Methods and apparatus for implementing passive wideband phase shifters are described. The phase shifters exhibit good linearity over a wide range of frequencies. Furthermore at least some features are directed to allowing the phase shifters to be implemented in some embodiments in a relatively compact manner making such embodiments well suited for supporting arrays and/or other implementations where a large number of phase shifters are to be implemented in a relatively small chip area.

A circuit includes a polar transmitter to generate a radio frequency output from amplitude and phase signal components. The polar transmitter includes an amplifier to combine amplitude and phase signal components. A processor is coupled to the polar transmitter to provide the amplitude and phase signal components. The processor includes: a digital modulation circuit to generate a modulated digital signal including in-phase and quadrature signal components and a correction circuit to calculate and apply a complex digital offset for local oscillator feedthrough of the amplifier. The complex digital offset includes an in-phase offset correction factor and a quadrature offset correction factor.

Devices, systems and methods for a fifth generation (5G) or new radio (NR) system comprising multiplexing, by a gNodeB (gNB), a physical broadcast channel (PBCH) and an associated demodulation reference signal (DMRS) in a time division multiplexing (TDM) manner; and transmitting, by the gNB, the PBCH by employing a Discrete Fourier Transform-spread-orthogonal frequency-division multiplexing (DFT-s-OFDM) waveform and its associated DMRS.

An electronic control unit comprises circuitry to receive a combined signal via a vehicle bus of a vehicle, wherein the combined signal contains a combination of a data signal and a watermark signal, which can be a radio frequency (RF) signal or an analog baseband signal, wherein the data signal includes a message, circuitry to extract a watermark from the watermark signal, circuitry to verify the watermark based on a comparison of the watermark with a pre-defined watermark, circuitry to extract the data signal from the combined signal and obtain the message from the data signal, and circuitry to authenticate the message based on the verification of the watermark.

An electronic control unit comprises circuitry to receive a combined signal via a vehicle bus of a vehicle, wherein the combined signal contains a combination of a data signal and a watermark signal, which can be a radio frequency (RF) signal or an analog baseband signal, wherein the data signal includes a message, circuitry to extract a watermark from the watermark signal, circuitry to verify the watermark based on a comparison of the watermark with a pre-defined watermark, circuitry to extract the data signal from the combined signal and obtain the message from the data signal, and circuitry to authenticate the message based on the verification of the watermark.

A signal processing method is applied to an RFID electronic tag, and includes: coding a digital baseband signal to obtain a coded signal; performing phase-shift keying modulation on the coded signal to obtain a first modulated signal; performing OFDM modulation on the first modulated signal to obtain a second modulated signal; and sending the second modulated signal to an RFID reader, by means of which the OFDM demodulation, phase-shift keying demodulation, and decoding are performed sequentially on the second modulated signal. According to the signal processing method and device, and the RFID system of one or more embodiments of present disclosure, the RFID system can be caused to effectively utilize bandwidth, thereby achieving high-speed transmission of signals and significantly reducing a bit error ratio of signal transmission.

A method of reducing transmission power for an encoded data stream includes the steps of receiving an incoming data stream having equal probability for a plurality of incoming data bits, assigning a symbol scheme to the received data bits of the incoming data stream according to probabilities of occurrence of individual ones of the received data bits, and transmitting an outgoing data stream according to the assigned symbol scheme having a second average transmit power, different than the first average transmit power, for a plurality of outgoing symbols.

A method of reducing transmission power for an encoded data stream includes the steps of receiving an incoming data stream having equal probability for a plurality of incoming data bits, assigning a symbol scheme to the received data bits of the incoming data stream according to probabilities of occurrence of individual ones of the received data bits, and transmitting an outgoing data stream according to the assigned symbol scheme having a second average transmit power, different than the first average transmit power, for a plurality of outgoing symbols.

Example reference signal transmission methods and apparatus are described. One example method includes that a first node maps a reference signal to a first transmission resource and sends the reference signal. The first transmission resource is included in a second transmission resource used by the first node to send data, and the second transmission resource includes a first symbol and at least one subcarrier corresponding to the first symbol. The first transmission resource includes at least one of an M.sup.th subcarrier or an N.sup.th-to-last subcarrier in the at least one subcarrier corresponding to the first symbol, and M and N are preset, specified in a protocol, or configured. The reference signal is used to determine phase information of a channel.

A transmission apparatus that (i) generates a Quadrature Phase Shift Keying (QPSK) modulation signal s1(t) by applying a QPSK modulation scheme to a first data sequence, (ii) generates a 16-Quadrature Amplitude Modulation (QAM) modulation signal s2(t) by applying a 16-QAM modulation scheme to a second data sequence, (iii) generates a transmission signal z1(t) and a second transmission signal z2(t) by applying a phase hopping process, a precoding process, and a power adjust process to the QPSK modulation signal s1(t) and the 16-QAM modulation signal s2(t), wherein an average transmission power of the 16-QAM modulation signal s2(t) being the same as an average transmission power of the QPSK modulation signal s1(t), and (iv) transmits the transmission signal z1(t) from a first antenna at a first time and a first frequency and the second transmission signal z2(t) from a second antenna at the first time and the first frequency.