34 results about "Qpsk modulation" patented technology

The invention provides a satellite internet rapid high-precision navigation positioning method, a transmitting end modulates a navigation message and broadcasts the navigation message through a satellite internet frequency band, the advantage of satellite internet multi-carrier modulation is utilized, an I branch of QPSK is adopted for rapid parallel broadcasting, and the satellite internet multi-carrier modulation speed is improved. Basic navigation positioning parameters obtained for the first time are improved from the second level to the millisecond level of single-wave-position residence; a receiving end demodulates a received signal to obtain a navigation message, QPSK modulation is adopted, phase division is carried out on a Q branch supporting high-precision measurement and an I branch of the modulated message, and the Q branch is used for high-precision frequency offset estimation and time delay estimation; and the branch I carries out rapid navigation message broadcasting, so that high-precision frequency and time delay measurement is realized, and rapid message broadcasting is also realized.

The invention provides a frequency offset estimation method and system for a QPSK modulation format signal. The method comprises the steps of 1, converting an input serial signal into a parallel signal; 2, coarse frequency offset estimation with the symbol delay length being 1 and the interval extraction length being n is carried out on the parallel signals; 3, converting a coarse frequency deviation phase component, and performing coarse compensation; 4, performing fine frequency offset estimation with the symbol delay length of L and the interval extraction length of n on the signal subjected to coarse compensation; and step 5, adding the fine frequency offset and the coarse frequency offset to obtain final frequency offset, and restoring the final frequency offset to the phase for final frequency offset compensation. According to the method, the design thought of interval extraction is applied to the two-stage frequency offset estimation method, so that the operation complexity is reduced, and the resource use of the field programmable gate array is reduced.

The invention relates to the field of error vector magnitude calculation, in particular to a novel low-complexity error vector magnitude calculation method, which is used for simplifying EVM calculation of QAM (Quadrature Amplitude Modulation) of different orders, so that a redundant process generated in a judgment process during conventional calculation can be reduced, the processing speed is increased, and the processing efficiency is improved. The technical scheme comprises: determining a modulation type of a signal; performing normalization processing according to the modulation type of the signal; folding and translating the normalized signal; and judging whether the constellation image is equal to QPSK modulation or not, if so, calculating a signal EVM after folding transformation by adopting a calculation mode of a QPSK unit circle, otherwise, continuing to repeat folding and translation operations. The method is suitable for error vector magnitude calculation.

The embodiment of the invention discloses a data transmission method, a data transmission device and a data transmission system, which can be compatible with the existing 400ZR +, 800ZR and 800ZR + DSP (Digital Signal Processor) framing scheme, are more beneficial to hardware implementation, and can also be suitable for scenes adopting multi-wave or multi-subcarrier transmission in the future, such as 800Gbps multi-subcarrier transmission adopting QPSK (Quadrature Phase Shift Keying) modulation, 1.2 Tbps multi-subcarrier transmission adopting 16QAM (Quadrature Amplitude Modulation) modulation and 1.6 Tbps multi-subcarrier transmission adopting 16QAM modulation. And even transmission scenes with higher speed such as 2.4 T / 3.2 T and the like can be realized. The method comprises the steps that W data frames are sent, in one polarization direction, the number of symbols included in any data frame is 87552, each data frame comprises 12 subframes, the number of symbols included in each subframe is 7296, and W is an even number.

The invention discloses a sampling frequency offset phase compensation method and device under QPSK modulation, and relates to the technical field of phase compensation methods, and the method comprises the steps: collecting each load frame, and carrying out the QPSK modulation of the load frames; configuring a corresponding phase twiddle factor for each OFDM symbol based on the QPSK modulation of each load frame; in the calculation process of the phase twiddle factor, determining a corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each load frame have corresponding phase compensation values; according to the method, corresponding diversity combining is triggered according to each OFDM symbol, at the moment, a sampling frequency offset estimation value does not need to be directly estimated, approximate sampling frequency offset phase deflection information is obtained after multiple pieces of subcarrier information are combined and noise is reduced, correction is carried out according to the approximate sampling frequency offset phase deflection information, and a good correction effect can also be obtained under the low signal-to-noise ratio. Phase compensation is carried out on corresponding data before demodulation and decoding, and the receiving performance is improved.

