All-digital blind adaptive receiver for non-cooperative communications and signal exploitation

A digital signal processor comprising:

• a signal modeling circuit to model a digitally-modulated radio frequency (RF) communication stream using a set of incoming samples of the stream collected from a single antenna, the stream including a first signal, the first signal comprising a sequence of first digital symbols including a previous symbol and a current symbol, each first digital symbol being chosen from a plurality of first possible values, the first signal being modulated by a first known RF communication protocol having unknown time-varying parameters, the parameters having estimated previous values from modeling the previous symbol using a previous interval of the samples corresponding to the previous symbol;
• a sample collecting circuit to collect a current interval of the samples, the current interval beginning after an end of the previous interval and corresponding to the current symbol;
• a parameter predicting circuit to predict an end of the current interval and current values of the parameters based on the estimated previous values of the parameters;
• a symbol deciding circuit to decide a value of the current symbol using maximum likelihood estimation based on the first possible values, the predicted current values of the parameters, and a subset of the collected current interval of the samples;
• and
• a parameter estimating circuit to estimate the current values of the parameters using maximum likelihood estimation based on the decided value of the current symbol, the collected current interval of the samples, and the predicted current values of the parameters.

A digital receiver comprising:

• a radio frequency (RF) front end to receive analog RF signals of a digitally-modulated RF communication stream from a single antenna, the stream including a first signal, the first signal comprising a sequence of first digital symbols including a previous symbol and a current symbol, each first digital symbol being chosen from a plurality of first possible values, the first signal being modulated by a first known RF communication protocol having unknown time-varying parameters;
• an intermediate frequency (IF) front end to convert the received analog RF signals to analog intermediate frequency (IF) signals;
• an analog-to-digital converter (ADC) to convert the analog IF signals to a set of incoming samples of the stream;
• and
• a digital signal processor including
• a signal modeling circuit to model the communication stream using the set of incoming samples, the parameters having previous estimated values from modeling the previous symbol using a previous interval of the samples corresponding to the previous symbol,
• a sample collecting circuit to collect a current interval of the samples, the current interval beginning after an end of the previous interval and corresponding to the current symbol,
• a parameter predicting circuit to predict an end of the current interval and current values of the parameters based on the estimated previous values of the parameters,
• a symbol deciding circuit to decide a value of the current symbol using maximum likelihood estimation based on the first possible values, the predicted current values of the parameters, and a subset of the collected current interval of the samples, and
• a parameter estimating circuit to estimate the current values of the parameters using maximum likelihood estimation based on the decided value of the current symbol, the collected current interval of the samples, and the predicted current values of the parameters.