12 results about "Constant envelope" patented technology

The acoustic signal detection method comprises the following steps: generating a transmitting signal of a constant envelope system according to a signal modulation and time-frequency analysis principle; processing the received underwater acoustic signal data on the basis of beam forming and matched filtering theories to generate a matched related azimuth history graph; executing open peak retrieval in the matched related azimuth history graph, and extracting a peak point set corresponding to a suspected target; according to the azimuth and the time position of the peak point, extracting a time-frequency characteristic pattern of each peak point from the original data; and processing the time-frequency feature map by using a pre-trained dual-channel neural network model to determine a final detection result. The method can improve the accuracy of echo signal detection.

The application discloses a CE-OFDM communication and sensing integrated anti-nonlinear DOA estimation method, belongs to the field of communication sensing, and comprises the following steps: generating a 0dB peak-to-average power ratio CE-OFDM signal at a transmitting end, so that the CE-OFDM signal can drive a power amplifier to work in a saturation region, thereby avoiding nonlinear distortion while ensuring high power amplifier efficiency. A uniform linear array is used to receive signals at a receiving end, the signals are decomposed into a frequency domain through discrete Fourier transform, narrowband MVDR spatial spectra are independently calculated for each subcarrier frequency point, wideband spatial spectra are obtained through non-coherent fusion, and finally high-precision DOA estimation is realized through peak value searching. The application fundamentally suppresses power amplifier nonlinear distortion by using the constant envelope characteristic of CE-OFDM, avoids eigenvalue decomposition and source number estimation by combining the IMVDR algorithm, supports frequency point level parallel calculation, and realizes high-precision and low-complexity DOA estimation while ensuring communication reliability.

A method and apparatus for wireless communication are provided. The method comprises the following steps: a first device sends a first signal to a second device; wherein the first signal is transmitted by using a first waveform, and the first waveform is at least one of the following: a constant envelope OFDM waveform based on a DFT-s-OFDM waveform; carrying out enhanced DFT-s-OFDM (Discrete Fourier Transform- A waveform is generated based on a first waveform framework that supports the generation of a plurality of waveforms.

A transmitter having a transmitter signal processor (TSP) is provided for processing a plurality of signals for transmission to produce an output signal of constant envelope. The TSP has a sum input c

Systems, methods, and computer-readable storage media for generating and utilizing radar signals with embedded data are disclosed. Data is encoded onto a CPM waveform, which is then combined with a base radar waveform to produce a radar-embedded communication (REC) waveform. Both the CPM waveform and the base radar waveform may have a continuous phase and constant envelope, resulting in the REC waveform having a continuous phase and constant envelope. The changing (e.g., on a pulse-to-pulse basis) nature of the REC waveform causes RSM of clutter which may result in residual clutter after clutter cancellation, decreasing target detection performance of the radar system. In an aspect, various parameters may be utilized to dynamically adjust the performance of the radar system for a particular operating scenario, such as to enhance radar signal processing or enhance data communication capabilities.

This application provides a data transmission method, apparatus, electronic device, computer-readable storage medium, and computer program product. The method includes: receiving downlink control information (DCI) transmitted by a network device and carried on a physical downlink control channel (PDCCH), wherein the DCI is used to indicate the transmission mode and the resource location of downlink data of the first terminal device; receiving the downlink data based on the DCI; wherein the transmission mode includes a constant envelope transmission mode, so that downlink data transmission can adopt a constant envelope transmission mode in this process, thereby improving downlink communication performance.

The invention discloses a non-orthogonal multiple access system communication method based on index modulation and constant envelope modulation. According to the method, the number of activated subcarriers is selected at a sending end according to the bit number of data needing to be transmitted by users, index modulation is carried out on the subcarriers of all the users, and OFDM signals are embedded into phases of constant envelope signals through phase modulation after signals of all the users are superposed; and at a receiving end, firstly eliminating the cyclic prefix of the received signal, then carrying out channel estimation and equalization processing through pilot frequency, then deducing channel frequency response corresponding to each symbol by adopting a cubic spline interpolation method, and finally demodulating the user signal. According to the method, the robustness of the non-orthogonal multiple access system can be enhanced, and the low bit error rate can still be kept when the power difference between the users is not significant. The peak-to-average power ratio of the non-orthogonal multiple access system is greatly reduced, and the power consumption cost is reduced. And the anti-interference capability of the communication system on the frequency selective fading under the Rayleigh channel is obviously enhanced.

