H04L27/2331

ERROR RETRO-PROPAGATION FOR A CHAIN FOR THE BLIND DEMODULATION OF A DIGITAL TELECOMMUNICATION SIGNAL
20200328921 · 2020-10-15 ·

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 .sub.i and updating, in each block, of the value of the parameter .sub.i according to .sub.i+=.sub.i.

Demodulator for pulse-width modulated clock signals

A demodulator for pulse-width modulated clock signals is disclosed. In one aspect, the demodulator includes an edge detector configured to detect transitions in a reference clock and output a signal indicative of timing of the detected transitions. The demodulator may also include a modulation detection circuit configured to identify modulation events of at least one pulse-width modulated pulse in the reference clock based on the signal output from the edge detector and output a signal indicative of the at least one pulse-width modulated pulse modulation event being identified. The demodulator may further include a retiming circuit configured to generate an output clock synchronized with the at least one pulse-width modulated pulse modulation event based on the signal output from the modulation detection circuit.

METHOD AND APPARATUS FOR TRANSMITTING PLCP FRAME IN WIRELESS LOCAL AREA NETWORK SYSTEM

A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIG field.

Physiological information collecting system and transceiver device thereof

A physiological information collecting system and a transceiver device thereof are configured to collect physiological information from animal bodies. The transceiver device includes a front-end circuit, a follower circuit, a quadrature delay line and an output circuit. The front-end circuit separates a discontinuous signal into an in-phase signal and a quadrature signal. The follower circuit outputs a control voltage and rotates the in-phase signal by a predetermined phase angle to output a follower signal. The quadrature delay line rotates the quadrature signal by a corresponding phase angle according to the control voltage. The output circuit synthesizes the follower signal and the quadrature signal and outputs a data signal by demodulating the discontinuous signal. Consequently, the transceiver device reduces the bandwidth range of the discontinuous signal when receiving the discontinuous signal, reduces the power consumed by the transceiver device, and demodulates the discontinuous signal with various transmission rates of different data.

Method and apparatus for transmitting PLCP frame in wireless local area network system

A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIG field.

Methods and apparatus of adjusting delays of signals

In some examples, a delay apparatus includes a controllable delay line comprising a plurality of delay elements selectively connected in a signal path to vary a delay of a signal passing through the delay line, and a controllable phase shifter comprising reflective loads adjustable to vary a phase shift applied to the signal.

Method and apparatus for transmitting PLCP frame in wireless local area network system

A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIG field.

Wakeup radio transmit diversity

Methods, systems, and devices for wireless communication are described. A transmitting device may transmit a wakeup message to another device. The wakeup message may be transmitted using a transmit diversity scheme in accordance with aspects of the present disclosure. The transmit diversity may, for example, include a cyclic shift diversity scheme, a phase rotation scheme, a symbol generation scheme, or combinations thereof. The transmit diversity may in some cases improve a communication range of the wakeup message or otherwise benefit the wireless communications system.

Method and Apparatus for Transmitting PLCP Frame in Wireless Local Area Network System

A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIGfield.

Frequency offset estimation
11962443 · 2024-04-16 · ·

A receiver comprises a matched filter bank, decision logic and a frequency offset estimator. The matched filter bank comprises an input for receiving data representative of a frequency- or phase-modulated signal. The decision logic generates a sequence of demodulated symbol values from outputs of the matched filter bank. The frequency offset estimator determines a first phase value from a first output and a second phase value from a second output of the matched filter bank, the second output being offset from the first by L symbol periods. It also determines a phase adjustment value from an L-symbol subsequence within the sequence of demodulated symbol values, each subsequence value being determined from values output by the matched filter bank between the first and second outputs. It estimates a frequency offset based on the difference between the first phase value plus the phase adjustment value, and the second phase value.