Implementation of Least Squares Channel Estimation on OFDM for Video Transmission Using GNU Radio-USRP
Lisallah- I Gede Puja Astawa- Faridatun Nadziroh- Budi Aswoyo- Anang Budikarso- Ida Anisah

Electronic Engineering Polytechnic Institute of Surabaya

Abstract

Orthogonal frequency division multiplexing (OFDM) is a transmission technique that utilizes a multicarrier transmission technique that uses a multicarrier, which divides the frequency spectrum into several subcarriers. At the same time, orthogonal signals are signals that are perpendicular to each other and overlapping with one another to strengthen the signal when transmitted. Each other strengthens the signal when transmitted through the frequency-selective fading channel. Channel estimation techniques are needed before the demodulation process to overcome distortion in the signal. To overcome the distortion in the signal caused by Frequency-Selective Fading and Time-Varying Fading. The Least Square (LS) channel estimation technique is a data-aided estimation technique. A set of pilots with predetermined values is inserted into the data. At the receiver side, this pilot value is retrieved, and the change in value is used to perform channel estimation. Then, the change in value is used to estimate the channel traveled by the signal and traveled by the signal. The set of pilot symbols with known values is inserted in the data of all OFDM symbols. In this research, the LS channel estimation method in the OFDM for the DVB-T system was implemented using a GNU-Radio-based USRP device to measure the performance of LS channel estimation. The performance of the LS method is obtained only up to a maximum distance of 8 meters with a delay of up to 9 seconds. Performance to get a Bit Error Rate (BER) value of around 0.284076 or 28% if the Signal to Noise Ratio (SNR) reaches around 24 dB.

Keywords: SISO OFDM, Channel Estimation, USRP, GNU Radio, Transmission Video

Topic: Digital Industry 4.0