In a modulation correction method, an adjusted amplitude is determined based on an amplitude between adjacent zero crossings of a modulated signal, the adjacent zero crossings are shifted to determine shifted zero crossings, and the modulated signal is adapted based on the adjusted amplitude and the shifted zero crossings to generate a corrected modulated signal corresponding to the modulated signal.

A wideband, linear, direct-digital RF modulator (DDRM) for a digitally-intensive transmitter (DTX) includes an interpolation filter and an in-phase/quadrature (I/Q)-interleaving RF digital-to-analog converter (RF-DAC). The interpolation filter suppresses sampling replicas in the DDRM's output RF spectrum. I/Q interleaving performed by the interleaving RF-DAC avoids problems associated with using two separate I- and Q-path RF-DACs. Each unit cell of the interleaving RF-DAC is capable of producing four unique non-overlapping waveforms covering all four quadrants of the I/Q signal plane. In one embodiment of the invention, the interleaving RF-DAC includes three parallel-connected RF-DACs operating in accordance with a multi-phase set of LO clocks to both cancel 3.sup.rd-order and 5.sup.th-order LO harmonics generated by the RF-DAC unit cells' interleaving logic and prevent 3.sup.rd-order intermodulation from occurring in the DTX's final stage RF power amplifier.

A method of transmitting, by a transmitting device, an orthogonal frequency division multiplexing (OFDM) signal in a wireless communication system, the method including: generating, by a digital module of the transmitting device, a frequency-shifted OFDM baseband signal by performing frequency up-shift of a first signal by a difference between a carrier frequency and a first frequency , wherein the first frequency is, among frequencies corresponding to integer multiples of 128; closest to the carrier frequency , and wherein is an OFDM subcarrier spacing; up-converting, by an analog oscillator of the transmitting device, the frequency-shifted OFDM baseband signal by the first frequency to generate an OFDM symbol signal at the carrier frequency fo; and transmitting the OFDM symbol signal at the carrier frequency .

A system includes mode division multiplexing (MDM) processing circuitry for applying an orbital angular momentum (OAM) to each of a first group of a plurality of input signals and multiplexing the OAM processed signals together. Second processing circuitry performs wavelength distribution multiplexing (WDM) on a second group of the plurality of input signals, wherein the WDM processed signals and the MDM processed signals are orthogonal to one another. Combining circuitry combines the WDM processed signals and the MDM processed signals. Polarization processing circuitry adds polarization to at least one of the WDM processed signals, and the MDM processed signals and a transmitter transmits the combine and polarized processed signal over a link.

Disclosed is a method for communication by a base station in a wireless communication system, including transmitting, to a user equipment (UE), downlink control information (DCI) including information on a modulation and coding scheme (MCS) for processing downlink data using an MCS table among a plurality of tables, and transmitting, to the UE, the downlink data, wherein each of the plurality of MCS tables indicates modulation orders and code rates, wherein the plurality of MCS tables comprises a first MCS table which supports 256 quadrature amplitude modulation (QAM) and a second MCS table which does not support 256 QAM, and wherein a number of MCS indexes in the first MCS table is equal to a number of MCS indexes in the second MCS table.

An apparatus and method for testing an upstream path of a cable network are disclosed. The upstream path is tested by capturing and analyzing upstream data packets generated by a specific terminal device. A test instrument is connected at a node of the cable network. The test instrument establishes a communication session with the headend, informing the headend of an identifier of the device that will generate the test upstream data packet. The test upstream data packet is captured and analyzed at the headend, so that the results of the analysis can be communicated back to the test instrument. To speed up the packet capturing and filtering process, the upstream data packets can be pre-filtered based on packet duration and/or arrival time.

A method of recovering information encoded by a modulated sinusoidal waveform having first, second, third and fourth data notches at respective phase angles, where a power of the modulated sinusoidal waveform is reduced relative to a power of an unmodulated sinusoidal waveform within selected ones of the first, second, third and fourth data notches so as to encode input digital data. The method includes receiving the modulated sinusoidal waveform and generating digital values representing the modulated sinusoidal waveform. A digital representation of the unmodulated sinusoidal waveform is subtracted from the digital values in order to generate a received digital data sequence, which includes digital data notch values representative of the amplitude of the modulated sinusoidal waveform within the first, second, third and fourth data notches. The input digital data is then estimated based upon the digital data notch values.

The equalizer has a first differential pair having a first transistor and a second transistor and a second differential pair having a third transistor and a fourth transistor. A first terminal of the first transistor and a first terminal of the third transistor are connected to each other, and a first terminal of the second transistor and a first terminal of the fourth transistor are connected to each other, so that the first differential pair and the second differential pair have common input terminals. Also, resistors are respectively connected to second terminals of the first, second, third, and fourth transistors, a first zero point generation circuit is connected between the second terminal of the first transistor and the second terminal of the second transistor, and a second zero point generation circuit is connected between the second terminal of the third transistor and the second terminal of the fourth transistor.

A wireless transceiver. The transceiver includes: (i) a transmit signal path; (ii) a calibration path, comprising a conductor to connect a calibration tone into the transmit signal path; (iii) a receive signal path, comprising a first data signal path to process a first data and a second data signal path, different than the first data signal path, to process a second data; (iv) a first capacitive coupling to couple a response to the calibration tone from the transmit signal path to the first data signal path; and (v) a second capacitive coupling to couple a response to the calibration tone from the transmit signal path to the second data signal path.

A system, method, and electronic device for compensating in-phase (I) and quadrature (Q) mismatch (IQMM) are herein disclosed. The system includes an IQ mismatch compensator (IQMC) configured to compensate for IQMM between a time-domain I signal and a time-domain Q signal using filter weight coefficients, and output a compensated I signal and a compensated Q signal, a fast Fourier transformation (FFT) circuit configured to perform an FFT on the compensated I signal and the compensated Q signal to a frequency-domain compensated signal, and a coefficient updater configured to update the filter weight coefficients based on a frequency-domain observation of the frequency-domain compensated signal.