2227results about How to "Improve spectral efficiency" patented technology

The evolution of high rate data services within future wireless networks will call for new RF access technologies to enable substantial increases in overall system spectral efficiency at an acceptably low cost to the user. Space-Time Coding (STC) is an antenna array processing technology currently simulating considerable Interest across the wireless industry. The invention provides a space-time coding apparatus having an input, a trellis encoder, a modulator, a demultiplexer, and a set of signal outputs wherein the input is operable to receive a stream of data. This allows de-multiplexing to take place after coding and modulation has been performed. The trellis encoder comprises a convolutional encoder operable to sequentially group data to provide coded bits to provide QPSK symbols. By the selection of convolutional encoder rates and/or modulation alphabets STCs of any desired dimensionality may be produced including multi-dimensional codes.

In a multicarrier modulation communication system, subcarriers are allocated to a plurality of users using a plurality of sets of sequential subcarriers. The plurality of sets of sequential subcarriers may be allocated for transmitting information to the plurality of users or for transmitting information from the plurality of users. A multicarrier modulation communication system and the multicarrier modulation communications device is also discussed.

An uplink and downlink channel structure supports a shared downlink data channel. The new structure accommodates advanced physical and Medium Access Control (MAC) layer techniques, such as incremental redundancy (IR), fast adaptation to channel conditions, and multiple input multiple output (MIMO) antenna configuration. The proposed changes are intended to lead to a downlink structure that achieves higher spectral efficiency for the packet oriented services over then shared downlink channel. Additionally, the new structure uses the base station transmit power information and of the channelization (OVSF) code space more efficiently.

A system and method for managing licensed and unlicensed frequency bands in a wireless wide-area network includes establishing the available channels of a licensed band and unlicensed band of frequencies. Data traffic is prioritized for assigning channels. Higher priority data traffic is assigned to the licensed frequency band and lower priority data traffic is assigned to the unlicensed frequency band. Channel quality is determined, wherein higher priority traffic is assigned to lower noise channels. Data traffic is shifted from the channels of the unlicensed frequency band to the channels of the licensed frequency band if the quality of the channels of the unlicensed frequency band deteriorates below a predetermined acceptable threshold.

The present disclosure relates to a communication technique for combining a 5G communication system for supporting a higher data transmission rate than a 4G system with an IoT technology, and a system therefor. The present disclosure can be applied to 5G communication and IoT related technology-based intelligent services (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, health care, digital education, retail business, security and safety related services, etc.). Disclosed is a technology for adding uplink data to a radio resource control (RRC) connection request message corresponding to an RA response message and transmitting the same to a base station when the terminal is in an RRC deactivated state in a method for transmitting, by a terminal, uplink data in a wireless communication system.

The present invention provides for a communication system and method that overlays signals which are simultaneously mutually orthogonal in both the time and frequency domains, thereby enhancing spectral efficiency. Whereas commonly used sinusoids provide only two mutually orthogonal functions (sine and cosine), certain polynomials provide multiple orthogonal functions, which are also finite in both time and frequency. Using multiple orders of the orthogonal functions allows overlaying signals within a symbol to generate a modulated signal carrying more information than with traditional QAM. Correlating a received signal with locally generated replicas of the orthogonal functions allows demodulation of the signal. This modulation is applicable to twisted pair, cable, fiber, satellite, broadcast and all types of wireless access. The method and system are compatible with many current and future multiple access systems, including EV-DO, UMB, WiMax, WCDMA (with or without MBMS/MIMO), HSPA Evolution, and LTE.

A computationally efficient pulse shaping method for OFDM that produces mutually orthogonal transmission pulses having fast spectral decay is provided. The pulse shaping method comprises an iterative method for designing OFDM transmission pulses that satisfy prescribed time-frequency localization conditions. The iterative method may be implemented in a computationally efficient way and can be used to adapt the transmission pulses to time-varying channel conditions in real-time, thereby maximizing the bit-error performance of an OFDM system while maintaining high data rates in wireless transmission.

A method of transmitting a sounding reference signal includes generating a physical uplink control channel (PUCCH) carrying uplink control information on a subframe, the subframe comprising a plurality of SC-FDMA(single carrier-frequency division multiple access) symbols, wherein the uplink control information is punctured on one SC-FDMA symbol in the subframe, and transmitting simultaneously the uplink control information on the PUCCH and a sounding reference signal on the punctured SC-FDMA symbol. The uplink control information and the sounding reference signal can be simultaneously transmitted without affecting a single carrier characteristic.

A transmitter transmits payload data using Orthogonal Frequency Division Multiplexed (OFDM) symbols. The first OFDM symbol is a first type having a number of sub-carriers which is less than or equal to the number of sub-carriers of the one or more second OFDM symbols of a second type and a guard interval for the first OFDM symbol is selected in dependence upon the longest possible guard interval of the second OFDM symbol. Accordingly an OFDM communications system can be formed in which data is transmitted using a frame structure in which a guard interval is adapted to allow a mix of different types of OFDM symbols.

The invention discloses a method for feeding back HARQ, which comprises that: a sending end sends data to one or more receiving ends; a feedback mode of the receiving ends for feedback information ofthe data and/or parameters related to the feedback mode are determined according to channel characteristics, and are notified to the receiving ends. By means of the technical scheme, the feedback modeof the data is determined through the channel characteristics to reduce resources occupied by feedback channels and improve feedback efficiency and spectral efficiency of a wireless communication system.

