According to a signal transmitting method, a signal receiving method, and a related device and system, a generated single-wavelength optical carrier may be split into N subcarriers with a same wavelength by using a splitting device, corresponding data modulation and corresponding amplitude spread spectrum modulation are performed on the N subcarriers by using N spreading codes and N low-speed data signals obtained by deserializing a received high-speed data signal, to obtain N spread spectrum modulation signals, and the N spread spectrum modulation signals are combined and output. A multicarrier generation apparatus or the like having a relatively complex structure does not need to be used for optical carrier splitting, and spectrum spreading does not need to be performed in a phase modulation manner in which a plurality of delay units or controllable phase units are required.

Embodiments of this application provide a data transmission method and device, so as to increase an uplink/downlink data transmission throughput. The method includes: splitting a to-be-transmitted transport block into N code blocks with incompletely equal sizes, where N is an integer greater than or equal to 2; performing error correction coding on the N code blocks to obtain N encoded bit blocks; and non-orthogonally transmitting the N encoded bit blocks by using resources that are the same in at least one dimension of a time domain, a frequency domain, a space domain, and a code domain.

A radio communication device includes a device substrate. A transmitter circuit is coupled to the device substrate to transmit a radio frequency signal to an antenna. The radio communication device also includes a receiver circuit coupled to the device substrate, where the receiver circuit includes an oscillator circuit to generate a baseband signal from a received radio frequency signal. The radio communication device further includes a feedback circuit coupled to the antenna and to the receiver circuit, where the feedback circuit couples a portion of the transmitted radio frequency signal to the oscillator circuit using a transmission line.

A phase adjustment method, a related device, and a system, the method comprising obtaining phases and amplitudes of M symbols adjusting a phase of each of the M symbols to an adjusted phase, wherein the adjusting the phase of each of the M symbols to the adjusted phase includes performing at least one of setting the adjusted phase of the first symbol to the phase of the respective symbol, or setting the adjusted phase of a symbol greater than the first symbol according to the phase of the respective symbol and further according to a sum of phases of all symbols whose amplitudes are greater than an amplitude threshold in a group of one or more symbols from a first symbol to an (i1).sup.th symbol.

A method for Peak to Average Power Ratio (PAPR) reduction at an input of analog to digital converter (ADC) of the receiver, the method includes mapping, by a mapper, an input symbol to an output symbol that maintains a peak power constraint at the input of the ADC; wherein the mapping is responsive to previously transmitted symbols; transmitting the output symbol by the transmitter; receiving, by the receiver, a received symbol that represents the output symbol; and de-mapping the received symbol, by a de-mapper of the receiver, to a de-mapped symbol that represents the input symbol.

An electronic device discussed herein may include an imbalance compensation logic that determines an imbalance parameter based at least in part on received quadrature signals from quadrature generation circuitry. The imbalance parameter may be determined using noise received by a receiver as an input radio frequency signal. By using the systems and methods described herein, an accuracy of detecting the imbalance may improve. Furthermore, by including the imbalance compensation logic internal to the electronic device, the imbalance compensation logic may provide continued imbalance detection over a lifespan of the electronic device.

Disclosed is a device capable of compensating for amplitude-modulation to phase-modulation distortion. The device includes a transmitter and a controller. The transmitter includes an amplifier circuit, a phase-shift adjustment circuit, and an output circuit. The amplifier circuit is configured to output an amplified signal according to an input signal. The phase-shift adjustment circuit, set between the amplifier circuit and the output circuit, includes at least one of an adjustable capacitor and an adjustable inductor and is configured to adjust the phase shift of the amplified signal according to a control signal. The output circuit is configured to output an output signal according to the amplified signal. The controller is configured to generate the control signal according to the input signal, in which the control signal varies with the input signal.

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 f.sub.0 and a first frequency f.sub.base, wherein the first frequency f.sub.base is, among frequencies corresponding to integer multiples of 128f, closest to the carrier frequency f.sub.0, and wherein f 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 f.sub.base to generate an OFDM symbol signal at the carrier frequency f.sub.0; and transmitting the OFDM symbol signal at the carrier frequency f.sub.0.

An OAM multiplexing communication system uses one or more OAM modes and multiplexes signals of one or more sequences for each OAM mode. A transmitting station includes a transmitting antenna using an M-UCA, and an OAM mode generation unit that simultaneously generates one or more OAM modes from each UCA. A receiving station includes a receiving antenna equivalent to the M-UCA, an OAM mode separation unit that separates signals received by each UCA for each OAM mode, and a received signal processing unit that estimates channel information for each OAM mode and performs an equalization process for each OAM mode by using a receiving weight calculated from the channel information. The received signal processing unit is configured to estimate, for each OAM mode, channel information of another OAM mode causing interference and calculate the receiving weight of a subject OAM mode by using the channel information of the subject OAM mode and said another OAM mode.

A transmitter includes: a modulation circuit that modulates a data sequence using QAM by mapping the data sequence to only four symbols each of which differs in phase by 90 degrees from an adjacent one of the four symbols and at least two of which have different amplitudes; and a transmission circuit that wirelessly transmits the data sequence mapped to the four symbols through the modulation by the modulation circuit, by assigning the data sequence mapped to the four symbols through the modulation by the modulation circuit to different subcarriers for Orthogonal Frequency Division Multiplexing (OFDM).