Back to results
US 6,185,594 B2Granted
Versatile signal generator
AssigneeAgilent Technologies, Inc.
InventorsHoward E Hilton, John H. Guilford
Life of this patent
Estimating the term…
Abstract
A versatile signal generator for generating digitally modulated test signals computed in real-time is provided. Each of the blocks ol the versatile signal generator, including the MUX, coder, map, filter, re-sampler, and modulator, are implemented in a sufficiently flexible manner so as to allow ready configuration to produce any of a variety of digitally modulated signals as well as high quality analog modulated signals. Each of the blocks may be implemented using ASICs and RAM that allow to obtain high symbol rates while being capable of being reconfigured for different test signals as needed. The versatile signal generator has a real time input for receiving input data to modulate the test signal in real time.
Claims17
A complex signal generator comprising:
- (a) a multiplexer having a plurality of inputs and a field counter input wherein one of said inputs coupled to a real time input for receiving input data and said multiplexer selects among said plurality of inputs according to said field counter input to produce data words;
- (b) a coder coupled to said multiplexer to receive said data words wherein said coder produces symbol codes according to said data words;
- (c) a map coupled to receive said symbol codes from said coder wherein said map produces symbol values according to said symbol codes;
- and
- (d) a filter coupled to said map to receive said symbol values wherein said filter filters said symbol values to produce a complex output having a desired frequency response.
2 more elements
A complex signal generator comprising:
- a multiplexer having a plurality of inputs and a field counter input wherein one of said inputs coupled to a real time input for receiving input data and said multiplexer selects among said plurality of inputs according to said field counter input to produce data words;
- a coder coupled to said multiplexer to receive said data words wherein said coder produces symbol codes according to said data words;
- a filter coupled to said map to receive said symbol codes wherein said filter produces a complex output having a desired frequency response, wherein said filter comprises;
- (a) a shift register for storing said symbol codes wherein said symbol codes are grouped together as a set of clusters, each of said set of clusters forming packed array symbol codes;
- (b) a MUX coupled to said shift register to receive each of said clusters according to a control input to provide said packed array symbol code at a MUX output;
- (c) a mod(C) counter coupled to said MUX output and said control input wherein said mod(C) counter successively provides for the selection of each cluster by said MUX,
- (d) a RAM having an address input and a RAM output, said address input coupled to said MUX output and said RAM containing a table of tap products, said table of tap products containing the product of the symbol codes, wherein said product of the symbol codes is provided at said RAM output according to said packed array symbol code;
- and
- (e) an accumulator coupled to said RAM output for summing said product of the symbol codes over said of clusters to form said complex output.
6 more elements
A versatile signal generator, comprising:
- (a) a complex signal generator for generating a complex output wherein said complex signal generator comprises a multiplexer having a plurality of inputs and a field counter input wherein one of said inputs coupled to a real time input for receiving input data and said multiplexer selects among said plurality of inputs according to said field counter input to produce data words, a coder coupled to said multiplexer to receive said data words wherein said coder produces symbol codes according to said data words, a map coupled to receive said symbol codes from said coder wherein said map produces symbol values according to said symbol codes and a filter coupled to said map to receive said symbol values wherein said filter filters said symbol values to produce a complex output having a desired frequency response;
- (b)a resampler coupled to said complex signal generator to receive said complex output wherein said resampler produces said complex output at an output sample rate;
- (c) a complex modulator for receiving said complex output from said resampler to produce real samples and imaginary samples;
- (d) first and second digital to analog converters coupled to said complex modulator for receiving said real samples and said imaginary samples respectively wherein said first and second digital to analog converters produce real and imaginary output signals at said output sample rate;
- and
- (e) first and second low pass filters coupled to said first and second digital to analog converters to filter said real and imaginary output signals.
3 more elements
A versatile signal generator comprising:
- a complex signal generator for generating a complex output wherein said complex signal generator comprises a multiplexer having a plurality of inputs and a field counter input wherein one of said inputs coupled to a real time input for receiving input data and said multiplexer selects among said plurality of inputs according to said field counter input to produce data words, a coder coupled to said multiplexer to receive said data words wherein said coder produces symbol codes according to said data words, and a filter coupled to said map to receive said symbol values wherein said filter filters said symbol values to produce a complex output having a desired frequency response;
- a resampler coupled to said complex signal generator to receive said complex output wherein said resampler produces said complex output at an output sample rate;
- a complex modulator for receiving said complex output from said resampler to produce real samples and imaginary samples;
- first and second digital to analog converters coupled to said complex modulator for receiving said real samples and said imaginary samples respectively wherein said first and second digital to analog converters produce real and imaginary output signals at said output sample rate;
- and
- first and second low pass filters coupled to said first and second digital to analog converters to filter said real and imaginary output signals wherein said filter comprises:
- (a) a shift register for storing said symbol codes wherein said symbol codes are grouped together as a set of clusters, each of said set of clusters forming packed array symbol codes;
- (b) a MUX coupled to said shift register to receive each of said clusters according to a control input to provide said packed array symbol code at a MUX output;
- (c) a mod(C) counter coupled to said MUX output and said control input wherein said mod(C) counter successively provides for the selection of each cluster by said MUX;
- (d) a RAM having an address input and a RAM output, said address input coupled to said MUX output and said RAM containing a table of tap products, said table of tap products containing the product of the symbol codes, wherein said product of the symbol codes is provided at said RAM output according to said packed array symbol code;
- and
- (e) an accumulator coupled to said RAM output for summing said product of the symbol codes over said of clusters to form said complex output.
9 more elements
Dependencies are inferred from the claim text.