The present invention discloses a real-time normalization apparatus and method of the PGC demodulation in a sinusoidal phase modulation interferometer. An optical setup containing a measuring interferometer and a monitoring interferometer is constructed. An electro-optic phase modulator is placed in the common reference arm of the two interferometers. High-frequency sinusoidal wave modulation and low-frequency triangular wave modulation are applied to the electro-optic phase modulator at the same time. Sinusoidal modulation is used for generating phase carrier, and PGC demodulation is performed to obtain quadrature signals containing the phase information to be measured. Triangular wave modulation makes the quadrature signals change periodically. Ellipse fitting is performed on the Lissajous figure corresponding to the quadrature signals, and real-time normalization of the PGC demodulated quadrature signals is achieved. By calculating the variation of the phase difference between the two interference signals, the measured displacement is obtained, and nanometer scale displacement measurement is achieved.

Systems and methods for combining signals from multiple active wireless receivers are discussed herein. An exemplary system comprises a first downconverter, a phase comparator, a phase adjuster, and a second downconverter. The first downconverter may be configured to downconvert a received signal from a first antenna to an intermediate frequency to create an intermediate frequency signal. The phase comparator may be configured to mix the received signal and a downconverted signal to create a mixed signal, compare a phase of the mixed signal to a predetermined phase, and generate a phase control signal based on the comparison, the downconverted signal being associated with the received signal from the first antenna. The phase adjuster may be configured to alter the phase of the intermediate frequency signal based on the phase control signal. The second downconverter may be configured to downconvert the phase-shifted intermediate frequency signal to create an output signal.

A transmitter according to the present invention includes: a mapping unit that generates modulation symbols by modulating a transmission bit sequence; a DSTBC coding unit that generates coded symbols by performing differential space-time block coding on the modulation symbols; a code conversion unit that performs, on the coded symbols, a conversion process selected from among a plurality of conversion processes; and an antenna that transmits the coded symbols after the conversion process.

Systems and methods for combining signals from multiple active wireless receivers are discussed herein. An exemplary system comprises a first downconverter, a phase comparator, a phase adjuster, and a second downconverter. The first downconverter may be configured to downconvert a received signal from a first antenna to an intermediate frequency to create an intermediate frequency signal. The phase comparator may be configured to mix the received signal and a downconverted signal to create a mixed signal, compare a phase of the mixed signal to a predetermined phase, and generate a phase control signal based on the comparison, the downconverted signal being associated with the received signal from the first antenna. The phase adjuster may be configured to alter the phase of the intermediate frequency signal based on the phase control signal. The second downconverter may be configured to downconvert the phase-shifted intermediate frequency signal to create an output signal.

A wireless communication device includes a radio frequency antenna and a transceiver. The transceiver includes a receiver having a switching architecture configured to generate a plurality of output phases within a local oscillator period based on the filtered RF signal and a respective plurality of local oscillator signals. The plurality of output phases can be organized into at least K groups where K is an integer of four or greater, and each nth group of the K groups includes nth and (n+K)th output phases of the plurality of output phases. The receiver can difference the nth and (n+K)th output phases of each respective group of the K groups, resulting in gain-added output phases.

This application discloses a wireless communication method, a wireless communications apparatus, and a wireless communications system. An example wireless communication method includes: receiving, by a terminal, indication information of uplink data transmission from a base station; determining, by the terminal, a base sequence configuration of a reference signal sequence corresponding to the modulation scheme of the uplink data transmission, and generating a dedicated demodulation reference signal based on the determined base sequence configuration of the reference signal sequence, where the modulation scheme of the uplink data transmission is one of a plurality of modulation schemes supported by the terminal, the plurality of modulation schemes include at least /2 binary phase shift keying (BPSK), and a base sequence configuration of a reference signal sequence corresponding to the /2 BPSK is different from a base sequence configuration of a reference signal sequence corresponding to another modulation scheme in the plurality of modulation schemes.

This application discloses a wireless communication method, a wireless communications apparatus, and a wireless communications system. An example wireless communication method includes: receiving, by a terminal, indication information of uplink data transmission from a base station; determining, by the terminal, a base sequence configuration of a reference signal sequence corresponding to the modulation scheme of the uplink data transmission, and generating a dedicated demodulation reference signal based on the determined base sequence configuration of the reference signal sequence, where the modulation scheme of the uplink data transmission is one of a plurality of modulation schemes supported by the terminal, the plurality of modulation schemes include at least /2 binary phase shift keying (BPSK), and a base sequence configuration of a reference signal sequence corresponding to the /2 BPSK is different from a base sequence configuration of a reference signal sequence corresponding to another modulation scheme in the plurality of modulation schemes.

In some examples, a delay apparatus includes a controllable delay line comprising a plurality of delay elements selectively connected in a signal path to vary a delay of a signal passing through the delay line, and a controllable phase shifter comprising reflective loads adjustable to vary a phase shift applied to the signal.

A method and apparatus are provided for demodulating a wireless signal modulated by phase-shift keying. The signal comprises a plurality of symbols. The method includes: obtaining a first sequence of samples based on the signal; converting the first sequence of samples to a first sequence of frequency domain samples; selecting, as a decision variable, the sample that has the maximum magnitude among the first sequence of frequency domain samples; and identifying a symbol or a symbol-transition based on the decision variable.

The present invention discloses a real-time normalization apparatus and method of the PGC demodulation in a sinusoidal phase modulation interferometer. An optical setup containing a measuring interferometer and a monitoring interferometer is constructed. An electro-optic phase modulator is placed in the common reference arm of the two interferometers. High-frequency sinusoidal wave modulation and low-frequency triangular wave modulation are applied to the electro-optic phase modulator at the same time. Sinusoidal modulation is used for generating phase carrier, and PGC demodulation is performed to obtain quadrature signals containing the phase information to be measured. Triangular wave modulation makes the quadrature signals change periodically. Ellipse fitting is performed on the Lissajous figure corresponding to the quadrature signals, and real-time normalization of the PGC demodulated quadrature signals is achieved. By calculating the variation of the phase difference between the two interference signals, the measured displacement is obtained, and nanometer scale displacement measurement is achieved.