SIGNAL COMPRESSION AND EXPANSION SYSTEM USING A MEMORY

摘要

The compander system uses a register having a limited number of possible digital states, or counts, each weighted to represent a certain voltage. Each count is used to address a location in a memory which stores digital numbers having a different number of bit positions relative to the bit positions of the count in the register. Each number is weighted to represent a different voltage from the voltage value represented by the register count. An analog signal is generated in response to the stored digital number for comparison with the input signal even though the register count is changed as if the voltage represented by its count had been used for making the comparison. The process is continued until the signals are within the limits provided by the least significant digit of the stored number. The number in the register is then transmitted to the receiver where the digital signal is converted into an analog signal using an additional memory and register having a limited number of bit positions.