Signal converter using multiple data streams and method therefor
First Claim
1. A signal converter for processing an incoming digital data stream into an analog signal, said signal converter comprising:
- means, responsive to said incoming digital data stream, for generating a plurality of subset data streams;
a precompensation network for crosscoupling said subset data streams to produce a plurality of crosscoupled data streams;
a plurality of digital to analog converters responsive to respective ones of said crosscoupled data streams; and
an analog summing circuit coupled to each of said digital to analog converters for producing said analog signal.
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Accused Products
Abstract
A signal converter (20) processes an incoming digital data stream (24) to produce an analog signal (26). A pulse shaping network (28) is configured to receive the incoming digital data stream (24) and generate a plurality of subset data streams (30). A precompensation network (32) then crosscouples the subset data streams (30) to produce crosscoupled data streams (38). Each of crosscoupled data streams (38) are then converted by respective ones of digital to analog converters (22) to produce intermediate analog signals (44). The intermediate analog signals (44) are summed by an operational amplifier (46) to produce the analog signal (26). The precompensation network (32) can be combined with the pulse shaping network (28) by using a common look-up memory element (70) to perform both functions.
25 Citations
24 Claims
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1. A signal converter for processing an incoming digital data stream into an analog signal, said signal converter comprising:
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means, responsive to said incoming digital data stream, for generating a plurality of subset data streams; a precompensation network for crosscoupling said subset data streams to produce a plurality of crosscoupled data streams; a plurality of digital to analog converters responsive to respective ones of said crosscoupled data streams; and an analog summing circuit coupled to each of said digital to analog converters for producing said analog signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. In a digital communication modulator, a method for providing a modulated analog signal comprising the steps of:
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receiving an incoming digital data stream extending over a plurality of symbols; producing intra-symbol samples in response to said incoming digital data stream; converting, in a plurality of digital to analog converters, said intra-symbol samples into a corresponding plurality of intermediate analog signals; and combining said plurality of intermediate analog signals to produce said modulated analog signal. - View Dependent Claims (18, 19, 20, 21, 22, 23)
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24. A digital communication modulator for processing an incoming digital data stream extending over a plurality of symbols into a modulated analog signal, said modulator comprising:
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a shift register responsive to said incoming digital data stream for receiving incoming samples in accordance with a sequence; a look-up memory element configured to produce a plurality of subset data streams, each of said subset data streams being formed from an intra-symbol sample for each of said incoming samples, each of said intra-symbol samples being responsive to a difference between each one of said intra-symbol samples and a previous one of said intra-symbol samples, a difference between first and second ones of said intra-symbol samples from a previous one of said symbols, and a predetermined weighting function defining a modulation pulse shape; a plurality of digital to analog converters responsive to respective ones of said subset data streams for producing temporally staggered intermediate analog signals; and an operational amplifier coupled to each of said digital to analog converters and configured to combine said intermediate analog signals to produce said modulated analog signal.
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Specification