Mimo Capacity

International Journal of Engineering Research & Technology (IJERT)

ISSN: 2278-0181

Vol. 2 Issue 8, August - 2013

Performance Analysis Of Space Time Block Codes Over Rayleigh Fading

Channel

Mandeep

Department of Electronics and

Communication, GJUS&T, Hisar (Haryana)

Deepak Kedia

Department of Electronics and

Communication, GJUS&T, Hisar (Haryana)

Abstract

j=1,2,3…,m) is constant as the quasi-static Reyleigh

fading channel is assumed.

To overcome the effect of multi-path fading of the

channel and to achieve full diversity, the multiple

antennas seems to be an efficient solution. STBC

provides a new concept of transmission over Rayleigh

channel using multiple transmit and receive antenna.

This paper presents a detailed study of STBC scheme

which includes the Alamouti’s STBC for two

transmitting antennas as well as orthogonal space time

codes (OSTBC) for three and four transmitting

antennas. Bit Error Rate (BER) performance is

simulated and analyzed for different constellation

schemes as BPSK, QPSK ,8-PSK and 16-QAM using

MATLAB.

At time t the received signal , at antenna j is given by

Where are independent noise samples of zero-mean

complex Gaussian random variables. For all code words

1 2

1 2

= 1 1 … 1 2 2 … . 2 … … . 1 2 … … the receiver

computes the decision metric

Consider a wireless communication system with n

transmitting and m receiving antennas. At each time slot

t, signals , i=1,2,3………,n are transmitted from n

transmit antennas. Assume the channel to be flat fading

and path gains from transmitter antenna i to receiver

antenna j is defined to be ℎ , . The path gains are

modeled as samples of independent complex Gaussian

random variable with variance 0.5 per real dimension

[2]. The channel coefficient ℎ , (i=1,2,3…..,n;

IJERTV2IS80091

2

ℎ ,

−

(2)

=1

=1 =1

in favor of the codeword that minimizes this sum and

completes the ML (Maximum...