Elements of Comm.Sys Communication systems are electronic systems designed to transmit information In general,the infor/msg is Noise TRANSMITTER n(t) RE said to be generated by a information/msg source. Information Transmission r( Info must be something input Signal Carrier s( 1) processing medium circuits unknown and mathematically (channel) described by random signals, also called random processes. m The information or massage may be voic Information/message text,or a file. signal:to represent the .Voice:in telephony,a microphone is us information or message. Transmission signal:to 2.Text:in mobile SMS,a keypad system i go through the channel 3.Video:in network,a video-camera is.. UESTC-Introduction Prof李晓峰 4