Abstract

AbstractThe mobile Worldwide Interoperability for Microwave Access (WiMAX) is based on IEEE

802.16 standard and is used for wireless Metropolitan Area Network (MAN). The IEEE 802.16

standard supports high data rate and high capacity in mobile Broadband Wireless Access

(BWA). The inclusion of Multiple Input Multiple Output (MIMO) in mobile WiMAX system

provides a robust platform for space, time and frequency selective fading conditions and

increases both data rate and system performance.

The MIMO-mobile WiMAX using Space Time Block Codes (STBC) technique is developed for

different modulation schemes (BPSK,QPSK,QAM) with the consideration of 1/2, 3/4 code rate

to determine and analyse Bit Error Rate (BER) performance under AWGN channel. The

simulation of MIMO-mobile WiMAX model is done by using MATLAB.

Various combining techniques are used along with diversity techniques. These techniques are

used in order in order to improve the intensity and strength of the signal at the receiver. These

techniques are simple and have good system performance. Basically, three combining technique

are in common use. These are the Maximum Ratio Combining technique (MRC), Equal Gain

Combining technique (EGC) and the Selective combining technique. Out of these, MRC has the

best system performance.

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NOTATIONSBWA - Broadband Wireless Access

Wi-MAX - Wireless Interoperability for Microwave Access

MIMO - Multi Input Multi Output

STBC - Space Time Block Coding

BER - Bit Error Rate

SNR - Signal to Noise Ratio

QPSK - Quadrature Phase Shift Keying

QAM - Quadrature Amplitude Modulation

AWGN - Additive White Gaussian Noise

MRC - Maximum Ratio Combining

LOS - Line of Sight

NLOS - Non Line Of Sight

SISO - Single Input Single Output

MMSE - Minimum Mean Square Error

MLSE - Maximum Likehood Sequence Estimator

EGC - Equal Gain Combining

MBS - Multicaste Broadcast Service

DSL - Digital Subscriber Line

OFDM - Orthogonal Frequency Division Multiplexing

SER - Symbol Error Rate

r -- Decoder Matrix

n -- Noise Matrix

h -- Encoder Matrix

h* -- Conjugate of Variable of Encoder Matrix

S- -- Alamouti Encoder Matrix

h 1(t) & h 2(t) -- Fading Coefficients

s1 & s2 – Modulated Symbols Alamouti Encoded Matrix

t -- Symbol Period

g -- Co-phase Signal

N -- No. of Transmit Antenna

M -- No. of Received Antenna

LIST OF FIGURES

FIG. NO. NAME OF FIGURE PAGE

NO.

Fig.1 Basic Communication System

Fig.2 Application of Wi-max

Fig.3 Block Diagram of Transmitter and Receiver MIMO Wi-max

Fig.4 Alamouti Space Time Encoder

Fig.5 Alamouti Space Time Decoder

Fig.6 Maximum Ratio Combining

Fig.5.1 BER performance with QPSK modulation under different Channels

Fig.5.2 BER performance with different modulation schemes under AWGN

channel

Fig.5.3 BER performance with different modulation schemes under Rayleigh

channel

Fig.5.4 BER performance for different modulation scheme under

Rician channel

Fig.5.5 BER performance for different diversity techniques for QPSK

Fig.5.6.1 BER Performance & Comparison of STBC(3x4), Alamouti(2x1),

Alamouti(2x2) in AWGN Channel with QPSK


Alamouti(2x2) in AWGN Channel with 8-PSK


Alamouti(2x2) in AWGN Channel with 16-QAM


Alamouti(2x2) in AWGN Channel with 64-QAM

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Alamouti(2x2) in Rayleigh Channel with QPSK


Alamouti(2x2) in Rayleigh Channel with 8-PSK


Alamouti(2x2) in Rayleigh Channel with 16-QAM


Alamouti(2x2) in Rayleigh Channel with 64-QAM


Alamouti(2x2) in Rician Channel with QPSK


Alamouti(2x2) in Rician Channel with 8-PSK


Alamouti(2x2) in Rician Channel with 16-QAM


Alamouti(2x2) in Rician Channel with 64-QAM

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Abstract

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