Abstract: The present invention discloses a modulation method and a modulation apparatus applicable to an OvXDM system, and an OvXDM system. On the one hand, an initial envelope waveform is virtually cut off, and a modulation-domain shift interval is calculated by using a virtual cutoff width of the initial envelope waveform, such that a symbol width obtained after modulation becomes smaller, and a transmission rate is improved; on the other hand, because the initial envelope waveform is virtually cut off but not really cut off, shifting and superimposition are still performed on an initial envelope waveform with tailing, such that the waveform still retains a good performance, such as a relatively narrow width and relatively fast side lobe attenuation, in a corresponding domain. Therefore, in the present invention, the good performance of the waveform is retained in the corresponding domain while the transmission rate is increased.

Abstract: The present application discloses a forward and backward smooth decoding method and device suitable for an OvXDM system, and a system. Importance weights of particles in a particle set corresponding to a symbol are calculated by using a forward process and a backward process, and screening is performed with reference to forward importance weights of particles and backward importance weights of particles, to output a final decoding sequence.

Abstract: An overlapped multiplexing-based modulation and demodulation method and device are disclosed. In the modulation method, a precoding structure is used, and a transmit end first performs parity check product code-based coding on an input information sequence, generates a factor graph for a coding result and according to a coding rule, then performs overlapped multiplexing-based modulation and coding, and transmits a coded signal by using an antenna. In the demodulation method, a signal is transmitted by using a channel, and after receiving the signal by using an antenna, a receive end first performs digital signal processing, including processes such as synchronization and equalization, then performs overlapped multiplexing-based demodulation and decoding, and finally performs factor graph-based belief propagation decoding on a decoding result, to finally obtain a decoded sequence.

Abstract: In an overlapped multiplexing-based decoding method and device, and modulation and demodulation method and system provided in this application, a convolution operation with a header and without a tail is split into group operations with both a header and a tail by using a slide group decoding scheme and based on association between adjacent symbols in an OvXDM system, and then each group of sequences is decoded by using a corresponding decoding algorithm.

Abstract: The present invention discloses a decoding method and a device applied to an OvXDM system, and an OvXDM system. An access node in a Trellis diagram corresponding to the OvXDM system is selected in a decoding process. A superior path is selected by improving a method for calculating an accumulated branch measurement and with reference to a weighting factor. In addition, a node with a smallest accumulated branch measurement is extended, and a best decoding path is selected. When the present invention is applied to a decoding process of an OvXDM system in which a quantity of times of overlapped multiplexing or a quantity of coding branches is relatively large, design complexity and a calculation amount of the OvXDM system are reduced, so that the OvXDM system has a relatively low bit error rate, and performance is improved.

Abstract: This application discloses a fast decoding method and device suitable for an OvXDM system, and an OvXDM system. According to this method, there is no need to traverse all state nodes and expanded paths of the state nodes in a decoding process, and only some state nodes and paths are selected through measure sorting for expansion. Therefore, the decoding complexity can be greatly reduced and decoding efficiency is improved. The decoding complexity does not increase drastically as a number K of times of overlapped multiplexing increases, as in a conventional decoding solution. This resolves the problem that the spectral efficiency conflicts with the decoding complexity and the decoding efficiency.

Abstract: The present application discloses a signal sampling and recovery method and apparatus applicable to an OvXDM system, and the OvXDM system. The method includes: constructing, based on design parameters, an observation matrix ? that is irrelevant to an original signal y, wherein the observation matrix ? is a two-dimensional M*S matrix, S is a length of the original signal y, and M is smaller than S; compressing the original signal y based on a formula Ycs=?Y, to obtain a M*1 compressed signal Ycs, wherein Y is a S*1 column vector that is obtained according to the original signal y; and reconstructing the compressed signal Ycs based on a predetermined algorithm, so as to recover the original signal y. The present application implements accurate recovery of the original signal at a reduced sampling rate, thereby reducing hardware requirements of the system and improving feasibility of the technical solution.