Methods, systems, and devices for wireless communications are described. The described techniques provide for a user equipment (UE) to communicate using π / 2 binary phase shift keying (BPSK) modulation according to extended coding rates. In some cases, the UE may receive configuration information that supports modulation orders for π / 2 BPSK modulation extended to include modulation orders otherwise only configured for quadrature phase shift keying (QPSK) modulation. Further, the UE may support dynamic switching between π / 2 BPSK and QPSK modulation. For example, the UE may transmit or receive control signaling indicating a modulation order for an uplink transmission, where the UE or a network entity may determine which modulation scheme and order to use according to communication parameters associated with the uplink transmission, the UE, or both.

The present invention relates to the field of communication technologies, and discloses a high-security joint modulation method for information transmission based on multi-constellation indexing, which includes the following steps. At the sending end, the 4D hyperchaotic model is used to perform bitwise XOR encryption on the original data of A randomly generated binary bit streams; perform serial-to-parallel conversion on the encrypted data; perform subcarrier and symbol scrambling on the converted data; then use the multi-constellation indexing joint modulation method to modulate the key that has been converted into binary, construct a key index matrix, and combine the index matrix with two QPSK modulation formats to obtain a transmitted signal; the transmitted signal is transmitted through an OFDM system; at the receiving end, the correct key is extracted through the constellation point position information of QPSK modulation, and the received signal is decrypted and demodulated using the extracted key to obtain the original data. The present invention can achieve synchronous high-security and high-performance transmission of the key accompanying signal.

Methods, systems, and devices for wireless communications are described. The described techniques provide for a user equipment (UE) to communicate usingπ2binary phase shift keying (BPSK) modulation according to extended coding rates. In some cases, the UE may receive configuration information that supports modulation orders forπ2 ⁢BPSKmodulation extended to include modulation orders otherwise only configured for quadrature phase shift keying (QPSK) modulation. Further, the UE may support dynamic switching betweenπ2 ⁢BPSKand QPSK modulation. For example, the UE may transmit or receive control signaling indicating a modulation order for an uplink transmission, where the UE or a network entity may determine which modulation scheme and order to use according to communication parameters associated with the uplink transmission, the UE, or both.

A hybrid electronic warfare and communications system (EW / COMM) eliminates the space, power, weight, and cost of a dedicated communication system by exchanging messages with other nodes in a network as phase modulations of radar jamming signals. Some embodiments impose message phase modulations onto CW jamming signals, while other embodiments interleave message phase modulations with pseudorandom phase modulations of the jamming signals. Message chip rates can be matched to pseudorandom phase modulation chip rates. Messages are thereby obfuscated as either phase noise or random phase modulation of the jamming signals. Messages can be encoded as BPSK or QPSK modulations. Messages can be preceded by pre-established headers known to other nodes, and distinguished thereby from random noise modulations. Some embodiments include a dedicated COMMS module and / or antenna, while other embodiments implement the communications function mostly or entirely in software. Messages can be encrypted before transmission and decrypted after reception.

The embodiments of the present application disclose a data transmission method, and an apparatus and a system thereof, which are compatible with the existing DSP framing schemes 400ZR+, 800ZR, and 800ZR+, are more conducive to hardware implementation, and can further be applied to future transmission scenarios using multi-wave or multi-subcarrier transmission, for example, 800 Gbps multi-subcarrier transmission using QPSK modulation, 1.2 Tbps multi-subcarrier transmission using 16-QAM modulation, 1.6 Tbps multi-subcarrier transmission using 16-QAM modulation, or even higher rate transmission scenarios such as 2.4 T / 3.2 T. The method comprises: sending W data frames, the number of symbols comprised in any one data frame in a polarization direction being 87552, each data frame comprising 12 subframes, and the number of symbols comprised in each subframe being 7296, where W is an even number.

