Design and Performance Analysis of MIMO-DSSS System for 2.4 GHz ISM Band Wi-Fi Applications Using Microstrip Antennas

In this paper, compact antenna has been designed and implemented in a 2X2 Multiple-Input Multiple-Output (MIMO) system. The antennas are compact double-sided printed microstrip patch antennas and fed by a microstrip line designed for a frequency of 2.4 GHz used for industrial, scientific and medical (ISM) band applications. Polarization diversity of the two antennas is used to construct independent and uncorrelated signals on each antenna. The antennas are designed on CST Microwave studio simulation software with return loss less than -10dB, and the two antennas are combined as a single system forming a MIMO array of two antennas, Further, using the results from CST, MIMO-DSSS system has been implemented and a performance analysis of this system is done on MATLAB software. The performance of this system is studied using BPSK modulation and finally bit error rate is obtained. The paper details the implementation of the digital communication system along with the simulated and measured results. The system is designed for 802.11n Wi-Fi family of standards that has an operation frequency of 2.4 GHz but with MIMO system that offers an increased data rate.