Apparatus for synthesizing phase-modulated carrier wave

Claim 2

Apparatus for synthesizing a phase-modulated carrier wave according to digital data elements sequentially applied thereto, comprising: a memory for storing a plurality of predefined carrier-wave segments, each segment having a unique phase and being represented by a set of a plurality of digitally encoded samples; means for selecting, according to the current data element and the phase of the last selected carrier-wave segment, the next carrier-wave segment to be read from the memory; means for addressing the memory to sequentially read the samples representing each selected carrier-wave segment; and means connected to the output of the memory for combining at least some of the samples of the last selected carrier-wave segment with at least some of the samples of the next selected carrier-wave segment to generate the phase-modulated carrier wave at the output of the combining means as successive samples are applied by the memory thereto.

Claim 3

Apparatus of claim 1 wherein the selecting means comprises: an input register for storing the latest digital data element; at least one address register for storing the address of a selected carrier-wave segment; and means, responsive to the contents of the input register and the address register, for generating the address of a carrier-wave segment to be read, and for loading the generated address into the address register after the last sample of the preceding segment addressed thereby is read.

Claim 4

Apparatus according to claim 2 which further comprises: a complement circuit connected between the memory and the combining means, and means for enabling the complement circuit during the reading of one of the samples from the memory according to a portion of the address in the address register.

Claim 5

Apparatus according to claim 3 wherein the complement circuit comprises means for forming the 1's complement of the output of the memory.

Claim 6

Apparatus according to claim 3 wherein the complement circuit comprises means for forming the 2's complement of the output of the memory.

Claim 7

Apparatus for synthesizing a phase-modulated carrier wave according to digital data elements applied thereto, comprising: first and second memories for storing a plurality of carrier-wave segments, each segment having a unique phase and being represented by a set of digitally encoded samples; a parallel adder having a first input connected to the output of the first memory and a second input connected to the output of the second memory; a digital-to-analog converter connected to the output of the adder; means for selecting, according to the current data element and the phase of the last selected carrier-wave segment, the next carrier-wave segment to be read from either the first or second memory; and means for addressing the first and second memories to sequentially read the samples of each selected wave segment and to read at least some samples simultaneously from the first and second memories, to thereby add the simultaneously read samples in the parallel adder to generate the phase-modulated carrier wave at the output of the digital-to-analog converter as the successive samples are applied by the adder to the converter.

Claim 8

Apparatus for synthesizing a phase-modulated carrier wave according to digital data elements applied thereto, comprising: first and second memories for storing a plurality of carrier-wave segments, each segment having a unique phase and being represented by a set of digitally encoded samples; a parallel adder having a first input connected to the output of the first memory and a second input connected to the output of the second memory; a digital-to-analog converter connected to the output of the adder; means for selecting, according to the current data element and the phase of the last selected carrier-wave segment, the next carrier-wave segment to be read from either the first or second memory; and means for addressing the first and second memories to sequentially read the samples of each selected wave segment and to read at least some samples simultaneously from the first and second memories, to thereby add the simultaneously read samples in the parallel adder to generate the phase-modulated carrier wave at the output of the digital-to-analog converter as the successive samples are applied by the adder to the converter.

Claim 9

Apparatus of claim 6 wherein the selecting means comprises: an input register for storing the latest digital data element; first and second address registers, associated respectively with the first and second memories, for storing addresses of selected carrier-wave segments; means, responsive to the contents of the input register and alternately to the first and second address registers, for generating the address of the next carrier-wave segment to be read; and means for loading the generated address alternately into the second and first address registers after the last sample of the previous segment addressed thereby is read.

Claim 10

Apparatus according to claim 7 which further comprises: a first complement circuit connected between the first memory and the first input of the parallel adder, means for enabling the complement circuit during the reading of one of the samples from the first memory according to a portion of the address in the first address register, a second complement circuit connected between the second memory and the second input of the parallel adder, and means for enabling the second complement circuit during the reading of one of the samples from the second memory according to a portion of the address in the second address register.

Claim 11

Apparatus according to claim 8 wherein the first and second complement circuits each comprise means for forming the 1's complement of the output of the memory to which it is connected.

