Non-coherent quadrature demodulation of MSK signals

In a receiver a method for recovering a signal comprising the steps of:

• receiving a carrier signal which is MSK modulated with a bit stream of a digital information signal having its alternate bits complemented via a pre-coder;
• quadrature demodulating the received carrier signal for providing a pair of quadrature demodulated signals;
• and
• EXORing the pair of quadrature demodulated signals for recovering the bit stream of the digital information signal.

A communication system comprising:

• transmitter means for transmitting a carrier signal modulated with a digital information signal having a bit stream, comprising:
• a pre-coder for complementing alternate bits of the bit stream of the digital information signal;
• a MSK (minimum shift keying) modulator;
• at least one receiver, including:
• a receiver for receiving the carrier signal to produce a received signal;
• a quadrature demodulator for demodulating the received signal to produce a pair of baseband quadrature demodulated signals;
• and
• means for EXORing the pair of baseband quadrature demodulated signals for recovering the bit stream of the digital information signal.