Abstract: This application discloses a soft value extraction method and device applicable to an OvXDM system, and the OvXDM system. In the method, waveform coding is performed on all symbols in a hard value sequence, to generate a predictive value after overlapped coding; the symbols in the hard value sequence are reversed one by one, and overlapped coding is performed on each reversed symbol and associated symbols before and after the reversed symbol, to generate a predictive value of the reversed symbol; and for each symbol in the hard value sequence, a soft value of the current symbol is calculated based on A×(+1??1), where A is a coefficient related to a channel type, +1=?yrx?y+1?, and ?1=?yrx?y?1?2; if y+1 is a predictive value of the symbol obtained after overlapped coding and before reversing, y?1 is a predictive value of the symbol obtained after overlapped coding and reversing; and yrx is a received signal sequence.

Abstract: This application discloses a decoding method for an OvXDM system, including: generating an augmented matrix B related to a received symbol information sequence; performing singular decomposition on the augmented matrix B; and performing decoding by using a total least square method, to obtain a decoded output information sequence. This application further discloses an OvXDM system. In a specific implementation of this application, decoding is performed by using the total least square method.

Abstract: The present invention provides a signal modulation method. The method includes: generating a transmit signal pulse waveform, where a width of the pulse waveform is ?, each pulse waveform is associated with n symbols (n>1), a width of each symbol is ??, and ?? = ? n ; performing an operation on every n consecutive symbols in a to-be-sent symbol flow and the pulse waveform according to a preset operation manner, to generate an associated signal of the symbols and the pulse waveform; and sending the associated signal by using a transmission channel. The present invention helps improve spectral efficiency of a system. In addition, symbols are mutually constrained based on a correlation between the symbols, and information symbols are scattered to a plurality of symbols, thereby helping improve a capability of resisting noise and attenuation by a signal.

Abstract: A metamaterial comprises a plurality of electrically controllable metamaterial units each comprising a varactor diode; the predetermined angle is an angle at which an electromagnetic wave is reflected from a surface of the metamaterial; there is an association relationship between the predetermined angle and the first phase difference; the method comprises: determining a first phase difference between electromagnetic waves reflected by two adjacent electrically controllable metamaterial units in a metamaterial based on a predetermined angle; determining a target capacitance of the varactor diode in each electrically controllable metamaterial unit based on the first phase difference; and adjusting a capacitance of the varactor diode in each electrically controllable metamaterial unit to the target capacitance.

Abstract: The present invention discloses a metamaterial, and a method and an apparatus for adjusting a frequency of the metamaterial. The metamaterial includes a substrate material, and an electrically controllable microstructure unit array disposed on the substrate material and including a plurality of electrically controllable microstructure units. Each electrically controllable microstructure unit includes an external metal structure, an internal metal structure, and a varactor diode. The internal metal structure and the external metal structure define a ring-shaped channel. The varactor diode is disposed in the ring-shaped channel of each electrically controllable microstructure unit, and is configured for adjusting an operating frequency of each electrically controllable microstructure unit according to a voltage applied across the varactor diode.

Abstract: The disclosure relates to an overlapped multiplexing modulation method, apparatus, and system.

Abstract: A method includes: receiving a to-be-decoded symbol sequence, where the to-be-decoded symbol sequence includes N symbols; dividing the received to-be-decoded symbol sequence into a first symbol sequence and a second symbol sequence; calculating first distances between the first symbol sequence and each of corresponding 2K ideal superimposed symbol sequences, and obtaining paths corresponding to relatively small distances based on the first distances; sequentially performing sequence detection on each symbol in the second symbol sequence based on the paths corresponding to the 2k-1 relatively small distances, calculating second distances between each symbol in the second symbol sequence and each ideal symbol sequence, and after the sequence detection is performed on a last symbol, obtaining an ideal symbol sequence corresponding to a minimum distance based on the second distances; and using the ideal symbol sequence corresponding to the minimum distance as an output symbol sequence.

