ABSTRAKSI: Dalam propagasi mobile wireless, fading merupakan karakteristik utama. Terdapat dua macam fading yaitu small scale fading dan large scale fading. Smale scale fading merupakan fluktuasi yang cepat dari kuat sinyal yang diterima oleh receiver pada jarak dan waktu yang sangat kecil. Hal ini disebabkan oleh pantulan multipath yang dapat menyebabkan berbagai permasalahan seperti multipath fading, delay spread, dan doppler shift. Large scale fading merupakan model propagasi yang memperkirakan data tentang kuat sinyal untuk jarak transmitter dan receiver yang bervariasi yang berguna untuk memperkirakan daerah cakupan radio transmitter.
Pada penelitian ini, dilakukan simulasi untuk melihat pengaruh perbedaan jarak dan kecepatan terhadap kualitas sinyal terima Mobile Station (MS) pada teknologi Long Term Evolution (LTE). Analisis untuk jarak 0,5 sampai 5 km dan pada kecepatan 3 km/jam, 15 km/jam, 50 km/jam , dan 120 km/jam.
Untuk simulasi perbedaan kecepatan user, saat kecepatan user rendah (3 km/jam) didapat SNR sebesar 36,5 dB menggunakan modulasi QAM-64 untuk target BER 10-4, sedangkan saat kecepatan tinggi 120 km/jam, target BER 10-4 tidak terpenuhi, hal ini dikarenakan terdapat pengaruh dari efek Doppler pada kanal yang menyebabkan penurunan kualitas transmisi pada LTE. Dari simulasi untuk perbedaan jarak user didapatkan level sinyal terima LTE paling baik saat jarak user sejauh 500 m dengan RSL -73,165 dan untuk jarak user 5 km, level sinyal melemah dengan RSL -111.165 dBm.
Kata Kunci : Long Term Evolution, Walfish-ikegami, Bit Error Rate, Signal toABSTRACT: In mobile wireless propagation, fading is a major characteristic. There are two types of fading, such as small scale fading and large scale fading. Smale scale fading is the rapid fluctuation of the signal strength received by the receiver at a distance and a very small time. This is due to multipath reflections that can cause various problems such as multipath fading, delay spread and doppler shift. Large scale fading is propagation models that estimate data about signal’s strong to the transmitter and receiver range varied useful for estimating the coverage area of the radio transmitter.
In this thesis the authors performed simulations to see the effect of differences in distance and speed of the received signal quality Mobile Station (MS) in technology Long Term Evolution (LTE). Analysis for a distance of 0,5 km to 5 km and at a speed of 3 kmph, 15 kmph, 50 kmph and 120 kmph.
To simulate the difference of user speed, when the user speeds low (3 kmph) at 36,5 dB SNR obtained using QAM-64 modulation for the target BER 10-4, while at high speeds at 120 kmph, the target BER of 10-4 are not met, this is because there are the influences of the Doppler effect in canal which causes a decrease in transmission quality in LTE. The simulation results for the difference of user distance show in signal level received at the LTE user best when the distance as far as 500 m with RSL - 73,165 user and to distance 5000 m, the signal level down to the RSL -111,165 dBm.
Keyword: Long Term Evolution, Walfisch Ikegami, Pathloss, Doppler Shift, Bit Error