Device and method for measuring vector modulation error of device

Abstract

The invention discloses a device and a method for measuring a vector modulation error of a device, and particularly relates to the technical field of vector modulation. The device comprises a reference signal path and a measurement signal path, wherein the reference signal path comprises a first analog-to-digital converter and a first IQ demodulator which are connected in sequence, the measurementsignal path comprises an IQ modulator, a second analog-to-digital converter and a second IQ demodulator which are connected in sequence, and a measured device is arranged between the IQ modulator andthe second analog-to-digital converter. The device generates an IQ baseband signal, one path of the IQ baseband signal enters an IQ modulator, and a carrier is modulated to form a vector signal; andthe other path serves as a baseband synchronization signal and enters the first analog-to-digital converter for synchronization. One path of the vector signal passes through a measured piece, a secondanalog-to-digital converter and a second IQ demodulator to generate an IQ baseband measurement signal; and the other path passes through a first analog-to-digital converter and a first IQ demodulatorto generate an IQ baseband reference signal, and the IQ baseband reference signal is subtracted from the IQ baseband measurement signal to obtain a vector error.

Description

technical field [0001] The invention relates to the technical field of vector modulation, in particular to a device and method for measuring device vector modulation errors. Background technique [0002] The vector modulation technology is widely used in the communication field. The modulation principle is to modulate the baseband IQ signals on the quadrature carrier and add them together to form a vector modulation signal. Common modulation methods are ASK, PSK, etc. Modulation accuracy directly determines the bit error rate of signal transmission, so it is very important for communication. At present, the commonly used index to reflect the modulation accuracy is the vector modulation error, which reflects the error between the measured signal and the reference signal. The reference signal refers to the baseband signal obtained after demodulating an ideal error-free vector modulation signal. The vector modulation error can be calculated by comparing the difference betwee...

AI Technical Summary

Problems solved by technology

[0005] The accuracy of existing vector modulation error analysis is not high

Since the measured signal is affected by various error factors, the reference signal cannot be recovered completely and accurately

[0006] Existing vector modulation error analysis methods are complex and slow

Restoration of the reference signal requires a lot of error correction calculations, and the calculation process is complicated, so it is difficult to improve the analysis speed

[0007] Can not reflect the vector modulation error of the DUT

The excitation signal applied to the DUT itself is not ideal, and the existing test methods cannot remove the influence of the vector modulation error of the excitation signal itself, so it cannot accurately reflect the characteristics of the DUT

Images