現(xiàn)代通信原理課件chapterone-文庫吧
2025-04-28 18:08 本頁面
【正文】 ation apply to all types of channels, although channel characteristics may impose constraints that favor a particular type of signaling Channel 12 The receiver takes the corrupted signal at the channel output and converts it to a baseband signal that can be handled by the receiver baseband processor, and then the receiver baseband processor estimate the source information and output the estimation result Receiver 13 The goal is to design munication system that transmit information to the receiver with as little deterioration as possible while satisfying design constrains such as allowable transmitted energy,allowable signal bandwidth and cost. In digital system measure of deterioration is taken to be bit error rate(BER),while in analog system the performance measure is usually taken to be the signaltonoise ratio(SNR) at the receiver output. Summary 14 Digital and Analog source and system ? Model of analog munication system T r an s m i t t i n g e n d I n f or m at i on s ou r c e m od u l at or c h an n e l D e m od u l at or S i n k O r ( ac c e p t an t ) R e c e i vi n g e n d n oi s e 15 Digital and Analog source and system (model of digital munication system) 16 1） Relatively inexpensive digital circuits may be used 2） Privacy is preserved by using data encryption 3） Greater dynamic range is possible 4） Data from different sources my be transmitted over a mon digital transmission system 2 the advantage of digital system Digital and Analog source and system 17 5） Noise does not accumulate in long distance systems by repeater 6） Error in detected data may be small, even in large amount of noise on the received signal 7） Error may often be corrected by the use of coding 2 the advantage of digital system Digital and Analog source and system 18 1)More bandwidth is required generally 2)Sychronization is required of Digital
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號(hào)-1