An electronic envelope detection circuit includes an input signal detecting circuit having at least one MOS transistor configured to receive a radiofrequency input signal and to deliver an internal signal on the basis of the input signal. The biasing point of the at least one transistor is controlled by the input signal and a control signal. A processing circuit that is coupled to the input signal detecting circuit is configured to deliver a low-frequency output signal on the basis of the internal signal and further deliver the control signal on the basis of the output signal. In operation, the value of the control signal decreases when the average power of the input signal increases, and vice versa.

A demodulation unit for recovering a transmitted symbol from a received signal that has been modulated using an MDPSK modulation scheme is described. The demodulation unit is configured to, for a current time instant, derive a current sample of a phase signal indicative of a phase of the received signal. Furthermore, the demodulation unit is configured to determine a set of discrimination signals for the current sample of the phase signal, based on the current sample of the phase signal and based on one or more previous samples of the phase signal for one or more previous time instants. In addition, the demodulation unit is configured to determine the transmitted symbol for the current time instant based on the set of discrimination signals.

Techniques for wireless communications are described. A demodulation reference signal generated using user information and a noncoherent modulation technique may be communicated between wireless devices. A data sequence may be extracted from the demodulation reference signal based on demodulating the demodulation reference signal using the noncoherent modulation technique and decoding the demodulation reference signal. The data sequence may be used to reconstruct a version of the demodulation reference signal used to descramble a received version of the demodulation reference signal. The descrambled demodulation reference signal may be used to estimate a data channel between a transmitting device and a receiving device.

Methods, systems, and devices for wireless communications are described. A transmitting device may encode a set of bits to transmit to a receiving device based on a repetition factor. The transmitting device may map, based on the repetition factor, the set of encoded bits to a subset of subcarriers such as adjacent subcarriers of a set of subcarriers. The transmitting device may generate a signal including the set of encoded bits based on the mapping, and transmit the generated signal to the receiving device. The receiving device may receive a modulated signal from the transmitting device, and identify, based on a repetition factor, a subset of subcarriers including adjacent subcarriers of a set of subcarriers associated with the modulated signal. The receiving device may average the subset of subcarriers including the adjacent subcarriers, and demodulate the modulated signal in accordance with the averaged subset of subcarriers including the adjacent subcarriers.

A method for reducing noise in a modulated electrical signal having a carrier frequency, includes acquiring in the time domain the modulated signal so as to obtain a plurality of pieces of the modulated signal; calculating, by transformation in the frequency domain, a spectrum of each piece of the modulated signal, the spectrum including an upper sideband extending over a range of frequencies greater than the carrier frequency, and a lower sideband extending over a range of frequencies lower than the carrier frequency, the spectrum including first values belonging to the upper sideband and second values belonging to the lower sideband; calculating a power spectrum for each piece of the modulated signal from the first values of the upper sideband and the second values of the lower sideband of the spectrum of each piece of the modulated signal; calculating an average of the power spectra.

A radio receiver comprises a matched filter bank and a decision unit. The matched filter bank has a plurality of filter modules for generating correlation-strength data from a sampled radio signal, each filter module being configured to cross-correlate the sampled signal with data representing a respective filter sequence. The decision unit is configured to use the correlation-strength data to generate a sequence of decoded symbols from the sampled signal. The matched filter bank and/or decision unit are configured to determine the value of each symbol in the sequence in part based on the value of a respective earlier decoded symbol from the sequence of decoded symbols.

The present disclosure discloses an M-ary DCSK method based on chaotic shape-forming filtering. The method includes the following steps: at S1, parameters of a communication system are set; at S2, HP information and LP information to be sent in each time slot are prepared; at S3, the information to be sent is modulated; at S4, a chaotic carrier is generated through a chaotic shape-forming filter; at S5, a transmitted signal is prepared; at S6, down-carrier frequency and matched filter is performed to a received signal; at S7, the sampling of a maximum SNR point is performed to an output signal of a matched filter; at S8, the decision of high priority information bits is resumed; and at S9, the decision of low priority information bits is resumed.

A communication system comprises a transmitter and a receiver that communicate differential phase modulated data over a wireline channel pair. The transmitter encodes data symbols by generating first and second data signals with differentially phase shifted signal transitions with respect to one another. The receiver receives the first data signal and the second data signal and samples the first data signal based on a signal transition timing of the second data signal to generate a first output data symbol. The receiver furthermore samples the second data signal based on signal transition timing of the first data signal to generate a second output data symbol.

A user equipment (910) is provided for use in a cellular network. The user equipment includes a transceiver (1010), a processor (1020), and a memory (1030). The user equipment (910) is configured to determine, for a data transmission, a mapping form a demodulation reference signal (DMRS) to a PNT-RS. A DMRS resulting signal is generated from a subset of DMRS for a first resource element in a subcarrier. The DMRS resulting signal is copied from the first resource element to a second resource element assigned to the PNT-RS in the subcarrier. The data transmission is transmitted using the DMRS resulting signal and the PNT-RS.

Method for processing a sequence of digital signal samples comprising a first sub-sequence and a second sub-sequence, said method comprising: forming (106) a first block of samples comprising the first sub-sequence and a second block of samples comprising header samples followed by the second sub-sequence; demodulating (108) the first block of samples through a digital demodulator to produce a first block of symbols, and the second block of digital signal samples through a second digital demodulator to produce a second block of symbols, the second demodulator implementing a carrier synchronisation or symbol rate synchronisation starting with the header samples (E6-E9), which comprise samples in a number adapted in such a way that the synchronisation is effective before the second demodulator demodulates the second sub-sequence; and reconstructing (114) a sequence of symbols by concatenating the first symbol block with the second symbol block.