The present invention proposes a method for rapid and high-precision navigation and positioning in satellite Internet. The transmitting end modulates the navigation message and broadcasts it through the satellite Internet frequency band. By utilizing the advantages of multi-carrier modulation in satellite Internet, the I branch of QPSK is used for rapid parallel broadcast, and the acquisition of basic navigation and positioning parameters for the first time is improved from the second level to the millisecond level of single-wave position residence. The receiving end demodulates the received signal to obtain the navigation message. QPSK modulation is adopted, and the Q branch supporting high-precision measurement is separated from the I branch modulating the message. The Q branch is used for high-precision frequency offset estimation and time delay estimation. The I branch is used for rapid broadcast of the navigation message, which realizes both high-precision frequency and time delay measurement and rapid message broadcast.

The invention discloses a data encryption method based on a multi-stage dynamic iteration mechanism, and solves the problem that hidden dangers are brought to system security due to the fact that secret key information is repeatedly transmitted in pseudo noise information in the existing chaotic encryption technology. According to the method, encryption information in a 16 QAM modulation format and a key sequence in a QPSK modulation format are superposed into 64QAM signals for transmission by adopting different powers, encryption dimensions and a chaos model are embedded into small-power QPSK signals at the same time, and a multi-stage dynamic iteration mechanism is combined, so that more dynamic and flexible key information updating is realized, the safety performance of a system is improved, and the method is suitable for large-scale popularization and application. And potential safety hazards caused by a fixed encryption mode and encrypted information are avoided.

Disclosed in the embodiments of the present application are a data transmission method, apparatus and system, which can be compatible with existing DSP framing schemes of 400ZR+, 800ZR and 800ZR+, are more conducive to hardware implementation, and can also be applied to scenarios in which multi-wave or multi-subcarrier transmission is used in the future, such as 800 Gbps multi-subcarrier transmission using QPSK modulation, 1.2 Tbps multi-subcarrier transmission using 16QAM modulation, 1.6 Tbps multi-subcarrier transmission using 16QAM modulation, and even scenarios of transmission at higher rates such as 2.4 T / 3.2 T. The method comprises: sending W data frames, wherein in one polarization direction, the number of symbols comprised in any data frame is 43776, each data frame comprises six subframes, the number of symbols comprised in each subframe is 7296, and W is an even number.

The invention discloses a multi-domain joint air interface hidden transmission method based on USRP N210. The method comprises the following steps: step (1), a transmitter, a receiver and an eavesdropper are respectively realized by adopting USRP N210, and communication is carried out through a wireless air interface; step (2), the transmitter carries out constellation disguise on the signals modulated by the QPSK through WFRFT, and dynamically adjusts WFRFT parameters; step (3), adopting a frequency hopping technology to enable a signal frequency band after constellation disguising to jump at different frequency points at different moments; (4) the transmitter generates a frequency domain blindage signal by using a transform domain communication technology, so that the frequency domain blindage signal is complementary with the frequency hopping signal in the frequency domain, and D / A conversion and up-conversion processing are performed to transmit the signal; (5) the receiver firstly carries out A / D conversion and down-conversion processing on the received signal, and the original signal is accurately recovered; and step (6), the eavesdropping machine eavesdrops the communication behavior between the transmitter and the receiver by estimating the signal spectrum intensity and modulating detection. The method has the characteristics of high concealment and high analysis resistance.

The present invention relates to the field of error vector magnitude calculation, and specifically to a novel low-complexity error vector magnitude calculation method, which simplifies the EVM calculation of QAM modulations of different orders, thereby reducing the redundant processes generated during the judgment process during conventional calculations, improving processing speed, and improving processing efficiency. The technical solution includes: determining the modulation type of the signal; performing normalization processing according to the modulation type of the signal; folding and translating the normalized signal; determining whether the constellation image is equivalent to QPSK modulation, and if so, calculating the EVM of the signal after folding and transformation using the QPSK unit circle calculation method, otherwise continuing to repeat the folding and translation operations. The present invention is suitable for error vector magnitude calculation.

