PCM-method summarized
{"Image DocumentName": "PCM-method summarized", "Image ImageDescription": "Analog speech signal is applied into a LP-filter restricting its bandwidth into 3.4 kHz. Sampling circuit forms a PAM pulse train having rate of 8 kHz. Samples are quantized into 256 levels that requires a 8 bit-word for each sample (28=256). Thus a telephone signal requires 8x8 kHz = 64 kHz bandwidth. The samples are line coded by using the HDB-3 scheme to alleviate synchronization problems at the receiver. Usually one transmits several channels simultaneously following SDH hierarchy (as 30 pcs) Transmission link can be an optical fiber, radio link or an electrical cable. At the receiver the PAM signal is first reconstructed where after it is lowpass filtered to yield the original-kind, analog signal.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}