Interference Analysis for the Co-existence of DTTV and LTE Systems in the Digital Dividend (700MHz) band in Nigeria

Abstract

This paper seeks to present the coexistence simulation of Digital Terrestrial Television (DTTV) and Long Term Evolution (LTE) Systems in Nigeria using Spectrum Engineering Advanced Monte Carlo Analysis Tool (SEAMCAT) software. This research work investigated the interference Probability of Channel 17 (490MHz) and Channel 51 (693MHz) when DTTV and LTE systems coexist within the proposed Digital Dividend (700MHz) band. The study focused on cellular system LTE Down-link (DL) signal from the nearest cell site interfering with the Digital Terrestrial Television (DTTV) fixed outdoor receiving antenna in Port Harcourt, Nigeria. The simulation data used were obtained from Star Time transmitting Station in Port Harcourt and Smile LTE 4G Communication LTD Base Station (eNBs) Network also in Port Harcourt. The Star time transmitting station was adopted as the Victim Link Transmitter (VLT) while the Smile LTE 4G Communication was taken as the Interfering Link Transmitter (ILT) respectively. From the Monte-Carlo simulation result, the probability of interference for channels 17 and Channel 51 are 0.783 and 0.84 when the DTTV receiver (VLR) and LTE Base station (ILT) are separated by a distance of 0.5Km while their probability of interference are 0.095 and 0.138 when VLR and ILT are separated by a distance of 5Km respectively. It was observed from the simulation result that the probability of interference is a function of the separation distance between Smile 4G LTE base stations (ILT) and Star time Television Receivers (VLR). It was observed from the analysis that as the separation distance between DTTV and LTE systems decreases, the interference probability of the two systems will increase and the value will tend to infinity. It was established that DTTV channel 51 suffer more interference when compared with DTTV channel 17 for the same separation distance. The difference in the probability of interference results is due to the closeness of channel 51 to the proposed LTE frequency spectrum in the proposed digital dividend band. The results of the study show that when LTE and Digital terrestrial television services operate in the Digital Dividend bands, LTE transmitters can cause harmful Interference to the television reception.