The invention discloses a transmitter system based on a time domain coding transmission-type metasurface and an information modulation method, and belongs to the technical field of wireless communication. The system comprises a time domain coding metasurface and a control system of the time domain coding metasurface, and the amplitude and phase of electromagnetic waves can be accurately regulated and controlled through time domain coding. The method specifically comprises the following steps of: applying control signals with different time delays to each column of units of the metasurface, and realizing 2bit phase coding of first-order harmonics through Fourier transform; and in combination with QPSK modulation, mapping the information bit stream into a transmission coefficient time domain waveform, and generating a phase gradient by using time delay to complete baseband signal modulation. The method does not need to depend on a traditional radio frequency link and a frequency mixer, has the advantages of low power consumption and low cost, remarkably reduces hardware complexity, and is suitable for efficient wireless communication of the 5GHz frequency band.

The invention discloses a QPSK (Quadrature Phase Shift Keying) error vector magnitude calculation and measurement method, a storage medium and a device, and the method comprises the following steps: S1, converting a received time domain signal into frequency domain data at a signal receiver, and obtaining equalized complex type data after least square (LS) channel estimation and MMSE (Minimum Mean Square Error) equalization; s2, based on a standard constellation point, performing normalization processing on the equalized complex number type data to obtain normalized data; s3, coordinate mapping and de-symbol processing are carried out on the normalized data, so that constellation points are all arranged in a first quadrant; s4, calculating an error vector set from the constellation point set after symbol removal processing to the standard constellation points; and S5, calculating an error vector magnitude (EVM) of the QPSK signal. According to the new scheme of the QPSK modulation mode, the operand and redundant logic judgment can be effectively reduced, a CPU assembly line and a vector operation method can be used, the full load of the process can be guaranteed to the maximum extent, and therefore the processing speed is increased.

The application discloses an encryption communication method and system based on probability shaping and double single sideband modulation, and the method comprises the following steps: receiving an original bit stream and an initial key, generating a chaotic sequence according to the initial key by using a hyperchaotic model; calculating a mask factor according to the chaotic sequence; performing constellation mapping processing on the original bit stream to obtain a constellation diagram; performing rotation encryption on the constellation diagram according to the mask factor to obtain an encrypted signal; performing QPSK modulation on the encrypted signal to obtain a left sideband carrier signal; performing constellation mapping on the initial key after repeating and superimposing to obtain a key signal; performing probability shaping and QPSK modulation on the key signal to obtain a right sideband carrier signal; superimposing the left sideband carrier signal and the right sideband carrier signal to obtain a mixed signal, and transmitting the mixed signal to a receiver through a transmitter; and the safety and reliability of key transmission are improved while the signal transmission efficiency is ensured.

This invention discloses a method for estimating the physical layer four-phase complex scrambling code sequence for low-Earth orbit satellite communication systems, belonging to the field of satellite communication technology. The method includes: selecting a target signal subjected to four-phase physical layer complex scrambling based on inter-frame BPSK modulation and intra-frame QPSK modulation criteria to obtain an equivalent sequence; analyzing the periodicity of the equivalent sequence to obtain an estimated equivalent sequence, then performing polynomial matching to obtain the generator polynomial of the estimated equivalent sequence, further analyzing to obtain the equivalent sequence generation rule and generating a local equivalent sequence; traversing according to the equivalent sequence generation rule to generate candidate adjoint sequences, combining them with the estimated equivalent sequence to obtain a candidate scrambling code sequence; descrambling the target signal according to the candidate scrambling code sequence, and if the descrambled target signal meets the decision condition, outputting the candidate scrambling code sequence as the scrambling code sequence. This invention solves the problem in blind signal demodulation where the sample phase transformation caused by the four-phase physical layer complex scrambling of the original signal prevents effective demodulation of the target signal.

The invention discloses a quantum enhancement detection method and device based on dual-class heterodyne partition displacement, and the method comprises the steps: designing a hybrid quantum receiver based on a binary phase shift keying signal under the condition that a transmitting end uses a QPSK modulation signal, and deducing the error probability of the hybrid quantum receiver. The method has good detection performance, and can be practically used in a quantum detection system under the condition of considering the influence of the detection efficiency and quantum efficiency of the photon number detector.

