Amplitude noise, phase noise, and interference can be mitigated in 5G and 6G by exploiting advantages of two different modulation schemes. A message may be modulated according to a first modulation scheme, such as multiplexed amplitude and phase modulation, and then received (including noise and interference) according to a second modulation scheme, such as QAM (quadrature amplitude modulation). In addition, a compact demodulation reference can be transmitted wherein a first resource element exhibits a particular phase along with a maximum and a minimum branch amplitude, and a second resource element is blank. The receiver calibrates the amplitude levels according to the demodulation reference, calculates the phase noise according to a ratio of the two branch amplitudes, and measures the interference according to the unpowered (blank) second resource element. The receiver can then demodulate the message according to the second modulation scheme, while correcting for phase noise, fading, and interference.

Amplitude noise, phase noise, and interference can be mitigated in 5G and 6G by exploiting advantages of two different modulation schemes. A message may be modulated according to a first modulation scheme, such as multiplexed amplitude and phase modulation, and then received (including noise and interference) according to a second modulation scheme, such as QAM (quadrature amplitude modulation). In addition, a compact demodulation reference can be transmitted wherein a first resource element exhibits a particular phase along with a maximum and a minimum branch amplitude, and a second resource element is blank. The receiver calibrates the amplitude levels according to the demodulation reference, calculates the phase noise according to a ratio of the two branch amplitudes, and measures the interference according to the unpowered (blank) second resource element. The receiver can then demodulate the message according to the second modulation scheme, while correcting for phase noise, fading, and interference.

A reception device includes: a receiver that receives a multiplexed signal; a first demapper that demaps the multiplexed signal, with a second modulated symbol stream of a second data series being included in the multiplexed signal as an undefined signal component, to generate a first bit likelihood stream of a first data series; a second demapper that demaps the multiplexed signal, with a first modulated symbol stream of the first data series being included in the multiplexed signal as an undefined signal component, to generate a second bit likelihood stream of the second data series; a first decoder that performs error control decoding on the first bit likelihood stream to derive the first data series; and a second decoder that performs error control decoding on the second bit likelihood stream to derive the second data series.

A clock generation circuit has an injection-locked oscillator, a frequency doubler circuit, low pass filters and a calibration circuit. The injection-locked oscillator has an input coupled to a half-rate clock signal. The frequency doubler circuit has inputs coupled to outputs of the injection-locked oscillator. Each of the low pass filters has an input coupled to one of a plurality of outputs of the frequency doubler circuit. The calibration circuit includes comparison logic that receives outputs of the low pass filters. The calibration circuit has an output coupled to a control input of a source of a supply current in the injection-locked oscillator. In one example, the source of the supply current is a current digital to analog converter.

A method comprises: digitizing a signal to produce a reference frame of amplitude samples in a time-domain; generating a spectrogram that includes energy content of the reference frame, represented by amplitude and phase, across frequency and time of the spectrogram; detecting regions of the spectrogram that have energy levels greater than a threshold level to produce detected regions; copying energy content from the detected regions into an energy vector; and performing an Inverse Fourier transform (IFT) based on the energy vector to transform the energy vector into in-phase (I) and quadrature (Q) (IQ) samples in the time-domain.

Some embodiments include a method performed by a network node for indicating a modulation and coding scheme for a wireless device operating in a coverage enhancement mode, wherein the wireless device operates with a first modulation and coding scheme using physical downlink shared channel repetitions and with a second modulation and coding scheme without using physical downlink shared channel repetitions, and wherein the second modulation and coding scheme is a higher order of modulation and coding than the first modulation and coding scheme, the method comprising configuring, when physical downlink shared channel repetitions are not used, the downlink control information to indicate one or more parameters related to the second modulation and coding scheme, the indication comprising at least the modulation and coding scheme field of the first modulation and coding scheme and one or more downlink control information field bits which are used in relation to repetitions when repetitions of a physical downlink shared channel are used.

A method and system for cross-technology communication from a WiFi device to a ZigBee device includes: generating, by a WiFi transmitter, to-be-transmitted symbol-level energy modulation bits information simultaneously carrying WiFi data bits and cross-technology data bits transmitted to the ZigBee device, wherein the cross-technology data bits are obtained based on symbol-level energy modulation; and a ZigBee receiver processing received signal strength indication sample information and initiating a cross-technology communication receiving process to obtain the cross-technology data bits needing to be received, and meanwhile a WiFi receiver obtaining the to-be-transmitted symbol-level energy modulation bits information through a standard WiFi receiving process, and then initiating a WiFi data recovery process to obtain original WiFi data bits.

Provided is a transmission method that improves data reception quality in radio transmission using a single-carrier scheme and/or a multi-carrier scheme. The transmission method includes: generating a plurality of first modulated signals s1(i) and second modulated signals s2(i) from transmission data, the plurality of first modulated signals s1(i) being signals generated using a QPSK modulation scheme, and the plurality of second modulated signals s2(i) being signals generated using 16QAM modulation; generating, from the plurality of first modulated signals s1(i) and the plurality of second modulated signals s2(i), a plurality of first signal-processed signals z1(i) and a plurality of second signal-processed signals z2(i) which satisfy a predetermined equation; and transmitting the plurality of first signal-processed signals z1(i) and the plurality of second signal-processed signals z2(i) using a plurality of antennas. A first signal-processed signal and a second signal-processed signal having identical symbol numbers are simultaneously transmitted at the same frequency.

A system and method of estimating metric values from digital samples of received communications signal carrying symbols modulated in a selected first modulation format and symbols modulated in a second modulation format. The selected first modulation format can be selected from among multiple supported first modulation formats. The system can receive the digital samples in sample blocks a plurality of which constitute a data frame. Each sample block can comprise a first region that contains first samples corresponding to the selected first modulation format or overhead samples regardless of the selected first modulator format or an index of the sample block in the frame; a second region that contains second samples corresponding to a second modulation format regardless of the selected first modulator format or an index of the sample block in the frame; and a third region in which whether the samples are first samples or second samples depends on the selected first modulation format or the index of the sample block in the frame. The system estimates first metrics according to the selected first modulation format for each of the first samples and second metrics according to the second modulation format for each of the second samples. The system also estimates both first metrics and second metrics for each of the third samples and then selects valid ones of the first metrics and second metrics for the third samples in accordance with the selected first modulation format or the index of the sample block in the frame.

A periodic phase modulation, having a period shorter than a symbol period, is applied as a source modulation, in addition to a symbol modulation, to signals transmitted between a transmitter and a receiver in a communication network. Symbol value elements can be sent from multiple transmitters (203, 303, 603, 703) to a receiver (607, 207) in the same symbol period can be processed on the basis of the source modulation without destructive interference. In some embodiments, the symbol value elements sent by different transmitters can be combined in the receiver. In some embodiments, symbol value elements sent by different transmitters can be distinguished in the receiver.