Patent ID: 7804887

Claim:
An ultra-narrow bandwidth digital RF communication system comprising: at lease one sensor designed and configured to acquire information, and generate a signal containing said information, at least one transmitter configured to transmit ultra-narrow bandwidth digital RF radio signals, wherein the transmitter is designed and configured to receive and process the sensor-generated signal, the RF radio signals comprise a sequence of message bits relating to the sensed conditions, having a data rate in the range of about 1-100 bits per second, resulting in a transmitter carrier frequency having an ultra-narrow frequency bandwidth in the range of 1-100 Hz, and the RF radio signals are subjected to interfering processes based upon channel conditions that could induce carrier frequency shifts and instabilities in the range of 2-1000 times larger than the message bandwidth, a receiver configured to receive the RF radio signals using a detection bandwidth of about the same width as the signal bandwidth, wherein the receiver is further configured to isolate the frequency band, centered on the carrier frequency, which will contain the transmitted signals, convert the signals to digital data, input the digital data into a digital signal processor to detect, track, extract and decode the message, wherein the digital signal processor is designed and configured to: generate a frequency-time spectrogram of the digital data, analyze the spectrogram using detection and tracking algorithms based upon dynamic programming theories, to detect message bits in the spectrogram and track a series of such bits to determine the frequency-time path of the message, extract the bits present in the spectrogram, based upon the detected bits and frequency-time path of the bit-series, and decode the message.