The invention discloses a power line communication anti-noise method and device based on MMSE equalization and adaptive notch, and belongs to the technical field of power line communication, the method comprises the following steps: dynamically selecting a polar code rate at a sending end according to the SNR of a current channel, and carrying out polar code coding on information bits; qPSK / OFDM modulation is carried out on code words after polar code coding to form sending signals, dense pilots are inserted during QPSK modulation, and a cyclic prefix CP is added during OFDM modulation; carrying out time domain processing on the sending signal to suppress impulse noise, and carrying out frequency domain processing to suppress periodic noise; and introducing a noise sensing MMSE iterative equalizer at a receiving end, and carrying out iterative equalization decoding by using the soft information decoded by the polarization code to obtain an output signal. The interference influence of communication noise can be reduced, and the power line communication performance is improved.

The invention provides a transmitting circuit and a transmitter, and relates to the technical field of communication, and the transmitting circuit comprises N first switches, N QPSK modulation branches and a first synthesizer. The QPSK modulation branches are in one-to-one correspondence with the first switches, and the input ends of the QPSK modulation branches are connected with the corresponding first switches; the QPSK modulation branch is used for generating a QPSK signal; the amplitudes of the QPSK signals correspondingly generated by the QPSK modulation branches are different from one another; the first synthesizer is connected with the output ends of the QPSK modulation branches and used for combining the QPSK signals output by the QPSK modulation branches into first radio frequency (RF) signals. According to the technical scheme, the system power consumption can be reduced.

The application discloses a power distribution method and device and a computer readable storage medium. The power distribution method comprises the following steps: acquiring downlink instantaneous PRB utilization ratio of a target cell corresponding to a base station and a proportion of users using QPSK modulation in the downlink, wherein the target cell is an NR-FDD cell and / or an LTE-FDD cell; and adjusting available power of the target cell according to the downlink instantaneous PRB utilization ratio of the target cell and the proportion of users using QPSK modulation in the downlink. The application can improve the wireless throughput rate of users in a cell.

The invention discloses a data transmission performance optimization method based on reverse Cantor fractal coding, and solves the problem that key information is easy to expose after relatively high repetition due to a simple configuration structure in a traditional chaotic disturbance scheme based on key follow-up transmission. According to the invention, reverse Cantor fractal coding is carried out on initial key information to obtain a fractal structure key, on one hand, the fractal structure key is adopted to carry out bit encryption, subcarrier encryption and symbol encryption on service data, and on the other hand, small sending power is distributed to the fractal structure key and QPSK modulation is carried out. According to the method, a fractal structure secret key signal with small sending power is obtained, then superposition and probability shaping are carried out on the fractal structure secret key signal with small sending power and an encrypted QPSK signal with large sending power, a large amount of information redundancy is avoided, 0.7 dB to 0.9 dB of receiving sensitivity is improved, and the transmission performance of an optical communication system is improved.

Methods, systems, and devices for wireless communications are described. The described techniques provide for a user equipment (UE) to communicate using binary phase shift keying (BPSK) modulation according to extended coding rates. In some cases, the UE may receive configuration information that supports modulation orders for BPSK modulation extended to include modulation orders otherwise only configured for quadrature phase shift keying (QPSK) modulation. Further, the UE may support dynamic switching between BPSK and QPSK modulation. For example, the UE may transmit or receive control signaling indicating a modulation order for an uplink transmission, where the UE or a network entity may determine which modulation scheme and order to use according to communication parameters associated with the uplink transmission, the UE, or both.

