In one embodiment, an apparatus includes a baseband circuit to generate a plurality of subcarriers of a complex sample of a message to be transmitted, and a compensation circuit coupled to the baseband circuit, the compensation circuit to compensate for IQ mismatch. The compensation circuit may include: a calibration circuit to determine, using a tone signal, gain correction values and phase correction values for a subset of the plurality of subcarriers; and a correction circuit to apply the gain correction values and the phase correction values to the plurality of subcarriers to compensate for the IQ mismatch.

First and second communication devices shape symbol constellation in wireless transmissions. The first communication device obtains a second symbol constellation based on the first symbol constellation and the set of weights, where the first symbol constellation is based on a radiating pattern in a set of radiating patterns for the first communication device and the weights are derived based on the first symbol constellation. Thereafter, the set of antenna elements are controlled according to the radiating pattern for transmitting a set of information bits mapped onto the second symbol constellation. Thereby, the second symbol constellation is customized to the radio environment to enable smart radio that enjoys improved signal design and thereby better performance.

First and second communication devices shape symbol constellation in wireless transmissions. The first communication device obtains a second symbol constellation based on the first symbol constellation and the set of weights, where the first symbol constellation is based on a radiating pattern in a set of radiating patterns for the first communication device and the weights are derived based on the first symbol constellation. Thereafter, the set of antenna elements are controlled according to the radiating pattern for transmitting a set of information bits mapped onto the second symbol constellation. Thereby, the second symbol constellation is customized to the radio environment to enable smart radio that enjoys improved signal design and thereby better performance.

Methods and systems are presented for correcting interference to audio transmissions containing data. In one embodiment, a method is presented that includes receiving an audio transmission that includes data modulated onto an audio carrier signal. A first portion of the audio transmission may be detected that includes predetermined frequencies that are produced at predetermined times. The method may further include determining a frequency distribution for the predetermined frequencies and identifying magnitudes of the predetermined frequencies within the frequency distribution. A second portion of the audio transmission may then be equalized according to the magnitudes of the predetermined frequencies.

Embodiments of systems and methods for modulating a downlink signals representative of a communication signal are provided herein. An example method comprises receiving an input signal; in a first one or more processing blocks in a one or more processors, performing a first modulation operation on first data packets of the input signal based on a modulation scheme for a receiver of the downlink signal; in a second one or more processing blocks in the one or more processors in parallel with the first one or more processing blocks, performing a second modulation operation on second data packets of the input signal based on the modulation scheme; and generating a waveform as the downlink signal based on performing the first and second modulation operations.

The present invention concerns a real-time method for the blind demodulation of digital telecommunication signals, based on the observation of a sampled version of this signal. The method comprises the following steps: —acquisition, by a sampling, of a first plurality of signals in order to each constitute an input of a network of L processing blocks (G, F, H), also referred to here as “specialized neurons”, each neuron being simulated by the outputs of the preceding block, the first plurality of signals being input into the first block simulating a first neuron of the network in order to generate a plurality of outputs of the first block; each neuron F being simulated by the outputs of an upstream chain G and stimulating a downstream chain H; each set of samples passes through the same processing chain; —the outputs of the last blocks of the network ideally correspond to the demodulated symbols; —addition of a nonlinearity to each of the outputs of the last block of the network making it possible to calculate an error signal and propagation of this error in the reverse direction of the processing chain (“retropropagation”); —estimation, upon receipt of the error by each neuron (i), of a corrective term δθ.sub.i and updating, in each block, of the value of the parameter θ.sub.i according to θ.sub.i+=δθ.sub.i.

The present invention concerns a real-time method for the blind demodulation of digital telecommunication signals, based on the observation of a sampled version of this signal. The method comprises the following steps: —acquisition, by a sampling, of a first plurality of signals in order to each constitute an input of a network of L processing blocks (G, F, H), also referred to here as “specialized neurons”, each neuron being simulated by the outputs of the preceding block, the first plurality of signals being input into the first block simulating a first neuron of the network in order to generate a plurality of outputs of the first block; each neuron F being simulated by the outputs of an upstream chain G and stimulating a downstream chain H; each set of samples passes through the same processing chain; —the outputs of the last blocks of the network ideally correspond to the demodulated symbols; —addition of a nonlinearity to each of the outputs of the last block of the network making it possible to calculate an error signal and propagation of this error in the reverse direction of the processing chain (“retropropagation”); —estimation, upon receipt of the error by each neuron (i), of a corrective term δθ.sub.i and updating, in each block, of the value of the parameter θ.sub.i according to θ.sub.i+=δθ.sub.i.

An in-phase and quadrature mismatch compensator for a quadrature transmitter includes a delay element, a complex-valued filter and an adder. The delay element receives an input transmit signal and outputs a delayed transmit signal. The complex-valued filter receives the input transmit signal and outputs a selected part of a filtered output transmit signal. The adder adds the delayed transmit signal and the selected part of the filtered output transmit signal and outputs a pre-compensated transmit signal. In one embodiment, the selected part of the filtered output transmit signal includes the real part of the complex-valued output transmit signal. In another embodiment, the selected part of the filtered output transmit signal includes the imaginary part of the complex-valued output transmit signal. Two transmit real-valued compensators are also disclosed that combine the in-phase and quadrature signals before being filtered.

Disclosed are short-form demodulation reference signals configured to indicate certain modulation levels of a modulation scheme, from which a receiver can measure phase noise and amplitude noise in 5G/6G. A key feature of short-form demodulation references is resource efficiency. Examples include a demodulation reference occupying just one resource element, while providing the information needed to determine all of the modulation states of the modulation scheme, as well as the current noise factors. In one embodiment, the short-form demodulation reference may include two component signals with orthogonal phase, both being amplitude modulated by the transmitter according to a maximum amplitude level. The receiver can determine the phase noise from a ratio of the two received signal amplitudes, and the amplitude noise from the magnitude of the received waveform, thereby mitigating both amplitude noise and phase noise. The short-form demodulation reference can be added to each message for real-time noise mitigation.

Disclosed are short-form demodulation reference signals configured to indicate certain modulation levels of a modulation scheme, from which a receiver can measure phase noise and amplitude noise in 5G/6G. A key feature of short-form demodulation references is resource efficiency. Examples include a demodulation reference occupying just one resource element, while providing the information needed to determine all of the modulation states of the modulation scheme, as well as the current noise factors. In one embodiment, the short-form demodulation reference may include two component signals with orthogonal phase, both being amplitude modulated by the transmitter according to a maximum amplitude level. The receiver can determine the phase noise from a ratio of the two received signal amplitudes, and the amplitude noise from the magnitude of the received waveform, thereby mitigating both amplitude noise and phase noise. The short-form demodulation reference can be added to each message for real-time noise mitigation.