94results about How to "Improve frequency efficiency" patented technology

This invention is related to a cognitive Multi-Input Multi-Output (MIMO) radio frequency (or laser) radar with large-area synchronized multi-dimensional hopping spread spectrum and Interference-Free Windows (IFWs) for autonomous vehicles comprising of (1) analog component; (2) digital baseband component; (3) multi-dimensional hopping code generator; (4) large-area time synchronization; (5) cooperative IFW; and (6) cognitive engine. The new MIMO radar can provide interference-free environmental perception intelligently by the multi-dimensional IFWs formulated by beat-frequency hopping, beat-time hopping, discrete sequence (DS), cooperative IFW, array processing, and image denoising and fusion, etc. This invention increases the frequency efficiency greatly, and be applied to autonomous vehicles and robotics under sparse, dense, mixed autonomous and human driving, or completely autonomous driving environments.

A multicarrier communication method capable of improving the frequency utilization efficiency and the throughput of the communication system, while satisfying the QoS. A communication terminal reports the CQI about all of the subchannels included in the bandwidth of a communication channel during a first CQI report, as shown in the upper figure portion. Unlike the first report, during the second and following CQI reports, in which much time is left in terms of the permissible delay time, the communication terminal reports the CQI only about subchannels 1 and 2 assigned by the second and following frequency assignments, as shown in the lower figure portion.

The disclosure is related to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). The disclosure is related to a precoding/beamforming using a massive antenna. A method for operating a base station in a wireless communication system includes transmitting vertical reference signals and horizontal reference signals that are generated based on an interference relation between terminals, receiving long-term channel information determined by using the vertical reference signals and the horizontal reference signals, transmitting group-specific reference signals beamformed by a first beamformer generated based on the long-term channel information, receiving short-term channel information determined by using the group-specific reference signals, and transmitting a data signal beamformed by a second beamformer generated based on the short-term channel information.

A method of broadcasting frequency policy information in a cognitive radio based communication system, apparatus therefore and a communication method using the same are disclosed. In particular, a policy broadcaster is provided as a subject performing a broadcast of frequency policy information in cognitive radio communication. A method of broadcasting frequency policy information using the same and a method of performing cognitive radio communication by obtaining frequency policy information using the same are provided. Moreover, an enhanced superframe structure, which is capable of providing a seamless service in case that a narrowband terminal is introduced in the middle of a superframe, is provided.

By deciding positions of frequencies used via a relay station by a system in advance for assignment of boundary frequencies, frequencies of a central frequency more likely to be affected by the relay station are also mapped by avoiding a signal thereof. Alternatively, an adjacent cell whose central frequency is affected changes depending on a position of the relay station and thus, locations set to be highly likely to interfere with the central frequency of the adjacent cell is reduced by setting a region of the boundary frequencies permitted to the relay station in accordance with the position of the relay station.

The invention discloses a data transmission method, a base station, a terminal and a mobile communication system. The data transmission method comprises the following steps: configuring an uplink spectrum in a paired spectrum to a full duplex spectrum by the base station; and configuring corresponding resources of the terminal in a sub-frame to implement downlink transmission in the full duplex spectrum when the base station determines that the terminal does not need to transmit data or feed back information in the sub-frame of an uplink radio frame according to a timing relationship of HARQ, and transmitting resource scheduling information of sub-frame uplink and downlink transmission on the full duplex spectrum or downlink spectrum. According to the data transmission method, the base station, the terminal and the mobile communication system disclosed by the invention, the downlink transmission can be distributed in the uplink spectrum, and thus frequency resources of the network can be used more flexibly, the efficiency of the frequency can be increased, the frequency resources of operators can be used more effectively, simplicity and small access delay can be achieved, good compatibility can be brought to different versions of the terminals, and the throughput of the whole system and terminal experiences can be improved.

The present invention relates to a transmission and reception method of a radio signal by a terminal in a wireless communication system. According to the present specification, disclosed is a method comprising the steps of: determining whether or not transmission of an uplink radio signal or reception of a downlink radio signal allocated to a terminal is possible on a slot configured to comprise at least one of one or more downlink symbols for downlink transmission, one or more flexible symbols and one or more uplink symbols for uplink transmission; and controlling the transmission of the uplink radio signal or the reception of the downlink radio signal on the basis of the determination. According to the present invention, the terminal can transmit the uplink radio signal even if the configuration of the slot is changed, and thus uplink radio signal transmission omission or unnecessary retransmission of the uplink radio signal can be prevented. And by means of defining valid timing of the uplink signal such as a physical random access channel, the frequency efficiency of the network can be increased and the energy consumption of the terminal can be reduced.

Provided is a communication control apparatus including a communication unit configured to receive, from a base station of a first radio communication system, grant information that specifies a resource for secondary use within a frequency resource assigned to the first radio communication system operated with a frequency division duplex scheme, and a communication control unit configured to operate a second radio communication system with a time division duplex scheme on the resource for secondary use during a period that is associated with the grant information.

