Performance Improvement Using Spline LS and MMSE DFT Channel Estimation Technique in MIMO OFDM Using Block-Type Pilot Structure

Abstract

Multiple input multiple output (MIMO) is a very important and prominent key technology in wireless system which is extensively used in 4G systems. However, accurate channel estimation poses a challenge in reducing error rate in MIMO-LTE system. For choosing a correct estimate for the MIMO-LTE system, there are many aspects for implementation which include time variation, computation, and performance of the channel like Rayleigh or Rican. The least square (LS) and minimum mean square error (MMSE) are the two well-known techniques for estimating the channel. In this paper, we used these techniques along with linear and cubic spline interpolation techniques. In this work, Discrete Fourier Transform (DFT)-based channel estimation technique is presented for improvement in the performance of MMSE and LS estimation techniques using block-type pilot arrangement. Signal-to-noise ratio and BER performance of all channel estimation schemes have been evaluated with modulation techniques, MQAM and MPSK over Rayleigh and AWGN noise channels. This paper presents that DFT channel estimation scheme improves the performance of LS and MMSE channel estimation via noise reduction outside channel delay for 2 × 2 MIMO system.