| Summary: | 碩士 === 高苑科技大學 === 電機工程研究所 === 100 === In this paper , we compare the performances of the modulation error ratio (MER) between Digital Terrestrial Multimedia Broadcast (DTMB) and Digital Video Broadcasting-Terrestrial (DVB-T) in AWGN noise.
We adopted professional instrument to measure all parameters , while the Signal Noise Ratio (SNR) is set -50dBm and the bandwidth is 8MHz. DTMB used Time Domain Spreading Orthogonal Frequency Division Multiplexing (TDS-OFDM) to modulate the baseband signal. We analysis the MER in 4-QAM , 16-QAM and 64-QAM , while the code rate is set 0.4 , 0.6 and 0.8 , Guard Interval (GI) is set to PN sequence and 945symbols.
Test results show that the MER is the best one when the demodulation is set at 4QAM and guard interval is 945 symbols. And the difference is about 0.8 MER. so DTMB in AWGN channel is better than DVB-T in mobile.
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