To provide a communication apparatus and a communication method capable of simultaneously directing main beams to reception stations and transmission stations the numbers of which exceed the number N of RF systems provided to the communication apparatus itself. The communication apparatus according to the present invention includes a transmission unit configured to generate non-orthogonal multiplexed signals including downlink signals addressed to multiple terminal apparatuses, an antenna capable of forming an antenna directivity pattern including multiple main beams, and a transmission beam control unit configured to generate a signal controlling the antenna directivity pattern, wherein the non-orthogonal multiplexed signals are simultaneously transmitted by use of the multiple main beams, and the number of main beams included in the antenna directivity pattern is more than the number of RF systems of the antenna.

In a transmitter, at least one pilot carrier which is modulated with a signal sequence including a reference pilot signal sequence represented by any of amplitude modulation vectors {α, α, −α, −α}, {α, −α, −α, α}, {−α, α, α, −α}, and {−α, −α, α, α} where α represents a real number other than 0, is generated, and an OFDM/OQAM multicarrier modulation signal is transmitted. In a receiver, the OFDM/OQAM multicarrier modulation signal is demodulated, and transmission channel characteristics are estimated and corrected based on two successive demodulation vectors in a time direction which are obtained by demodulating the pilot carrier.

A terminal apparatus according to an aspect of the present embodiment acquires multiple pieces of sounding reference signal (SRS) resource set configuration information indicating a configuration of multiple SRS resources, transmits an SRS and an uplink shared channel (PUSCH) based on the multiple SRS resources, acquires information (SRI) indicating one of the multiple SRS resources included in a piece of SRS resource set configuration information of the multiple pieces of SRS resource set configuration information, from control information (DCI) transmitted via a downlink control information channel (PDCCH), and acquires, from the DCI, information indicating whether only one of the multiple pieces of SRS resource set configuration information is associated with the PUSCH.

Disclosed is a method for applying non-orthogonal multiple access in a multi-hop relay system constituted by a base station, a relay, a first user terminal, and a second user terminal, including: receiving, by the first user terminal, a first data signal which the first user terminal needs to receive and a second data signal which the second user terminal needs to receive from the base station through a first phase; receiving, by the first user terminal, a third data signal from the base station through a second phase when the second data signal is relayed through the second phase by the relay; and removing an interference signal included in the third data signal received through the second phase by using the second data signal which the first user terminal receives through the first phase.

To provide a system that can accommodate a greater number of terminals within a limited band and can obtain a higher transmission rate. While the number of frequency signals (spectrums) output in parallel by performing a spread spectrum from the DFT unit of each terminal is 12, the number of sub-carriers constituting one sub-channel is set at 10 or 11. In this case, the users (users A and G) allocated to the sub-channels at both ends of the band will not perform transmission of one frequency signal at the end (one sub-carrier) of all the frequency signals output from the DFT unit, whereas the users (users B to F) allocated to the other sub-channels will not perform transmission of the frequency signals at the ends (two sub-carriers). This transmission can be realized by deleting (clipping) the associated number of signals from both ends or from one end of the frequency signals output from the DFT unit of each terminal and allocating the frequency signals after clipping, to individual sub-channels.

The invention relates to a visible light communication modulation method based on carrier index modulation and an implementation system thereof. The information bits to be transmitted are divided intotwo parts of index bits and constellation bits; the constellation bits are input into a unipolar M-order PAM constellation diagram to obtain a modulated constellation symbol; and then, every two constellation symbols form a complex signal. The index bits are used for selecting which sub-carriers to transmit the complex signal and which sub-carriers to transmit the conjugate signal of the complexsignal. After being subjected to discrete fourier inverse transform and direct-current offset, the complex signal modulated by the carrier index modulation can be converted into a unipolarity real signal. At a receiving end, the complex signal, obtained after the direct-current offset and the discrete fourier transform are removed, recovers the index bits according to the judgment of the symbol ofan imaginary part of the received signal. The received complex signal real part and imaginary part are respectively subjected to demapping of the M-order PAM constellation diagram to recover the transmission constellation bits.

The invention provides a mixed precode design method for an actual broadband large-scale MIMO system. The method comprises the following steps: at a radio frequency end, supposing analog precodes on all the carriers to be equal, and calculating an ideal analog precode matrix by taking maximizing the system spectral efficiency as a criterion and utilizing integrated channel state information; according to the phase shifter characteristic of an actual system, determining the analog precode matrix on each carrier in reality, designing a phase position correcting matrix in a digital domain, correcting phase position deviation of the analog precode on different carriers in reality to approach the ideal analog precode, multiplying the phase position correcting matrix by the analog precode matrix of the phase position deviation occurring on each carrier to obtain the designed analog precode matrix; and designing a digital precode matrix at the base band position by utilizing equivalent low-dimension channel state information, and multiplying by the obtained analog precode to obtain a mixed precode design scheme.

