Apparatus and method for verifying performance of RF receiver

Claim 1

An apparatus for verifying performance of an RF receiver, comprising: arbitrary waveform generator means for outputting an analog in-phase waveform and an analog quadrature waveform in in accordance with sampled digital waveform data, said arbitrary waveform generator means including parallel first and second first in, first out random access memories for storing the sampled digital waveform data, the sampled digital waveform data comprising an in-phase waveform file stored in said first in first out memory and a quadrature waveform file stored in said second first in first out memory, each of the in-phase and quadrature waveform files including 60% root-cosine differential quadrature phase shift keyed data corresponding to successive frames of primary transmission channel data, co-channel interference data, adjacent channel interference data, and data relating to at least one of a plurality of impairments; unity gain reconstruction filter means, connected to said arbitrary waveform generator means, for smoothing the analog in-phase and quadrature waveforms; vector signal generator means, responsive to the filtered analog in-phase and quadrature waveforms, for outputting a modulated RF signal; and means for coupling an input of the RF receiver to the modulated RF signal output from said vector signal generator.

Claim 2

An apparatus for verifying performance of an RF receiver, comprising: arbitrary waveform generator means for outputting an analog in-phase waveform and an analog quadrature waveform in in accordance with sampled digital waveform data, said arbitrary waveform generator means including parallel first and second first in, first out random access memories for storing the sampled digital waveform data, the sampled digital waveform data comprising an in-phase waveform file stored in said first in first out memory and a quadrature waveform file stored in said second first in first out memory, each of the in-phase and quadrature waveform files including 60% root-cosine differential quadrature phase shift keyed data corresponding to successive frames of primary transmission channel data, co-channel interference data, adjacent channel interference data, and data relating to at least one of a plurality of impairments; unity gain reconstruction filter means, connected to said arbitrary waveform generator means, for smoothing the analog in-phase and quadrature waveforms; vector signal generator means, responsive to the filtered analog in-phase and quadrature waveforms, for outputting a modulated RF signal; and means for coupling an input of the RF receiver to the modulated RF signal output from said vector signal generator.

Claim 3

A method of verifying the performance of a satellite digital receiver comprising the steps of: generating an information file stream of ones and zeroes representing digital information, the digital information being a type input to a digital portion of a ground segment for processing and transmission to a mobile transceiver via a satellite; transforming the information file stream into a satellite signal format of encoded framed data; separating the encoded framed data into in-phase and quadrature data streams which are root-cosine filtered to produce sampled in-phase and quadrature data streams; summing digitally calibrated simulated channel impairments and the sampled in-phase and quadrature data streams to provide respective summed in-phase and quadrature data streams; scaling the summed in-phase and quadrature data streams from a floating point representation to a fixed point representation; downloading the fixed point in-phase and quadrature data streams into two parallel real time first in/first out memories of an arbitrary waveform generator to produce analog in-phase and quadrature waveforms in accordance with the downloaded fixed point in-phase and quadrature data streams; combining the analog in-phase and quadrature waveforms in a vector modulator to produce an RF digital quadrature phase shift keyed signal output; applying the RF digital quadrature phase shift keyed signal to an analog subsection of the satellite digital receiver; actuating the satellite digital receiver to produce an output; and monitoring the satellite digital receiver output.

Claim 4

A method of verifying the performance of a satellite digital receiver comprising the steps of: generating an information file stream of ones and zeroes representing digital information, the digital information being a type input to a digital portion of a ground segment for processing and transmission to a mobile transceiver via a satellite; transforming the information file stream into a satellite signal format of encoded framed data; separating the encoded framed data into in-phase and quadrature data streams which are root-cosine filtered to produce sampled in-phase and quadrature data streams; summing digitally calibrated simulated channel impairments and the sampled in-phase and quadrature data streams to provide respective summed in-phase and quadrature data streams; scaling the summed in-phase and quadrature data streams from a floating point representation to a fixed point representation; downloading the fixed point in-phase and quadrature data streams into two parallel real time first in/first out memories of an arbitrary waveform generator to produce analog in-phase and quadrature waveforms in accordance with the downloaded fixed point in-phase and quadrature data streams; combining the analog in-phase and quadrature waveforms in a vector modulator to produce an RF digital quadrature phase shift keyed signal output; applying the RF digital quadrature phase shift keyed signal to an analog subsection of the satellite digital receiver; actuating the satellite digital receiver to produce an output; and monitoring the satellite digital receiver output.

Claim 22

An apparatus for verifying performance of an RF receiver comprising: waveform data generating means for generating waveform samples which emulate framed, encoded satellite signals including satellite channel impairments; waveform generating means, coupled to said waveform data generating means, for converting the waveform samples into analog waveforms; filter means, coupled to said waveform generating means, for smoothing the analog waveforms; modulation means, coupled to said filter means, for outputting a phase modulated RF signal in accordance with the smoothed analog waveforms; and coupling means for coupling the modulated RF signal to an input of the RF receiver.

Claim 23

An apparatus for verifying performance of an RF receiver comprising: waveform data generating means for generating waveform samples which emulate framed, encoded satellite signals including satellite channel impairments; waveform generating means, coupled to said waveform data generating means, for converting the waveform samples into analog waveforms; filter means, coupled to said waveform generating means, for smoothing the analog waveforms; modulation means, coupled to said filter means, for outputting a phase modulated RF signal in accordance with the smoothed analog waveforms; and coupling means for coupling the modulated RF signal to an input of the RF receiver.

Claim 33

A method of verifying performance of an RF receiver comprising the steps of: (a) generating waveform samples which emulate framed, encoded satellite signals including satellite channel impairments; (b) converting the waveform samples into analog waveforms; (c) filtering the analog waveforms to provide smoothed analog waveforms; (d) phase modulating the smoothed analog waveforms to provide a phase-modulated RF signal; and (e) coupling the phase-modulated RF signal to an input of the RF receiver.

Claim 34

A method of verifying performance of an RF receiver comprising the steps of: (a) generating waveform samples which emulate framed, encoded satellite signals including satellite channel impairments; (b) converting the waveform samples into analog waveforms; (c) filtering the analog waveforms to provide smoothed analog waveforms; (d) phase modulating the smoothed analog waveforms to provide a phase-modulated RF signal; and (e) coupling the phase-modulated RF signal to an input of the RF receiver.