A prior art MIMO technique assumes one-to-one communication in which a transmitter and a receiver exist and does not assume a cellular system in which plural access points and access terminals exist. When the prior art is applied to the cellular system, the characteristic can be deteriorated. MIMO signal processing is not performed in access points. Signal processing units in the access points are integrated into an access point controller controlling plural access points and the MIMO signal processing for plural access points is performed together.

A system and method for transporting encrypted data having a transmitter and a receiver is provided. The transmitter generates a sequence of optical pulses, which are copied and output as identical channels. The identical channels are modulated by a plurality of modulators using data to generate a modulated data signal. Respective spectral phase encoders coupled to each of the plurality of data modulators encode respective modulated data signals using a plurality of mutually orthogonal phase codes that are individually associated with the respective spectral phase encoder. These encoded data signals are combined and code-scrambling by a spectral phase scrambler t using a scramble code as an encryption key to generate an encrypted signal. A receiver reverses the encryption to extract the data.

The invention discloses a method and a device for channel state information processing in order to solve the problem that measurement and feedback of UE cannot adapt to all kinds of transmission modes in the prior art. The method comprises the following steps: UE receives high-level configuration information which is from a base station and indicates one or two CSI-RS resources; the UE receives a corresponding CSI-RS signal according to the high-level configuration information and carries out channel measurement to obtain a channel measurement result; and the UE determines and reports a CSI according to the channel measurement result of the CSI-RS signal, wherein the CSI at least includes a combined CQI which is calculated according to two pre-coding matrixes, and the two pre-coding matrixes are measured according to the CSI-RS signal of one base station. The device comprises a configuration information receiving module, a channel measuring module and a CSI processing module. By the adoption of the technical scheme of the invention, the capacity and spectrum efficiency of the existing system are greatly improved.

The invention provides a lighting unit comprising a source of blue light, a source of green light, a first source of red light comprising a first red luminescent material, configured to provide red light with a broad band spectral light distribution, and a second source of red light comprising a second red luminescent material, configured to provide red light with a spectral light distribution comprising one or more red emission lines. Especially, the first red luminescent material comprises (Mg,Ca,Sr)AlSiN₃:Eu and/or (Ba,Sr,Ca)₂Si_5-xAl_xO_xN_8-x:Eu, and the second red luminescent material comprises K₂SiF₆:Mn.

The invention discloses a method of an extensible OFDM and OFDMA bandwidth distribution, which has the advantages of improved spectrum efficiency and enhanced flexibility and adaptability owing to the extensible single or multi-carrier bandwidth distribution characteristics. The invention also discloses a transmitter and a system of the spectrum bandwidth distribution in the OFDM and OFDMA system. The protection of the band and the sub-carrier can be reduced or deleted so as to improve the spectrum efficiency and the invention has bandwidth expandability.

A resonator structure includes an input waveguide and an output waveguide. In one embodiment, the resonator structure also includes at least one resonator that couples the input waveguide to the output waveguide and a directional coupler that optically couples the input waveguide to the output waveguide. In another embodiment, the resonator structure includes a plurality of ring resonators that couple the input waveguide to the output waveguide. The plurality of ring resonators include a sequence of ring resonators that form a coupling loop. Each ring resonator in the sequence is coupled to at least two other ring resonators in the sequence and the first ring resonator in the sequence is coupled to the last ring resonator in the sequence so as to form the coupling loop.

The invention provides a technical scheme applied in a cellular network of mobile communication, which applies a device-to-device (D2D) technology in the cellular network, and allows D2D user pairs to multiplex resources of cellular network users for communication. The invention provides a method based on base station positioning to select the cellular users for the D2D user pairs for multiplexing resources and selects the cellular user having the farthest distance away from each pair of D2D users to carry out resource multiplexing. In the scheme provided by the invention, the complexity of an algorithm through which a base station end selects the cellular users for resource multiplexing is simplified, and the interference between the D2D user pairs for multiplexing resources and the cellular users is reduced to be lowest, so that the whole frequency spectrum efficiency of the system is improved. In addition, for the method, the practical operability is very strong, the implementation is easy in practice, and the application modes are more flexible.

The invention discloses a resource scheduling method and device and a base station which are used for lowering the signaling overhead of downlink control channel instructions in uplink and downlink data transmission. The method comprises the following steps: when the judging result shows that the cell of a user terminal is an interference limited cell and a semi-persistent scheduling mechanism needs to be set for the user terminal, configuring semi-persistent scheduling parameters for the user terminal; when the determining result shows that the user terminal needs to adopt the semi-persistent scheduling mechanism to transmit the service data of the access service, allocating semi-persistent scheduling resources for transmitting the service data to the user terminal according to the semi-persistent scheduling parameters; and sending the resource scheduling information of the semi-persistent scheduling resources to the user terminal through the downlink control channel of the user terminal. By adopting the technical scheme of the invention, the signaling overhead of the downlink control channel instructions in data transmission is lowered, the inter-cell interference of the downlink control channel is reduced, and the receptivity of the downlink control channel and the QoS (Quality of Service) and cell spectrum efficiency of users are improved.