A joint scheduling apparatus and method for increasing frequency efficiency and fairness in a distributed antenna system using frequency reuse and common control power Packets are selected for transmission to be transmitted to MSs are selected, taking into account QoS in at least one of a BS and an RS and grouped into packet groups. The packets are selected from the packet groups, links corresponding to the packets are grouped into a link group, a joint power control is performed on the link group, link elimination and link addition are performed for the link group until optimal solutions are achieved for the links of the link group in the joint power control. Channels are allocated to the links when the optimal solutions are achieved for the links, and the status of a user queue of at least one of the BS and the RS is updated.

A base station apparatus provided with a function of performing communication using multiple beams implements appropriate beamforming while reducing interference power, thereby communication quality becomes stable and frequency efficiency or throughput is improved. The base station apparatus according to the present invention is a base station apparatus for communicating with a terminal apparatus, the base station apparatus including: a transmitter configured to transmit a synchronization signal block including a synchronization signal in a prescribed transmission window; and a controller configured to configure a size of the prescribed transmission window in which the synchronization signal block is transmitted, in which the transmitter notifies the terminal apparatus of information associated with QCL between two of the synchronization signal blocks transmitted in the prescribed transmission window.

Necessary transmission power of terminals is secured while suppressing total transmission power in base station, so that FFR technology is realized with high frequency utilization efficiency to thereby realize both of compactness of base station and increase of communication capacity. Frequency resource is divided into frequency for boundary area of cell and frequency for central area of cell. Transmission power per unit frequency is fixed in the frequency for boundary area of cell and is set to be variable in the frequency for central area of cell. Transmission power per unit frequency is adjusted so as to satisfy necessary power of terminals connected to frequency for central area of cell. When it is judged that total transmission power of base station exceeds prescribed value, terminal is moved from central area to boundary area of cell, so that total transmission power is suppressed to be equal to or smaller than standard.

Disclosed are a communication apparatus and a communication method capable of improving transmitting/receiving frequency efficiency of a satellite signal per bandwidth or spectral efficiency (S.E) per bandwidth by removing and improving a distortion or inter-symbol interference for applying a minimum-mean square error (MMSE) equalizer required to detect a frame synchronization and a modulation code rate in a satellite service for satellite broadcasting or communication under the variable coding and modulation (VCM) or adaptive coding and modulation (ACM) environment.

A base station apparatus, a terminal apparatus, and a communication method are provided in which reliability, frequency efficiency, or throughput can be improved in a case that transmission is performed based on beam forming. For a first CRI indicating a first CSI-RS resource and a second CRI indicating a second CSI-RS resource, the first and second CRIs being simultaneously receivable by the terminal apparatus, a first RI for the first CRI and a second RI for the second CRI are determined, and in a case that a total of the first RI and the second RI is four or less, a CQI determined by using both the first CRI and the second CRI is determined, and in a case that the total of the first RI and the second RI is greater than four, a first CQI determined by using the first CRI and a second CQI determined by using the second CRI are determined.

Provided are a base station apparatus, a terminal apparatus, and an integrated circuit, by which the terminal apparatus performing interference suppression and cancellation is able to efficiently suppress an interference signal. The base station apparatus of the invention is a base station apparatus that notifies a first terminal apparatus of terminal information which is information of a second terminal apparatus and which causes interference. The base station apparatus always transmits, to the terminal apparatus performing interference suppression, a coded bit sequence, which includes the large number of systematic bits, regardless of a state of retransmission request, and notifies the terminal information of an interference signal. The terminal apparatus suppresses the interference signal based on the terminal information, and detects a desired signal from the coded bit sequence.

The invention discloses a method for improving ultralow-power-consumption wireless communication transmission spectral efficiency. The method includes a step of O-QPSK (quadrature phase shift keying) for extension and a step of 16-aryorthogonalDSSS spread spectrum sequence for length reduction. By the method, transmission modulation modes of ultralow-power-consumption wireless communication physical layers are expanded, frequency efficiency is improved, and the data speed which is 8Mbit/s maximally can be provided through different combinations of modulation modes and spread spectrum sequences and is increased by 32 times as compared with the data speed which is 250Kbit/s maximally in a standard of 802.15.42450MHzPHY. The same power utilization rate as the modulation technology in an original standard is kept while transmission frequency efficiency is improved, original equipment complexity and power consumption can be maintained, and frequency spectrum resources can be completely used by ultralow-power-consumption wireless communication while cost and energy consumption are reduced.

The invention discloses a keying modulation method based on transmit diversity. According to the method, a transmit diversity mode is combined with traditional SSK modulation as the basis for transmission and receiving. Multiple time slots are adopted at an emission end to send the same data, different antenna mapping methods are adopted in different time slots, and meanwhile, different time slots activate sending symbol combinations of an antenna to bear a part of extra data information. Accordingly, the method is an SSK modulation transmission mode based on spatial diversity. Compared with traditional SSK, the diversity mode that the time slots send the same data is adopted, so that bit error rate performance of a system is improved. The system has high diversity gain due to the fact that different mapping modes are adopted in the time slots. Sending symbols on different time slots carry sending information, so that frequency efficiency of the system is further improved.