A system for peak-to-average-power ratio (PAPR) reduction of a frequency shifted plurality of digital broadcast signals taking into account the combined signal peaks in order to transmit the signals more efficiently in a single broadcast transmission system. The PAPR algorithm takes into account a rotating constellation phase offset for the shifted signals corresponding to the amount of applied frequency shift. In the case of a dual sideband In-Band-On-Channel (IBOC) signal typically used in conjunction with an FM carrier in the center, the sidebands can be interleaved to create a new IBOC signal definition and take the place of the FM carrier for an all-digital transmission that is backward compatible with IBOC receivers allowing for a gradual migration to all digital broadcasting.

A distributed antenna system includes a plurality of head-end devices for each receiving mobile communication signals from at least one corresponding base station, a hub communicatively coupled to the plurality of head-end devices, and a plurality of remote devices communicatively coupled to the hub, wherein the hub configured to distribute the mobile communication signals received from each of the plurality of head-end devices to the plurality of remote devices, wherein each of the plurality of remote devices is remotely disposed to transmit the distributed mobile communication signals to a terminal in service coverage, and wherein the hub includes a mixing processing stage configured to perform digital mixing processing on the mobile communication signals respectively received from the plurality of head-end devices, and a crest factor reduction (CFR) module disposed posterior to the mixing processing stage, with respect to a signal transmission direction.

Aspects of the disclosure relate to methods and an apparatus for transmitting a signal in a multi-layer hybrid resource spread multiple access (RSMA) system. A non-orthogonal multiple access (NOMA) user equipment (UE) demultiplexes a stream of bits into a plurality of layers, encodes each layer with a different coding rate, modulates each layer of encoded bits with a different modulation scheme, and spreads and scrambles each layer of modulated symbols with a different spreading code and a corresponding different scrambling code. Thereafter, the NOMA UE permutes the plurality of layers having spread and scrambled symbols into a plurality of interleaved layers, scales and phase rotates each interleaved layer with a different scaling factor and a corresponding different phase rotating factor, sums the scaled and phase rotated symbols, maps the summed symbols onto a set of allocated resources, and transmits the mapped symbols via the set of resources.

A method and apparatus in a communication system. The method includes: detecting multiple signal peaks of a target exceeding a predetermined threshold magnitude set to constitute one or more peak clusters; generating one or more noise shaping pulse clusters; assigning one or more noise shaping pulse clusters to the detected signal peaks in one or more peak clusters to clip the detected signal peaks in frequency domain; calculating an output signal based on the clipped signal peaks; the noise shaping pulse cluster comprises multiple sub-noise shaping pulses, bandwidths of the multiple sub-noise-shaping pulses are overlapped and a bandwidth of the noise shaping pulse cluster is greater than the bandwidth of the target signal.

High peak-to-average ratio of OFDM signals requires large back-off from an RF power amplifier's saturation power. A spectral shaper device therefore increases the output power and efficiency of the power amplifier. The shaper device performs linearization through digital predistortion, based on an out-of-band regrowth limit, as well as the EVM requirement for a particular data rate. The shaper can distribute the error energy, precisely, over frequencies such that each of the inband and out-of-band requirements is independently and individually met. The shaper distributes error energy to frequency regions in the spectrum to the maximally allowed by the standards and regulations, while not increasing the total error. The error energy is kept to the minimum where it is crucial in meeting EVM requirements. In this way, the shaper maximizes the allowable output power of the nonlinear power amplifier.

A method for controlling a combined waveform, representing a combination of at least two signals having orthogonal frequency multiplexed signal components, comprising: receiving information defining the at least two signals; transforming the information defining each signal to a representation having orthogonal frequency multiplexed signal components, such that at least one signal has at least two alternate representations of the same information, and combining the transformed information using the at least two alternate representations, in at least two different ways, to define respectively different combinations; analyzing the respectively different combinations with respect to at least one criterion; and outputting a respective combined waveform or information defining the waveform, representing a selected combination of the transformed information from each of the at least two signals selected based on the analysis.

High peak-to-average ratio of OFDM signals requires large back-off from an RF power amplifier's saturation power. A spectral shaper device therefore increases the output power and efficiency of the power amplifier. The shaper device performs linearization through digital predistortion, based on an out-of-band regrowth limit, as well as the EVM requirement for a particular data rate. The shaper can distribute the error energy, precisely, over frequencies such that each of the inband and out-of-band requirements is independently and individually met. The shaper distributes error energy to frequency regions in the spectrum to the maximally allowed by the standards and regulations, while not increasing the total error. The error energy is kept to the minimum where it is crucial in meeting EVM requirements. In this way, the shaper maximizes the allowable output power of the nonlinear power amplifier.

A method comprises performing iterations of a peak-to-average ratio (PAR) reduction algorithm on a modulated OFDM symbol, each of the iterations including: clipping the modulated OFDM symbol to produce a clipped modulated OFDM symbol; subtracting the clipped modulated OFDM symbol from the modulated OFDM symbol to produce a difference signal; weighting the difference signal using a weight that varies across the iterations, to produce a weighted difference signal that varies across the iterations; subtracting the weighted difference signal from the modulated OFDM symbol to produce a modified modulated OFDM symbol; and performing further PAR reduction operations on the modified modulated OFDM symbol to produce a PAR-reduced OFDM symbol for use in a next iteration.

A method for reducing peak-to-average power ratio, PAPR, in a Multiple Input Multiple Output, MIMO, communication system is disclosed. The method is performed in a precoder unit and includes: confining, by a differentiable cost function, power of a MIMO signal to be between a lower threshold, P.sub.low, and an upper threshold, P.sub.up, and applying a gradient method on the differentiable cost function until reaching a set power target for the MIMO signal, while keeping an Error Vector Magnitude, EVM, below a set EVM level.

Disclosed are a detection method and device for a digital intermediate frequency processing system. The method comprises: forming and transmitting excitation data to a digital intermediate frequency processing system; collecting detection data formed by processing the excitation data by the digital intermediate frequency processing system; and performing a bit-by-bit comparison on the detection data and reference data to form a detection result. Further provided is a computer storage medium.