Claim 12

Apparatus according to claim 8 wherein the first and second complement circuits each comprise means for forming the 2's complement of the output of the memory to which it is connected.

Claim 13

Apparatus of claim 6 wherein the digitally encoded samples of each wave segment are scaled according to an envelope function to facilitate blending overlapped segments together.

Claim 14

Apparatus for synthesizing a phase-modulated carrier-wave according to digital data elements applied thereto, comprising: a memory for storing a plurality of carrier-wave segments, each segment having a unique phase, and being represented by a set of digitally encoded samples; an intermediate register; means for loading the intermediate register from the output of the memory; an adder having a first input connected to the output of the memory, and a second input connected to the output of intermediate register; an output register; means for loading the output register from the output of the adder; a digital-to-analog converter connected to the output register; first and second address registers for storing addresses of selected carrier-wave segments; means for alternately a reading from the memory the next sample of the carrier-wave segment addressed by the first address register and enabling the means for loading the intermediate register, so that the next sample of the carrier-wave segment addressed by the first address register is loaded into the intermediate register, and b reading from the memory the next sample of the carrier-wave segment addressed by the second address register and enabling the means for loading the output register so that the sum of the next sample of the carrier-wave segment addressed by the second address register and the next sample of the carrier-wave segment addressed by the first address register, previously stored in the intermediate register, is loaded into the output register; the phase-modulated carrier wave being generated at the output of the digital-to-analog converter as the successive samples are applied thereto from the output register.

Claim 15

Apparatus for synthesizing a phase-modulated carrier-wave according to digital data elements applied thereto, comprising: a memory for storing a plurality of carrier-wave segments, each segment having a unique phase, and being represented by a set of digitally encoded samples; an intermediate register; means for loading the intermediate register from the output of the memory; an adder having a first input connected to the output of the memory, and a second input connected to the output of intermediate register; an output register; means for loading the output register from the output of the adder; a digital-to-analog converter connected to the output register; first and second address registers for storing addresses of selected carrier-wave segments; means for alternately a reading from the memory the next sample of the carrier-wave segment addressed by the first address register and enabling the means for loading the intermediate register, so that the next sample of the carrier-wave segment addressed by the first address register is loaded into the intermediate register, and b reading from the memory the next sample of the carrier-wave segment addressed by the second address register and enabling the means for loading the output register so that the sum of the next sample of the carrier-wave segment addressed by the second address register and the next sample of the carrier-wave segment addressed by the first address register, previously stored in the intermediate register, is loaded into the output register; the phase-modulated carrier wave being generated at the output of the digital-to-analog converter as the successive samples are applied thereto from the output register.

Claim 16

Apparatus of claim 12 wherein the digitally encoded samples of each wave segment are scaled according to an envelope function to facilitate blending overlapped segments together.

Claim 17

Apparatus according to claim 12 which further comprises: an input register for storing the latest digital data element; means, responsive to the contents of the input register and alternately to the first and second address registers, for generating the address of the next carrier-wave segment to be read; and means for loading the generated address alternately into the second and first address registers after the last sample of the previous segment addressed thereby is read.

Claim 18

Apparatus according to claim 14 which further comprises: a complement circuit connected between the memory and the connections to the intermediate register loading means and to the first input of the adder; and means for enabling the complement circuit during the reading of a given sample from the memory, according to a portion of the address in the address register selecting the given sample.

Claim 19

Apparatus according to claim 15 wherein the complement circuit comprises means for forming the 1's complement of the output of the memory.

Claim 20

Apparatus according to claim 15 wherein the complement circuit comprises means for forming the 2's complement of the output of the memory.

