Characterization of digital radio signals

Claim 3

A method according to claim 1, including the step exaggerating said differences by increasing the counts accumulated for those sub-ranges encompassing the higher levels of amplitude dispersion relates to the counts accumulated for those sub ranges encompassing the lower levels of amplitude dispersion.

Claim 4

A method according to claim 1 including the step of exaggerating said differences by arranging that the sub-ranges which encompass higher levels of sampled amplitude dispersion of one sign overlap those which encompass lower levels of sampled amplitude dispersions of the same sign.

Claim 5

A method according to claim 1 including the steps of exaggerating said differences by arranging the sub-ranges to be non-overlapping and contiguous, and generating the count corresponding to each sub-range employed in said graphical representation by adding the sum of the first count for that sub-range (if any) encompassing a lower level of amplitude dispersion of the same sign.

Claim 12

A method according to either claim 7 or 8 including the steps of: accumulating total counts of the number of dispersion measurement falling within each of said ranges without regard to said error rate, determining the ratio of said first counts to said total counts for each range where there are first counts, and generating a graphical representation by displaying said ratio against range instead of said first count against range.

Claim 13

Electronic test equipment for characterising a modulated carrier signal during a test period, said equipment comprising: measuring means for measuring the amplitude dispersion of the signal and for generating, at time-spaced intervals, outputs having values indicative of the magnitude and sign of the amplitude dispersion at the respective intervals, classifier means, connected to receive said outputs of said measuring means, for generating in respect of each of said outputs a range signal indicating in which one of a series of possible ranges of said output values that output value falls, first counter means, connected to receive said range signals from said classified means, for accumulating first points of the number of times each range is indicated, and read-out means for reading out at the end of the test period the first counts accumulated, range by range, so that a graphical display device can generate a display of first count against range.

Claim 14

Electronic test equipment for characterising a modulated carrier signal during a test period, said equipment comprising: measuring means for measuring the amplitude dispersion of the signal and for generating, at time-spaced intervals, outputs having values indicative of the magnitude and sign of the amplitude dispersion at the respective intervals, classifier means, connected to receive said outputs of said measuring means, for generating in respect of each of said outputs a range signal indicating in which one of a series of possible ranges of said output values that output value falls, first counter means, connected to receive said range signals from said classified means, for accumulating first points of the number of times each range is indicated, and read-out means for reading out at the end of the test period the first counts accumulated, range by range, so that a graphical display device can generate a display of first count against range.

Claim 15

Electronic test equipment according to claim 10 where, in addition to the modulated carrier signal, a second signal indicative of the instantaneous quality of the carrier signal is available, said test equipment comprising: monitoring means for receiving said second signal and for generating an output signal whenever the second signal lies within a predetermined range, count control means connected between said monitoring means and said first counter means for inhibiting the accumulation of said first counts when said output signal is generated by said monitoring means.

Claim 16

Electronic equipment according to claim 11 comprising: second counter means, connected to receive said range signals from said classifier means, for accumulating second counts of the number of times each range is indicated, and divider means connected to said first and said second counter means for generating an output indicative of the ratio of said first and said second counts accumulated in respect of each range, and said readout means includes selector means connected to select either accumulated count or said ratio for read-out to the graphical display device.

Claim 17

An instrument for indicating the performance of a digital microwave receiver when the received signal may be subject to multipath fading and an error signal indicative of the instantaneous error rate in the demodulated output of the receiver is available, said instrument comprising: measuring means for measuring the amplitude dispersion of the received signal and for generating, at time-spaced intervals, outputs having values indicative of the magnitude and sign of the amplitude dispersion at the respective intervals, classifier means, connected to receive said outputs of said measuring means, for generating in respect of each of said outputs a range signal indicating in which one of a series of possible ranges of said output values that output value falls, first counter means, connected to receive said range signals from said classifier means, for accumulating first counts of the number of times each range is indicated, and graphical display means connected to said first counter means for generating a graphical representation of count against range wherein said first counts for ranges in which the amplitude dispersion is positive are displayed together with those for which the amplitude dispersion is negative so that any differences therebetween will be apparent.

Claim 18

An instrument for indicating the performance of a digital microwave receiver when the received signal may be subject to multipath fading and an error signal indicative of the instantaneous error rate in the demodulated output of the receiver is available, said instrument comprising: measuring means for measuring the amplitude dispersion of the received signal and for generating, at time-spaced intervals, outputs having values indicative of the magnitude and sign of the amplitude dispersion at the respective intervals, classifier means, connected to receive said outputs of said measuring means, for generating in respect of each of said outputs a range signal indicating in which one of a series of possible ranges of said output values that output value falls, first counter means, connected to receive said range signals from said classifier means, for accumulating first counts of the number of times each range is indicated, and graphical display means connected to said first counter means for generating a graphical representation of count against range wherein said first counts for ranges in which the amplitude dispersion is positive are displayed together with those for which the amplitude dispersion is negative so that any differences therebetween will be apparent.

Claim 19

An instrument according to claim 13 comprising: monitoring means for receiving the error signal and for generating an output signal whenever the corresponding error rate lies within a predetermined range, count control means connected between said monitoring means and said first counter means for inhibiting the accumulation of said first counts when said output signal is generated by said monitoring means.

Claim 20

An instrument according to claim 14 comprising: second counter means, connected to receive said range signals from said classifier means, for accumulating second counts of the number of times each range is indicated, and selector means connected to select between the accumulated first count, the accumulated second count and said ratio of said counts for transmission to said graphical display means, range by range.

Claim 21

An instrument according to claim 14 comprising: second counter means, connected to receive said range signal from said classifier means, for accumulating second counts of the number of times each range is indicated, and divider means connected to said first and said second counter means for generating an output indicative of the ratio of said first and said second counts accumulated in respect of each range, and selector means connected to select between the accumulated first count, the accumulated second count and said ratio of said counts for transmission to said graphical display mans, range by range.