The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4.sup.th-Generation (4G) communication system such as Long Term Evolution (LTE). Provided is an operation method of a base station in a wireless communication system. The method comprises: receiving, from a terminal, at least one piece of information among channel quality information on a resource region allocated to the terminal and non-Gaussian information on a nulling region corresponding to the resource region; and determining a modulation order for the terminal, a code rate, a ratio of the resource region to the nulling region based on the channel quality information and the non-Gaussian information.

When transmitting signals from a plurality of base stations (broadcasting stations), the base stations include at least a first base station having a first antenna with a first polarization and a second base station having a second antenna with a second polarization that is different from the first polarization. Then, when the first base station transmits a signal from the first antenna having the first polarization, the second base station transmits the same signal as the first antenna of the first base station from a second antenna having the second polarization, at the same time.

A dual-mode signal transceiver includes a first transmitter circuit, a second transmitter circuit, and a receiver circuit. The first transmitter circuit is configured to operate in a first mode and configured to process a first input signal according to a first oscillating signal, in order to output a first output signal. The second transmitter circuit is configured to operate in a second mode and configured to process a second input signal according to a second oscillating signal, in order to output a second output signal, wherein a frequency of the second oscillating signal is not an integral multiple of a frequency of the first oscillating signal. The receiver circuit is configured to process an external signal associated with one of the first mode and the second mode according to the first oscillating signal, in order to read data associated with the external signal.

A dual-mode signal transceiver includes a first transmitter circuit, a second transmitter circuit, and a receiver circuit. The first transmitter circuit is configured to operate in a first mode and configured to process a first input signal according to a first oscillating signal, in order to output a first output signal. The second transmitter circuit is configured to operate in a second mode and configured to process a second input signal according to a second oscillating signal, in order to output a second output signal, wherein a frequency of the second oscillating signal is not an integral multiple of a frequency of the first oscillating signal. The receiver circuit is configured to process an external signal associated with one of the first mode and the second mode according to the first oscillating signal, in order to read data associated with the external signal.

A frequency modulation circuit [[110-1]] includes a VCO [[5]], a DIV [[19]], a MIX [[20]], a single-phase differential converter [[18]], and a signal processing circuit [[6]]. The signal processing circuit [[6]] performs differential arithmetic processing of an intermediate frequency signal with a program of a microcomputer according to a quadrature demodulation scheme and, thereafter, measures a frequency from phase information, performs n-th order polynomial (n is an integer equal to or larger than 2) approximation on time-frequency data of an IF signal output by a chirp modulation control voltage after inverse function correction, and performs modulation correction for correcting a time error.

A modem includes a modulator and a demodulator. The demodulator includes a direct current removing (DCR) circuit to transition between an acquisition mode, where the DCR circuit operates with a first loop gain; and a tracking mode, where the DCR circuit operates with a second loop gain. The second loop gain is smaller than the first loop gain, and the timing of the transition between the acquisition mode and tracking mode is programmable.

A radio frequency (RF) front end chip in a phased array antenna panel for transmitting a modulated circularly-polarized signal is disclosed. The RF front end chip includes an oscillator providing an angular speed modulation signal to a quadrature generation block, the quadrature generation block providing an in-phase signal and a quadrature signal based on the angular speed modulation signal, a first amplifier receiving the in-phase signal and a data signal, and providing a modulated horizontally-polarized signal, and a second amplifier receiving the quadrature signal and the data signal, and providing a modulated vertically-polarized signal, where a modulated circularly-polarized signal is generated based on the modulated horizontally-polarized signal and the modulated vertically-polarized signal. The angular speed modulation signal controls an angular speed of the modulated circularly-polarized signal. The data signal is encoded by the angular speed modulation signal.

Example radio frequency (RF) transmitters and associated methods are disclosed. One example RF transmitter includes an RF oscillator, a real-time clock (RTC) oscillator. and a control circuit. The control circuit is configured to determine whether a calibration of the RF oscillator is needed; electrically couple the RF oscillator to the RTC oscillator and initiate calibrating of the RF oscillator using the RTC oscillator when it is determined that the calibration is needed; and activate the RF oscillator to operate in an open-loop mode to generate an RF signal for data transmission. The calibration can be performed in a closed-loop mode before the data transmission or in an open-loop mode during the data transmission.

Provided is a technique that can generate a spread spectrum clock signal in all of an upper-spread mode, a down-spread mode, and a center-spread mode. A spread spectrum clock generator (2) spreads a spectrum of a signal with a predetermined carrier frequency to generate a spread spectrum clock signal under the control of a control unit (13). The control unit includes carrier frequency correction control means (13b). The carrier frequency correction control means shifts the predetermined carrier frequency to generate, from one spread mode, a spread spectrum clock signal of another pseudo spread mode.

A modem includes a modulator and a demodulator. The demodulator includes a direct current removing (DCR) circuit to transition between an acquisition mode, where the DCR circuit operates with a first loop gain; and a tracking mode, where the DCR circuit operates with a second loop gain. The second loop gain is smaller than the first loop gain, and the timing of the transition between the acquisition mode and tracking mode is programmable.