Claim 21

Apparatus for synthesizing a phase-modulated carrier-wave according to digital data elements applied thereto, comprising: a memory for storing a plurality of carrier-wave segments, each segment having a unique phase and being represented by a set of digitally encoded samples; a 1's complement circuit having an input connected to the output of the memory, and an enabling input; an adder having a first input connected to the output of the 1's complement circuit, a second input, and a carry input; an intermediate register; means for loading the intermediate register from the output of the adder; means for gating the contents of the intermediate register into the second input of the adder; an output register; means for loading the output register from the output of the adder; a digital-to-analog converter connected to the output register; first and second address registers for storing addresses of selected carrier-wave segments, means for alternately a reading from the memory the next sample of the carrier-wave segment addressed by the first address register and enabling the means for loading the intermediate register so that the next sample of the carrier-wave segment addressed by the first address register is loaded into the intermediate register, and b reading from the memory the next sample of the carrier-wave segment addressed by the second address register and enabling both the means for loading the output register and the gating means so that the sum of the next sample of the carrier-wave segment addressed by the second address register and the next sample of the carrier-wave segment addressed by the first address register, previously stored in the intermediate register, is loaded into the output register; means, responsive to the contents of the input register and alternately to the first and second address registers, for generating the address of the next carrier-wave segment to be read; and means for loading the generated address alternately into the second and first address registers after the last sample of the previous segment addressed thereby is read; means for enabling both the 1's complement circuit and the carry input of the adder during the reading of a given sample from the memory, according to a portion of the address in the address register selecting the given sample; the phase-modulated carrier wave being generated at the output of the digital-to-analog converter as the successive samples are applied to the converter by the output register.

Claim 22

Apparatus for synthesizing a phase-modulated carrier-wave according to digital data elements applied thereto, comprising: a memory for storing a plurality of carrier-wave segments, each segment having a unique phase and being represented by a set of digitally encoded samples; a 1's complement circuit having an input connected to the output of the memory, and an enabling input; an adder having a first input connected to the output of the 1's complement circuit, a second input, and a carry input; an intermediate register; means for loading the intermediate register from the output of the adder; means for gating the contents of the intermediate register into the second input of the adder; an output register; means for loading the output register from the output of the adder; a digital-to-analog converter connected to the output register; first and second address registers for storing addresses of selected carrier-wave segments, means for alternately a reading from the memory the next sample of the carrier-wave segment addressed by the first address register and enabling the means for loading the intermediate register so that the next sample of the carrier-wave segment addressed by the first address register is loaded into the intermediate register, and b reading from the memory the next sample of the carrier-wave segment addressed by the second address register and enabling both the means for loading the output register and the gating means so that the sum of the next sample of the carrier-wave segment addressed by the second address register and the next sample of the carrier-wave segment addressed by the first address register, previously stored in the intermediate register, is loaded into the output register; means, responsive to the contents of the input register and alternately to the first and second address registers, for generating the address of the next carrier-wave segment to be read; and means for loading the generated address alternately into the second and first address registers after the last sample of the previous segment addressed thereby is read; means for enabling both the 1's complement circuit and the carry input of the adder during the reading of a given sample from the memory, according to a portion of the address in the address register selecting the given sample; the phase-modulated carrier wave being generated at the output of the digital-to-analog converter as the successive samples are applied to the converter by the output register.

Claim 23

Apparatus of claim 18 wherein the digitally encoded samples of wave segments are scaled according to an envelope function to facilitate blending overlapped segments together.

Claim 24

Apparatus for synthesizing a phase-modulated carrier wave according to digital data elements applied thereto, comprising: a memory for storing a plurality of carrier-wave segments, each having a unique phase and comprising a set of digitally encoded samples; a digital-to-analog converter connected to the output of the memory; first and second address registers for storing addresses of selected carrier-wave segments; means for alternately a reading from the memory the next sample of the wave segment addressed by the first register, and b reading from the memory the next sample of the wave segment addressed by the second register; a low-pass filter, connected to the output of the digital-to-analog converter, for attenuating wave components having frequencies at or greater than the rate at which samples are applied to the digital-to-analog converter; an input register for storing the latest digital data element; means, responsive to the contents of the input register and alternately to the first and second address registers, for generating the address of the next carrier-wave segment to be read; and means for loading the generated address alternately into the second and first register after the last sample of the previous segment addressed thereby is read; the phase-modulated carrier wave being generated at the output of the low-pass filter as the successive samples are applied to the digital-to-analog converter from the memory.

