Overall Solution for PCM Time-Division Multiplexing Digital Baseband Transmission

PCM time-division multiplexing digital baseband transmission enables communication by allowing various signals to occupy different time slots on the same channel. It converts analog signals into digital signals through sampling, quantization, and encoding, all accomplished by the codec, and then multiplexes them under the control of bit synchronization and frame synchronization signals via a multiplexer. The multiplexed signal is transmitted through the channel, and the demultiplexer separates the received signal into individual channels under the action of synchronization signals. The demultiplexed signals are then processed through [PCM](

   The crystal oscillator, frequency divider 1, frequency divider 2, and sampling signal (timeslot synchronization signal) generator form a timer that provides a 2.048MHz clock signal and an 8KHz timeslot synchronization signal to the two PCM codecs. Here, the clock signal and timeslot synchronization signal generated by the synchronizer are directly sent to the decoder.

   Since the clock frequency is 2.048MHz and the sampling signal frequency is 8KHz, the bit rates of both PCM-A and PCM-B are 2.048MB, with 32 timeslots per frame, of which 1 timeslot carries PCM encoded data and the remaining 31 timeslots are idle timeslots.