Client data bits, including first client data bits and second client data bits, are communicated from a transmitter to a receiver. At the transmitter, the first client data bits are processed to generate processed values, where each processed value is more likely to be a first element than a second element. Forward Error Correction FEC encoding is applied to the second client data bits to generate FEC-encoded values. Symbols are created by mapping the FEC-encoded values to first positions in the symbols and by mapping the processed values to second positions in the symbols. The symbols are modulated onto a communications channel using a modulation scheme with a code that assigns a lower average energy to symbols containing the first elements in the second positions than to symbols containing the second elements in the second positions. At the receiver, client data bits are decoded using conditional chain decoding.

A quadrature detection unit subjects an FM signal to quadrature detection using a local oscillation signal and outputs a base band signal. A first correction unit and a second correction unit correct the base band signal using a DC offset correction value. A DC offset detection unit subjects the corrected base band signal to rectangular to polar conversion and derives the DC offset correction value such that amplitudes in a plurality of phase domains defined in an IQ plane approximate each other. An FM detection unit subjects the corrected base band signal to FM detection and generates a detection signal. An addition unit adds an offset to the detection signal. An AFC unit generates a control signal for controlling a frequency of a local oscillation signal based on the detection signal to which the offset is added.

A novel and useful apparatus and method for an image-interferer aware single quadrature RF downconversion (SQRD) low intermediate frequency (LIF) receiver and related power reduction techniques utilized therein. The invention applies zero-margin adaptive transceiver (ZMAT) design principles to considerably reduce the receiver's power consumption in an adaptive fashion in accordance with the instantaneous reception conditions. In a low IF dual-branch (i.e. quadrature) downconversion receiver, the radio monitors the image strength and shuts off the receiver's Q branch (or I branch) when image rejection is not needed (i.e. when the relative image strength is below a threshold), thus significantly reducing power consumption in the RF receiver. A zero IF receiver is switched to a SQRD low IF receiver of lower power consumption when the image interferer strength is low enough to allow for a given required level of performance.

A novel and useful apparatus and method for an image-interferer aware single quadrature RF downconversion (SQRD) low intermediate frequency (LIF) receiver and related power reduction techniques utilized therein. The invention applies zero-margin adaptive transceiver (ZMAT) design principles to considerably reduce the receiver's power consumption in an adaptive fashion in accordance with the instantaneous reception conditions. In a low IF dual-branch (i.e. quadrature) downconversion receiver, the radio monitors the image strength and shuts off the receiver's Q branch (or I branch) when image rejection is not needed (i.e. when the relative image strength is below a threshold), thus significantly reducing power consumption in the RF receiver. A zero IF receiver is switched to a SQRD low IF receiver of lower power consumption when the image interferer strength is low enough to allow for a given required level of performance.

A method to receive telemetry messages over an RF channel, the method implemented by a system on a chip, in which a signal is received from the output of an input RF module, the received signal is offset in time and frequency wherein the signal, at first, is offset in time so that the offset magnitudes uniformly fill the length of one data bit, then, the signal is offset in frequency so that the offset magnitudes uniformly fill the space between the Fourier transform subcarriers, with the frequency offsets being independent of the time offsets; each signal processed at the preceding step is subjected to sequential Fourier transforms, with the first time element of each next transform immediately following the last element of the preceding transform; all messages are demodulated independently. The technical result consists in that messages can be received over multiple channels at multiple rates.

An appropriate synthesized signal cannot be obtained by only correcting relative phase errors of a plurality of received signals; therefore, a received signal processor according to an exemplary aspect of the present invention includes a plurality of signal-to-noise ratio estimation means for estimating respective signal-to-noise ratios of a plurality of digital signal sequences in which relative phase errors of a plurality of received signal sequences having been corrected; a plurality of temporary decision means for performing symbol decisions of the plurality of digital signal sequences and outputting symbol signal sequences; symbol-map-rotation determination means for determining respective phase rotation amounts of the plurality of digital signal sequences from the plurality of symbol signal sequences and the respective signal-to-noise ratios of the plurality of digital signal sequences; and a plurality of phase rotation means for rotating phases of the plurality of digital signal sequences respectively based on the phase rotation amounts.

A robust frequency drift tracking receiver. The received signal is translated to an intermediate frequency in the RF stage by a quadrature demodulator, and is then brought into the base band by a digital mixer made by a CORDIC. A base band processing stage allows for a synchronization of the receiver relative to the data frame, to estimate data and to output a counter-reaction signal to the CORDIC, obtained by integration of successive frequency corrections, with a predetermined step.

A measuring device in which a non-electrical variable is converted into an electrical measurement signal via an electrical alternating current having a frequency, wherein the measurement signal contains a signal portion dependent on the non-electrical variable and is double the frequency, and a fault signal portion dependent on the alternating current and is at the frequency, where the measurement signal is pre-processed and digitized to generate a digital signal that is detected and processed to generate a measured value proportional to the non-electrical variable and to generate a fault signal value, wherein the fault signal value is utilized to normalize the measured value that is normalized in a normalizing stage, by forming the quotient using the square of the fault signal value, and is output as a normalized measured value.

A robust frequency drift tracking receiver. The received signal is translated to an intermediate frequency in the RF stage by a quadrature demodulator, and is then brought into the base band by a digital mixer made by a CORDIC. A base band processing, stage allows for a synchronisation of the receiver relative to the data frame, to estimate data and to output a counter-reaction signal to the CORDIC, obtained by integration of successive frequency corrections with a predetermined step.

An apparatus for detecting the end of a communication is disclosed. The apparatus includes an interface circuit for receiving an encoded signal and a carrier signal recovery circuit coupled to an output of the interface circuit. The carrier signal recovery circuit is configured to output a carrier signal of the encoded signal and a second signal that is out of phase with the carrier signal. The apparatus also includes a decoding circuit configured to decode the encoded signal as a function of both the encoded signal and the carrier signal output by the carrier signal recovery circuit. The apparatus also includes a detection circuit configured to detect an indication of an end of a communication in the encoded signal as a function of both the encoded signal and the second signal.