to increase the gain of a signal. The gain of signal can be increased by adding up all the signals that are being emitted from different antennas and finally this will
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2. LITERATURE SURVEY Branka Vucetic [1] et al., the author of this paper has described how the capacity of wireless communication decreases and could not meet the demands of data transmission. The decrease in capacity is due to low data rates, low spectral efficiency and degradation in quality of service. This paper shows how space time coding can be used to avoid fading in wireless communication. Space time codes are highly efficient in context to bandwidth which helps in
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