Receiver for a digital radiomobile system with cancellation of isofrequency interfering signals having the same kind of modulation, and relevant method

A method for the cancellation of an isofrequency interfering signal having the same modulation of a transmitted signal in a phase modulated burst mode transmission system, each burst including a known preamble, both the isofrequency interfering signal and the transmitted signal being received in a received signal the method comprising:

• demodulating the received signal;
• sampling the demodulated received signal at a frequency multiple of the bit transmission frequency, producing samples;
• estimating amplitude, phase and synchronism parameters of the interfering signal;
• reconstructing the transmitted signal with a maximum likelihood estimation process employing said parameters.

A method for the cancellation of an isofrequency interfering signal having the same modulation of a transmitted signal in a phase modulated burst mode transmission system, each burst including a known preamble, both the isofrequency interfering signal and the transmitted signal being received in a received signal the method comprising:

• demodulating the received signal;
• sampling the demodulated received signal at a frequency multiple of the bit transmission frequency, producing samples;
• estimating amplitude, phase and synchronism parameters of the interfering signal;
• reconstructing the transmitted signal with a maximum likelihood estimation process employing said parameters;
• wherein said parameters are estimated as a function of the comparison between the received signal and a preliminary reconstruction of the transmitted signal.

A method for the cancellation of an isofrequency interfering signal having the same modulation of a transmitted signal in a phase modulated burst mode transmission system, each burst including a known preamble, both the isofrequency interfering signal and the transmitted signal being received in a received signal the method comprising:

• demodulating the received signal;
• sampling the demodulated received signal at a frequency multiple of the bit transmission frequency, producing samples;
• estimating amplitude, phase and synchronism parameters of the interfering signal;
• reconstructing the transmitted signal with a maximum likelihood estimation process employing said parameters;
• wherein the reconstruction of the transmitted signal is responsive to a channel response estimation of the received preamble.

An apparatus for the cancellation of an isofrequency interfering signal having the same modulation of a transmitted signal in a phase modulated burst mode transmission system, each burst including a known preamble, both the isofrequency interfering signal and the transmitted signal being received in a received signal, the apparatus comprising:

• a demodulator for demodulating the received signal;
• sampler for sampling the demodulated received signal at a frequency multiple of the bit transmission frequency, producing samples;
• means for estimating amplitude, phase and synchronism parameters of the interfering signal;
• means for reconstructing the transmitted signal with a maximum likelihood estimation process employing said parameters.

A filter, for removing an undesired signal from a received signal, to approximate a transmitted signal, comprising:

• a demodulator, demodulating the received signal;
• a sampler, sampling the demodulated signal;
• a first estimator, estimating a channel impulse response, having an input of the sampled demodulated signal, and outputting a channel impulse response;
• a second estimator, estimating an amplitude and a phase of the undersired signal on the basis of the channel impulse response and the sampled demodulated signal;
• an approximation circuit, approximating the transmitted signal as a function of the sampled demodulated signal, the amplitude of the undesired signal and the phase of the undesired signal.

A method for removing an undesired signal from a received signal, to approximate a transmitted signal, comprising the steps of:

• (a) demodulating the received signal;
• (b) sampling the demodulated signal;
• (c) estimating a channel impulse response as a function of the sampled demodulated signal;
• (d) estimating an amplitude and a phase of the undesired signal on the basis of the channel impulse response and the sampled demodulated signal;
• (e) approximating the transmitted signal as a function of the sampled demodulated signal, the amplitude of the undesired signal and the phase of the undesired signal.