39results about How to "Reduce demodulation complexity" patented technology

The invention provides a faster-than-Nyquist rate block transmission method, a transmitter, a receiver and a system. Code elements to be transmitted are subjected to shaping filtering operation at a faster-than-Nyquist rate, cyclic superposing operation is performed, block symbols capable of keeping the faster-than-Nyquist rate and keeping head-tail circulation, protection intervals are added to symbol blocks, and transmitting base-band symbols are formed. Via the protection intervals, a receiving end is enabled to eliminate ISI caused by a multipath information channel via simple equalization, head-tail circulation block symbols formed via cyclic superposition are used for eliminating self ISI caused by transmission at the faster-than-Nyquist rate via time domain or frequency domain equalization, and therefore demodulation complexity of the receiving end can be lowered.

The invention provides an ARTM CPM demodulation and synchronization method with low implementation complexity. The method comprises the following steps: firstly performing two-stage delay on a received signal to obtain three branch signals; then separately performing mixing, low-pass filtering, matching filtering and phase compensation processing on the three branch signals, performing viterbi demodulation processing on the I branch signal, then calculating a timing error and a carrier phase error by using a demodulation processing result, and finally adjusting code NCO and carrier NCO by using filtering results of the timing error and the carrier phase error to realize symbol timing synchronization and carrier phase synchronization. Compared with the existing optical demodulator, the method provided by the invention has the advantages that the error bit performance loss is smaller, the number of matching filters and the number of states necessary for demodulation are greatly reduced, the implementation complexity can be greatly reduced, and that the stability of the system can be effectively improved.

The invention discloses a space-time continuous phase modulation (CPM) signal modulation method and a space-time CPM signal demodulation method. By the space-time CPM signal modulation method for preprocessing a CPM signal before modulation, a receiver can demodulate the received CPM signal in a linear signal demodulation way to reduce the demodulation complexity. Before CPM modulation is performed on a transmission sequence, the preprocessing before the modulation is performed at first, and comprises a segmented mapping step, an intra-segment redundancy addition step, a primary precoding step, an intra-segment redundancy regulation step, a time reversal and negation step, a secondary precoding step, a cyclic prefix addition step, an intra-segment redundancy addition step and a space-time signal formation step. In the methods, a transmitter adds cyclic prefixes to the sequence, and a signal received by the receiver is the cyclic convolution of a transmitted signal and a channel; therefore, when receiving the modulated CPM signal, the receiver can demodulate the CPM signal in the linear signal demodulation way.

The invention provides a quaternary continuous phase modulation-demodulation method which can increase the effective utilization rate of a spectrum, reduce signal coherent demodulation calculation and decrease complexity of a receiver. The technical scheme includes that in signal modulation, at an input end of a multi-system continuous phase modulation signal transmission system, a signal selection logic module performs combined logic operation according to front and rear adjacent input bit messages every time, two bit messages are mapped into absolute phase values of a certain determined position for transmitting modulation signals by a baseband signal collection module, baseband signals are modulated on carrier waves by transmitting the absolute phase values to an I modulation module and a Q modulation module, radio-frequency signals wirelessly received by an antenna are converted into the baseband signals by the aid of a quadrature demodulation module, the baseband signals are inputted to a baseband signal synchronization module, a symbol demodulation module takes amplitude values of real portions and imaginary portions of baseband complex signals at the synchronization position as bipolar numerical values of the two bit messages carried by a symbol, and the signals are demodulated by an information conversion module according to bipolar information conversion rules.

The invention provides a low complexity demodulation method for a multiple-input multiple-output carrier sequence modulation system. Dimensionality reduction MMSE estimation is used for each activation mode of each subcarrier in a signal subframe, modulation symbol estimation under each activation mode is obtained, and a corresponding complete estimation vector is formed according to the activation mode; the activation mode and the modulation symbol of each subcarrier are obtained through using an MAP criterion, estimation results of subcarriers form a complete signal subframe according to a sequence, and after activation mode detection on the signal subframe and error activation mode correction, a signal subframe with a legal activation mode is demodulated to obtain an information bit. The MMSE criterion is firstly used to estimate the modulation symbol under each activation mode, the MAP criterion is then used to calculate the maximum posteriori probability of different transmissionvectors under each activation mode, and through considering the posteriori probabilities of different transmission vectors, the estimation accuracy of each subcarrier is enhanced, and the error bit performance of the system is improved.

