Digital signal generator
AssigneeGTE Sylvania Incorporated
InventorsRobert G. Field, Marvin S. Mason
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Abstract
Digital signal generator for producing digital signalling codes employed in a digital telephone communication system including several tone generators for providing presynthesized digital tone signals which are convertible to audible tones. Permutable digital codewords are produced by a codeword generator. Some of the tone signals and codewords are combined by FSK and switching circuitry. Tone signals, codeword signals, and combination signals are stored in storage registers and read out by a multiplexer to provide a continuous TDM bit stream of 60 channels of digital signalling codes.
Claims5
Digital signalling code generating apparatus including
- tone generating means for producing a plurality of recurring sequences of digital signals, each capable of being converted to a continuous audible tone;
- codeword generating means for producing a plurality of recurring sequences of digital signals, each providing a continuously repeated codeword;
- combining means coupled to said tone generating means and said codeword generating means for producing a plurality of recurring sequences of digital signals which are combinations of sequences of digital signals produced by said tone generating means, and said codeword generating means;
- and
- storage means coupled to said tone generating means, said codeword generating means, and said combining means for storing digital signals from said tone generating means, said codeword generating means, and said combining means;
- and
- mulitplexing means coupled to said storage means and to an output line for time division mulitplexing digital signals in said storage means onto the output line in a plurality of channels whereby a different predetermined digital signalling code pattern is continuously available in each channel.
Dependencies are inferred from the claim text.