Digital signal modulation analysis device
First Claim
1. A digital modulation analysis device for measuring modulation characteristics of a digital MCA (Multi The Channel Access) signal produced by a device under test (DUT) for a digital communication, comprising:
- a frequency converter (109) which receives said digital MCA signal (101) from said DUT and converts said digital MCA signal into an intermediate frequency signal;
an analog to digital (A/D) converter which receives said intermediate frequency signal and converts the same to a digital signal and store said digital signal in a memory (240) in said converter;
a Hilbert converter (310) which is connected to said A/D converter and converts an incoming digital signal into an I-component signal and a Q-component signal through a quadrant-modulate detection process;
a synchronization part (740) which receives said I-component and Q-component signals to determine a carrier s center frequency (Ω
f0) and a slot synchronization address (dly0) in said digital MCA signal (101) from said DUT;
an estimation and demodulation part (400) which receives information on said carrier s center frequency (Ω
f0) and said slot synchronization address (dly0) from said synchronization part (740) and said I-component and Q-component signals from said Hilbert converter (310) to obtain optimum parameters (gain constant Ax, initial phase θ
x, carrier frequency Ω
x, and burst droop factor σ
x) to minimize a modulation error ε
, and demodulates data (vector value A and phase angle θ
for symbol number n) for symbols in said digital MCA signal (101) from said DUT and determines reference data for said symbols (reference symbol vector value Ar and reference-symbol phase-angle value θ
r); and
a modulation-precision calculation component (900) which receives said reference data from said estimation and modulation part (400) and calculates modulation precision data and/or a modulation error for each of said symbols.
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Accused Products
Abstract
A digital signal modulation analysis device is to shorten the time for modulation analysis, and at the same time to structure a measurement device that is small in scale and inexpensive. A digital signal modulation analysis device includes a frequency convertor which converts a signal from a device under test to a first intermediate frequency signal, a sampling part which converts the first intermediate frequency signal to a second intermediate-frequency signal whose frequency is lower than that of the first intermediate frequency to store the second intermediate frequency signal in a memory, a Hilbert converter which converts an incoming signal into orthogonal component signals through a quadrant-modulate detection process, an initial synchronization part which determines a carrier center frequency, a symbol-demodulation/parameter-estimation part which determines optimal parameters to minimize a modulation error and demodulates all symbol data to determine reference data for the all symbol data, and a modulation-precision calculation component which calculates modulation-precision data and modulation-error data for each symbol.
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Citations
13 Claims
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1. A digital modulation analysis device for measuring modulation characteristics of a digital MCA (Multi The Channel Access) signal produced by a device under test (DUT) for a digital communication, comprising:
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a frequency converter (109) which receives said digital MCA signal (101) from said DUT and converts said digital MCA signal into an intermediate frequency signal; an analog to digital (A/D) converter which receives said intermediate frequency signal and converts the same to a digital signal and store said digital signal in a memory (240) in said converter; a Hilbert converter (310) which is connected to said A/D converter and converts an incoming digital signal into an I-component signal and a Q-component signal through a quadrant-modulate detection process; a synchronization part (740) which receives said I-component and Q-component signals to determine a carrier s center frequency (Ω
f0) and a slot synchronization address (dly0) in said digital MCA signal (101) from said DUT;an estimation and demodulation part (400) which receives information on said carrier s center frequency (Ω
f0) and said slot synchronization address (dly0) from said synchronization part (740) and said I-component and Q-component signals from said Hilbert converter (310) to obtain optimum parameters (gain constant Ax, initial phase θ
x, carrier frequency Ω
x, and burst droop factor σ
x) to minimize a modulation error ε
, and demodulates data (vector value A and phase angle θ
for symbol number n) for symbols in said digital MCA signal (101) from said DUT and determines reference data for said symbols (reference symbol vector value Ar and reference-symbol phase-angle value θ
r); anda modulation-precision calculation component (900) which receives said reference data from said estimation and modulation part (400) and calculates modulation precision data and/or a modulation error for each of said symbols. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification