An apparatus for wireless communication is disclosed that performs zero-crossing-avoidance encoding for quadrature amplitude modulation. In an example aspect, the apparatus includes a polar transceiver configured to be coupled to an antenna. The polar transceiver is configured to transmit, via the antenna, data including multiple symbols associated with quadrature amplitude modulation. The multiple symbols include multiple sets of two consecutive symbols. An absolute value of a phase difference between the two consecutive symbols within each set of the multiple sets is substantially different than 180 degrees.

Methods, systems, and devices for wireless communications are described. A user equipment (UE), that is configured for demodulation reference signal (DMRS) bundling, may receive a control message that schedules first and second sets of repetitions of an uplink transmission. The UE may determine a phase coherency configuration to be applied for DMRS transmissions corresponding to each set of repetitions. The phase coherency configuration may be determined based on a phase coherency capability of the UE, and the phase coherency configuration may specify that phase coherency is to be maintained for one or more of the first set of repetitions separate from one or more of the second set of repetitions. The UE may transmit the first set of repetitions with a first set of demodulation reference signals and the second set of repetitions with a second set of demodulation reference signals in accordance with the phase coherency configuration.

A generating unit that generates phase difference-added first data obtained by adding a phase change according to second data to a first signal indicating first data and a transmitting unit that transmits the phase difference-added first data are provided, and thus the first data and the second data can be transmitted through a simple configuration.

A microprocessor includes a memory, an input/output port and a switch controller. Transmission data, a spread code and an inverted code are stored in the memory. The switch controller generates a spread spectrum signal by calling up either of the spread code or the inverted code in accordance with a bit of the transmission data. A switch connected to the input/output port is switched on and off based on the spread spectrum signal. In addition, an antenna is connected to the input/output port via a coupler. An oscillation circuit includes a reference oscillator and a BPF and inputs a harmonic of a reference signal to the coupler as a carrier wave.

A method for demodulating a signal is provided. The method includes: acquiring a reference clock signal provided by a power management unit (PMU) in a mobile terminal; determining a moving velocity of the mobile terminal; determining, based on the moving velocity, a Doppler frequency shift value generated when the mobile terminal receives a radio frequency (RF) signal transmitted by a base station; and demodulating, according to the reference clock signal and the Doppler frequency shift value, the received RF signal.

An apparatus for wireless communication is disclosed that performs zero-crossing-avoidance encoding for quadrature amplitude modulation. In an example aspect, the apparatus includes a polar transceiver configured to be coupled to an antenna. The polar transceiver is configured to transmit, via the antenna, data including multiple symbols associated with quadrature amplitude modulation. The multiple symbols include multiple sets of two consecutive symbols. An absolute value of a phase difference between the two consecutive symbols within each set of the multiple sets is substantially different than 180 degrees.