SPACE TIME CODING TECHNIQUE FOR WIRELESS COMMUNICATION USING MIMO SYSTEM FOR CHANNEL ESTIMATION

摘要

The randomness of the communication channel leads to random fluctuation in the received signal. This fluctuation known as fading. Fading is a major problem in wireless communication because of this fading we cannot get exact signal at the receiver side. The wireless channel is non stationary and noisy due to fading and interference. The transmitting signal in wireless channel suffers from two main categories, propagation effects which are large scale fading and small scale fading effects. To improve the signal performance diversity technique is being used. Diversity conveying information through multiple independent random fades. Diversity technique uses multiple-input and multiple output (MIMO) concepts to overcome the problem of fading and interference in a wireless channel. Space time coding arises from a technique known as diversity. MIMO system enables increased spectral efficiency. This paper presents the progress made towards determining the capacity and diversity benefits of multiple antennas under different assumptions about the underlying channel. Simulations suggest that the resulting codes allow for effective high-rate data transmissions in multiple antenna communication systems. Rayleigh channel model and evaluate its performance in term of BER. Finally, the simulation results will be used to analyze and compare their performance. Through work, it is investigated and demonstrated that significant gains can be achieved by increasing the number of transmit antennas. We provided a space time codes for transmission using multiple transmit antennas. The encoding and decoding of these codes have low complexity. It is essential to observe that the two, three, and four transmit antennas schemes shows no error at any value of SNR.The research will be conducted in MATLAB environment.