Abstract: The disclosure relates to an antenna reflector phase correction film and a reflector antenna. The antenna reflector phase correction film includes a first substrate, a second substrate, and multiple artificial microstructures disposed between the first substrate and the second substrate, the artificial microstructures are wires made of electrically conductive materials, and an electromagnetic wave, emergent after being reflected by an antenna reflector attached with the antenna reflector phase correction film, has an equiphase surface. According to the disclosure, the antenna reflector phase correction film has specific refractive index distribution internally, so that a surface emergent phase of a reflector can be corrected after attaching onto a surface of a conventional reflector, a phase error caused due to installation or processing is improved, a complete flat emergent equiphase is obtained, and then a far-field performance (such as a higher gain) is improved.

Abstract: A Cassegrain-type metamaterial antenna, includes: a metamaterial main reflector having a central through-hole, a feed source disposed in the central through-hole, and a sub-reflector disposed in front of the feed source, where an electromagnetic wave radiated by the feed source is emerged in a form of a plane wave after being reflected by the sub-reflector and the metamaterial main reflector in sequence; the metamaterial main reflector includes: a first core layer and a first reflection layer disposed on a rear surface of the first core layer, where the first core layer includes at least one first core layer lamella, and the first core layer lamella includes: a first base material and multiple first conductive geometric structures disposed on the first base material; and a far focus of the sub-reflector coincides with a phase center of the feed source. A paraboloid is replaced with a lamellar metamaterial main reflector.

Abstract: The disclosure relates to a metamaterial antenna, where the metamaterial antenna includes an enclosure, a feed, a first metamaterial that clings to an aperture edge of the feed, a second metamaterial that is separated by a preset distance from the first metamaterial and is set oppositely, and a third metamaterial that clings to an edge of the second metamaterial, where the enclosure, the feed, the first metamaterial, the second metamaterial, and the third metamaterial make up a closed cavity; and a central axis of the feed penetrates center points of the first metamaterial and the second metamaterial; and a reflection layer for reflecting an electromagnetic wave is set on surfaces of the first metamaterial and the second metamaterial, where the surfaces are located outside the cavity.

Abstract: Disclosed is a Cassegrain microwave antenna, which comprises a radiation source, a first metamaterial panel used for radiating an electromagnetic wave emitted by the radiation source, and a second metamaterial panel having an electromagnetic wave convergence feature and used for converting into plane wave the electromagnetic wave radiated by the first metamaterial panel. Employment of the principle of metamaterial for manufacturing the antenna allows the antenna to break away from restrictions of conventional concave lens shape, convex lens shape, and parabolic shape, thereby allowing the shape of the Cassegrain microwave antenna to be panel-shaped or any shape as desired, while allowing for reduced thickness, reduced size, and facilitated processing and manufacturing, thus providing beneficial effects of reduced costs and improved gain effect.

Abstract: The present invention discloses a Cassegrain satellite television antenna comprising a metamaterial plate. The metamaterial plate comprises a core layer. The core layer comprises core sublayers. Each core sublayer comprises a circular area and a plurality of annuli distributed around the circular area. According to the Cassegrain satellite television antenna of the present invention, the traditional parabolic antenna is replaced with a sheet-like metamaterial plate which is easier to process and has a lower cost. In addition, the present invention also provides a satellite television receiving system equipped with the above-mentioned Cassegrain satellite television antenna.

Abstract: A front feed microwave antenna, which comprises a radiation source, a first metamaterial panel used for radiating an electromagnetic wave emitted by the radiation source, a second metamaterial panel, and a reflective panel affixed to the back of the first metamaterial panel. The electromagnetic wave is emitted via the first metamaterial panel, refracted by entering the second metamaterial panel, reflected by the reflective panel, and finally re-refracted by reentering the second metamaterial panel, then finally parallel-emitted.