The invention discloses a 5G base station OFDM (Orthogonal Frequency Division Multiplexing) sensing integration waveform design and dynamic resource allocation strategy method, and relates to the field of 5G communication sensing integration. The problems that communication performance and sensing performance are mutually limited and resources need to be efficiently allocated under a limited frequency spectrum due to competition existing in existing frequency spectrum and time slot resource occupation are solved. The method comprises the following steps: determining a subcarrier index set of a DMRS in an OFDM signal according to a 3GPP protocol, setting that one OFDM signal contains N subcarriers, and setting the DMRS subcarrier set as a specific set; selecting an optimal subset from the DMRS subcarrier set as a sensing pilot frequency, and reserving unselected DMRS subcarriers for communication channel estimation; adopting a BPSK (Binary Phase Shift Keying) or QPSK (Quadrature Phase Shift Keying) modulation mode to optimize a sensing pilot signal And a receiving end detects and senses the peak position of the pilot signal through discrete operation, calculates time delay, calculates a target distance and completes target parameter estimation.

This invention discloses a multi-level biorthogonal keying signal demodulation method based on STFT-CNN, comprising: converting the source into I-channel information bits and Q-channel information bits; mapping the information bits in the I-channel and Q-channel information bits to I-channel and Q-channel spreading code sets respectively; adding repetition coding after each spreading code in the I-channel and Q-channel spreading code sets respectively, i.e., repeating each spreading code several times; and then performing QPSK modulation to generate an MBOK modulated signal; extracting time-frequency features from the MBOK modulated signal and inputting them into a machine learning model, outputting the corresponding likelihood probability, which indicates the category or spreading code state of the current time-frequency feature sample; and recovering the source information based on the one-to-one mapping relationship between the category or spreading code state and the information bits of the source. This invention improves demodulation performance.

The present invention discloses a method for calculating the bit error rate of an artificial noise-assisted MIMO system under a non-perfect channel. Through the method in which the communicating parties mutually send channel pilot sequences, both the transmitting and receiving ends obtain the main channel estimation information. The transmitting end performs QPSK modulation on the confidential binary information data, and then generates zero-space artificial noise and a precoding matrix according to the main channel state information estimated by the transmitting end, and transmits the artificial noise together with the confidential signal after the precoding processing. The receiving end obtains the main channel state information according to the pilot signal of the transmitting end and generates a deprecoding matrix, decodes the confidential signal, and finally decodes the confidential signal using the maximum likelihood detection method. The artificial noise technology of the present invention increases the difference in noise levels between the receiving end and the illegal eavesdropping end, and improves the confidentiality of communication under a non-perfect channel.

The present invention discloses a cell data processing method, apparatus, computing device and computer storage medium. The method includes: calculating the first critical path loss and the second critical path loss of the QPSK modulation mode in the target cell; calculating the first coverage distance corresponding to the first critical path loss, and calculating the second coverage distance corresponding to the second critical path loss; calculating the ideal proportion of the QPSK modulation mode in the target cell according to the first coverage distance and the second coverage distance; obtaining the actual proportion of the QPSK modulation mode in the target cell; judging whether the actual proportion of the QPSK modulation mode is greater than the ideal proportion of the QPSK modulation mode; if so, determining that the target cell is a cell whose modulation mode is to be optimized. This solution can achieve cell load reduction without increasing bandwidth resources and changing the cell coverage range, thereby having the characteristics of high efficiency, low cost and no impact on the service performance of adjacent cells, and is suitable for large-scale application and implementation.

The invention discloses a chaos polarization code sending method, a chaos polarization code receiving method, a chaos polarization code sending end, a chaos polarization code receiving end and a chaos polarization code sending method based on grouped multicarrier modulation. The method comprises the following steps: dividing original data into blocks, coding the original data blocks to obtain coded data, determining the reliability of each bit position according to channel characteristics in the coding process, selecting the most reliable part of bits to place information bits, and setting other positions as frozen bits; performing QPSK modulation on the coded data to obtain a modulation signal, generating a disturbance factor through a four-dimensional chaotic system, and encrypting the frozen matrix and the modulation signal to obtain an encrypted signal; and mixing the obtained initial value of the four-dimensional chaotic system with the encrypted signal to obtain transmission information, and transmitting the transmission information through an orthogonal frequency division multiplexing technology. According to the invention, the optimal transmission rate is realized through polarization coding; and through the chaotic encryption technology, the secure transmission of the dynamic key is realized, and the security of signal transmission is ensured.