Patent classifications
H04L27/2331
ULTRA LOW POWER WIDEBAND NON-COHERENT BINARY PHASE SHIFT KEYING DEMODULATOR USING FIRST ORDER SIDEBAND FILTERS WITH PHASE ZERO ALIGNMENT
An embodiment of the present invention relates to an ultra low power wideband asynchronous binary phase shift keying (BPSK) demodulation method and a circuit configuration thereof. The ultra low power wideband asynchronous BPSK demodulation circuit comprises a sideband division and upper sideband signal delay unit dividing a modulated signal into an upper sideband and a lower sideband by a first order high-pass filter and a first order low-pass filter; a data demodulation unit latching, through a hysteresis circuit, a signal generated by a difference between the analog signals in which a phase difference between the delayed upper sideband analog signal and the lower sideband analog signal is aligned at 0, so as to demodulate digital data; and a data clock recovery unit for generating a data clock by using a signal digitalized from the lower sideband analog signal through a comparator and a data signal.
Robust coherent and self-coherent signal processing techniques
A receiver that may include a receiver front end arranged to receive (a) a received signal, (b) a reference signal generated by a local oscillator laser, and to output a first intermediate signal; a carrier phase estimator that is arranged to receive the first intermediate signal and to generate a phase estimation signal that represents a phase difference between the received signal and the reference signal; wherein the carrier phase estimator comprises a multi-symbol-differential-detection module and a carrier phase demodulator; and an output circuit arranged to receive the phase estimation signal and to apply a slicing operation to provide an output signal of the carrier phase estimator.
PLC FCH unitary circle differential symbol and preamble encoding determination
Embodiments of the invention provide a method for discriminating between two types of encoding schemes for the frame control header (FCH) used in G3-type narrow band OFDM communications. The two modes for encoding are Differential with respect to the previous Symbol (DS) and Differential with respect to the Preamble (DP). This mode is sometimes referred to as coherent mode.
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.
SYSTEM AND METHOD FOR BLIND CHANNEL ESTIMATION AND COHERENT DIFFERENTIAL EQUALIZATION IN AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) RECEIVER
In one aspect, an apparatus includes: a fast Fourier transform (FFT) engine to receive and convert a plurality of orthogonal frequency division multiplexing (OFDM) samples into a plurality of frequency carriers; a detector coupled to the FFT engine to determine a channel estimate for a first frequency carrier using a first channel estimate for the first frequency carrier and a plurality of other channel estimates, each of the plurality of other channel estimates for one of a plurality of neighboring frequency carriers within an evaluation window, and determine a log likelihood ratio (LLR) for the first frequency carrier using the channel estimate for the first frequency carrier; and a decoder coupled to the detector to decode a first OFDM symbol comprising the first frequency carrier using the LLR for the first frequency carrier.
Data carrier apparatus, communication system, and replaceable unit
In a data carrier apparatus, a reception unit receives, from a data carrier driving apparatus, a pulse signal that alternatingly repeats a first-level period and a second-level period, which are set based on individual data values. A measurement unit measures respective time widths of the first-level period and the second-level period in the received pulse signal. A demodulation unit demodulates data conveyed by the received pulse signal, by determining the data value corresponding to the first-level period based on a measured value of the first-level period output from the measurement unit and a first reference value, and determining the data value corresponding to the second-level period based on a measured value of the second-level period output from the measurement unit and a second reference value.
DEMODULATION
A receiver device comprises receiving circuitry configured to receive a radio signal modulated using frequency shift keying or phase shift keying, the radio signal comprising a plurality of successive symbol intervals, differential detector circuitry configured to multiply a signal for a current symbol interval with a first reference signal and output a first output signal for the current symbol interval, wherein the first reference signal corresponds to a conjugate of a signal for a first symbol interval preceding the current symbol interval and multiply the signal for the current symbol interval with a second reference signal and output a second output signal for the current symbol interval, wherein the second reference signal corresponds to a conjugate of a signal for a second symbol interval preceding the first symbol interval, in which the conjugate of the signal for the second symbol interval has been phase adjusted in dependence on a previous phase decision for the first symbol interval preceding the current symbol interval, combining circuitry configured to combine the first output signal for the current symbol interval and the second output signal for the current symbol interval to obtain a combined signal for the current symbol interval, and decision circuitry configured to output a phase decision for the current symbol interval in dependence upon the combined signal.