A transmitter may obtain a plurality of symbols encoding data to transmit wirelessly. A transmitter may transform the plurality of symbols using a unitary braid division multiplexing transform to produce a plurality of transformed symbols. A transmitter may scale the plurality of transformed symbols produce a plurality of scaled symbols. A transmitter may modulate a carrier signal by the plurality of scaled symbols to produce a constant envelope signal. A transmitter may transmit the modulated signal.

Aspects of the present disclosure relate to a method for constant envelope modulation. The method includes processing a first time-domain in-phase and quadrature (I / Q) composite signal, processing a second time-domain I / Q composite signal, combining the first time-domain I / Q composite signal and the second time-domain I / Q composite signal into a doublet pair signal, and forming a sum of the first waveform and the second waveform to obtain a constant envelope. The first time-domain I / Q composite signal is described by a first waveform and contains an intended high order modulation with a high peak-to-average ratio (PAR) and an envelope modulation as a function of time, and the second time-domain I / Q composite signal is described by a second waveform with an envelope change over time and a phase change over time of the second waveform defined as a function of the first waveform.

The invention provides a signal-to-noise ratio estimation method and device for a high-order modulation signal in a severe environment, electronic equipment and a storage medium, and the method comprises the steps: obtaining a high-order modulation signal of a non-constant envelope, and carrying out the normalization processing of the high-order modulation signal; performing signal-to-noise ratio estimation on the normalized signal based on a preset signal-to-noise ratio estimation model to obtain a low-precision signal-to-noise ratio parameter; wherein the signal-to-noise ratio estimation model is obtained by improving a second-order and fourth-moment signal-to-noise ratio estimation mode; demodulating the normalized signal by using a low-precision signal-to-noise ratio parameter, and decoding a symbol sequence obtained by demodulation to obtain an original signal estimated value; and modulating an original signal estimation value, and performing likelihood estimation on the modulated original signal estimation value and the normalized signal to obtain a high-precision signal-to-noise ratio parameter. According to the invention, accurate signal-to-noise ratio estimation can be carried out on a high-order modulation signal of a non-constant envelope in a severe environment.

A HPLC double-mode wireless communication preamble generation method and a communication method, the preamble generation method comprising: S1. setting an integer sequence with a certain calculation rule, taking the power index product of the sequence as the index parameter; S2. taking the natural number as the base, taking the product of the index parameter multiplied by the integer multiple of the circumference as the exponent to obtain the base sequence; S3. different transformations are performed on the base sequence, and the new extended sequence is formed by expansion and splicing; S4. copy a certain number of preamble unit sequence to form a complete preamble, and increase the mirror copy processing; S5. using a binary pseudo-random sequence with autocorrelation characteristics as a symbol scrambling sequence, the length of which is the length of the preamble unit sequence, periodically scrambling the preamble to obtain a complete preamble. The generated preamble has constant envelope characteristics, low power peak-to-average ratio, low device requirements, and can effectively support the application of communication terminal cost-sensitive communication systems; has excellent autocorrelation characteristics and sliding measurement characteristics, and has better noise-resistant signal characteristics.

The invention discloses a unitary space-time modulation and demodulation method and device, electronic equipment and a storage medium, and the method comprises the steps: carrying out the unitary space-time modulation of target data based on a unitary space-time modulation signal constellation set, and obtaining a unitary space-time modulation signal; a first signal in the modulation signal constellation set is generated based on a Hadamard matrix; and converting the unitary space-time modulation signal into an offset quadrature phase shift keying signal, and converting the offset quadrature phase shift keying signal into a continuous phase modulation signal. According to the unitary space-time modulation and demodulation method and device, the electronic equipment and the storage medium, the USTM constellation set head signal is constructed based on the orthogonal characteristic of the Hadamard matrix, the complete constellation set is generated through diagonal matrix design, finally, signal phase continuity is achieved through constant envelope processing, and the peak-to-average ratio can be remarkably reduced.