Improved methods and apparatus for demodulating digital wireless signals, wireless digital networks, local area networks, and phase modulated wireless local area networks

摘要

The transmitter's phase shift modulator has only a control input that is connected to a binary signal source. The high frequency carrier signal is provided to the carrier signal input of the modulator. The modulated carrier signal is transmitted to a receiver that is added with a local oscillator frequency. At the receiver, a limit amplifier amplifies the modulated signal so that the received signal is formed into a sinusoidal pulse with a uniform height. The demodulator detects when the space between the edges of the sinusoidal signal fluctuates in response to the phase shift modulation of the transmitter. If the space between edges of the sinusoidal IF signal is detected to be shorter than a normal space in a normal IF signal that is not modulated, a first binary value appears. If the space between edges of the sinusoidal IF signal is longer than the normal space for the unmodulated normal IF signal, a second binary value appears. The frequency drift compensation circuit is configured to block frequency fluctuations of the carrier and local generator.