The invention provides a target tracking method and device, electronic equipment and a storage medium, and relates to the technical field of target tracking, the method comprises the following steps: a plurality of OTFS integrated signals sent by a vRAN base station are received, the plurality of OTFS integrated signals are coded and modulated in a time delay-Doppler domain, and pilot frequencies are different; demodulating the plurality of OTFS integrated signals based on air calculation, and determining the relationship between the channel information of the plurality of OTFS integrated signals in the time delay-Doppler domain and the pilot frequency; and target movement information is determined based on the relationship between the channel information and the pilot frequency, and the target movement information is used for realizing target tracking based on general inductance calculation integration. According to the invention, low-error and high-precision target tracking can be realized, and the target tracking efficiency is improved through integration of communication, perception and calculation.

A method is described for generating a M-D CPM waveform as a constant envelope, continuous phase signal capable of conveying a plurality of information symbols per symbol interval. Additionally, it provides for reducing the phase state space of the M-D CPM waveform, for reducing a number of trellis states required for demodulation of the M-D CPM waveform, and for implementing generalized tilted phase decomposition to reduce the cardinality of the phase state space of the multi-dimensional CPM waveform by a factor of 2. A device, computer program product and apparatus are also described.

The invention discloses a low-complexity system structure design method based on a high-order optical DPSK system, and belongs to the technical field of free space optical communication. According to the design, on the basis of a high-order light DPSK demodulation principle, according to corresponding distribution of each bit sequence on a constellation diagram, the most complex bit in the demodulation process is selected for constellation reconstruction, 0 and 1 of the bit are dispersed as much as possible to simplify a demodulation structure, and meanwhile, auxiliary bits are introduced to mark constellation points for transformation, so that the constellation reconstruction efficiency is improved. And the optical signal is transmitted to a receiving end through amplitude modulation, so that the purpose of assisting in demodulating other bits is achieved, and the system structure is further simplified. According to the high-order light DPSK optimization system, the higher the modulation order is, the simplification degree of the optimization system after constellation mapping reconstruction is higher, and therefore the higher the light power of each demodulated branch is, and the high-order light DPSK optimization system can save the laser emission power and has higher energy efficiency.

The invention provides a demodulation method, device, terminal and system. The demodulation method includes acquiring communication information of a cell; performing blind resolution on synchronization signals in the communication information and acquiring a blind resolution result; according to the blind resolution result, determining time scope information carried by the communication information; and performing demodulation on the communication information according to the time scope information. According to the scheme provided by the invention, acquired prior information can be utilized in aid for determining specific conditions of the communication information of the cell, so that hypothesis during the demodulation process of the communication information is reduced, demodulation complexity is reduced and power consumption is reduced.

The invention discloses a demodulation method and device for a small modulation index continuous phase signal. According to the technical scheme, the demodulation method comprises steps that differential precoding is conducted on an original signal through a continuous phase modulator at a transmitting end; a receiving end sends the received signal to a continuous phase reconstructor, and the continuous phase reconstructor receives the processed signal and smoothes the signal into a continuous phase; the continuous phase signal generator is used for receiving the signals outputted by the continuous phase reconstructor and converting the signals outputted by the continuous phase reconstructor into continuous phase signals with a modulation index of 0.5; and the continuous phase signal withthe modulation index of 0.5 is demodulated by a serial demodulator. The demodulation method mainly aims to solve problems of difficult continuous phase signal synchronization and complex signal demodulation, and is mainly applied to the fields of mobile communication, satellite communication, deep space communication, remote measurement and the like.