Claim 25

Apparatus for synthesizing a phase-modulated carrier wave according to digital data elements applied thereto, comprising: a memory for storing a plurality of carrier-wave segments, each having a unique phase and comprising a set of digitally encoded samples; a digital-to-analog converter connected to the output of the memory; first and second address registers for storing addresses of selected carrier-wave segments; means for alternately a reading from the memory the next sample of the wave segment addressed by the first register, and b reading from the memory the next sample of the wave segment addressed by the second register; a low-pass filter, connected to the output of the digital-to-analog converter, for attenuating wave components having frequencies at or greater than the rate at which samples are applied to the digital-to-analog converter; an input register for storing the latest digital data element; means, responsive to the contents of the input register and alternately to the first and second address registers, for generating the address of the next carrier-wave segment to be read; and means for loading the generated address alternately into the second and first register after the last sample of the previous segment addressed thereby is read; the phase-modulated carrier wave being generated at the output of the low-pass filter as the successive samples are applied to the digital-to-analog converter from the memory.

Claim 26

Apparatus of claim 20 wherein the digitally encoded samples of each wave segment are scaled according to an envelope function to facilitate blending overlapped segments together.

Claim 27

Apparatus according to claim 21 which further comprises: a complement circuit connected between the memory and the digital-to-analog converter, the complement circuit being enabled or disabled during the reading of a given sample from the memory, according to a portion of the address in the address register selecting the given sample.

Claim 28

Apparatus according to claim 22 wherein the complement circuit comprises means for forming the 1's complement of the output of the memory.

Claim 29

Apparatus according to claim 22 wherein the complement circuit comprises means for forming the 2's complement of the output of the memory.

Claim 30

Apparatus for synthesizing a phase-modulated carrier wave according to digital data elements sequentially applied thereto, comprising: a memory for storing a plurality of carrier-wave segments, each segment having a unique phase and being represented by a set of a plurality of digitally encoded samples; means for selecting, according to the current data element and the phase of the last selected carrier-wave segment, the next carrier-wave segment to be read from memory; means for addressing the memory to alternately read digital samples representing the last selected carrier-wave segment and digital samples representing the next carrier-wave segment to produce a serial output of the two overlapping carrier-wave segments, the digital samples of each of the carrier-wave segments being interleaved with the digital samples of the other; and means connected to the output of the memory for combining successive digital samples of the serial output on a sample-by-sample basis to generate the phase-modulated carrier-wave.

Claim 31

Apparatus for synthesizing a phase-modulated carrier wave according to digital data elements sequentially applied thereto, comprising: a memory for storing a plurality of carrier-wave segments, each segment having a unique phase and being represented by a set of a plurality of digitally encoded samples; means for selecting, according to the current data element and the phase of the last selected carrier-wave segment, the next carrier-wave segment to be read from memory; means for addressing the memory to alternately read digital samples representing the last selected carrier-wave segment and digital samples representing the next carrier-wave segment to produce a serial output of the two overlapping carrier-wave segments, the digital samples of each of the carrier-wave segments being interleaved with the digital samples of the other; and means connected to the output of the memory for combining successive digital samples of the serial output on a sample-by-sample basis to generate the phase-modulated carrier-wave.

Claim 32

Apparatus according to claim 25 wherein the means for combining the successive digital samples includes a digital-to-analog converter connected to the output of the memory and a lowpass filter connected to the output of the digital converter for attentuating wave components having frequencies at or greater than the rate at which the samples are applied to the digital-to-analog converter.

Claim 33

Apparatus according to claim 25 wherein the selecting means comprises: an input register for storing the latest digital data element; at least one address register for storing the address of a selected carrier-wave segment; and means, responsive to the contents of the input register and the address register, for generating the address of a carrier-wave segment to be read, and for loading the generated address into the address register after the last sample of the preceding segment addressed thereby is read.

Claim 34

Apparatus according to claim 25 wherein the means for combining the successive digital samples includes an intermediate register; an adder having a first input connected to the output of the memory; and a second input connected to the output of the intermediate register; an output register; and means for alternately a loading the digital samples of one of the overlapping segments from the memory into the intermediate register and b loading the digital samples of the other of the overlapping segments from the memory simultaneously with the previously read digital samples from the intermediate register into the output register via the adder; a digital-to-analog converter connected to the output of the output register for converting the contents of the output register to the phase-modulated carrier.