749 results about "Duplex system" patented technology

A duplex polarization adaptive system is described. The system provides polarization diversity for base station antennas under both receive and transmitting conditions. Since the base station provides polarization diversity in both transmit and receive modes, no polarization diversity is needed in the handheld unit. Even though the handheld unit does not provide polarization diversity, a duplex communication system, that uses polarization diversity for both the uplink and the downlink is provided, because the base station provides polarization diversity for the uplink and the downlink paths. By installing the two-way diversity at the base station, the overall cost of implementing diversity is reduced because one base station can typically serve many handsets. The base station antenna determines the polarization state of signals received from a remote unit, such as a handheld unit, using a polarization diverse antenna system. The base station then transmits using the same polarization state. The system is compatible with time-division duplex systems.

A communications apparatus used in a wireless full duplex system is disclosed. The communications apparatus includes a receiver chain connected to an antenna and an interference cancelling chain. One or more cancellation signals generated by the interference cancelling chain are fed back to the receiver chain prior to the first baseband amplifier which uses the first automatic gain control and the second automatic gain controller. Other methods and systems also are disclosed.

A method for determining the radio frame structure of a Time Division Duplex system is disclosed, which comprises: configuring, by the network side, the radio frame structure used for service transmission as containing two half-frames each of 5 ms, wherein each half-frame consists of eight service time slots of 0.5 ms and one special time slot field of 1 ms, two consecutive service time slots form a subframe of which the length is 1 ms, and the special time slot field contains a DwPTS, a GP and an UpPTS; determining the lengths of the DwPTS, the GP and the UpPTS in the special time slot field according to the requirements of the coverage range, and determining the radio frame structure used for service transmission. By reconfiguring the radio frame structure, the invention can flexibly support different coverage ranges, enhance the flexibility of satisfying different service requirements, and implement the coexistence of two types of TDD systems.

A transmitter/receiver for use in a multichannel time division duplexing system having an independent combiner and divider to isolate a transmission channel from a reception channel. The transmitter/receiver includes a first and second circulator connected, respectively, to a first and second transceiver. A transmission channel, formed between the first and second circulators and an antenna, transfers transmission signals from the first and second transceivers to the antenna in response to a transmission enable signal. A reception channel, formed between the first and second circulators and the antenna, transfers a reception signal from the antenna to the first and second transceiver in response to a reception enable signal. A switching control circuit is provided for generating the transmission enable signal during a transmission mode of operation and for generating the reception enable signal during a reception mode of operation.

The embodiment of the invention discloses a subframe configuration method, base station and user equipment in a time division duplex system. The method comprises the following steps of: determining subframe numbers of flexible subframes in a radio frame by the base station; determining the attributes of the flexible subframes corresponding to the subframe numbers by the base station; representing that the flexible subframes are uplink subframes or downlink subframes through the attributes; and sending a first signal from the base station to the user equipment through a downlink control channel, wherein the first signal comprises the attributes of the flexible subframes corresponding to the subframe numbers. By adopting the method, the base station and the user equipment, disclosed by the embodiment of the invention, the purpose of notifying the user equipment of the situation that the certain flexible subframe is the uplink subframe or downlink subframe by the base station can be realized, and the user equipment can perform normal communication with the base station under the situation of knowing the attributes of the flexible subframes.

A method for partitioning a soft buffer in a time-division duplex system and an apparatus using the same are disclosed. The method includes the following steps. A total number of soft channel bits, a maximum number of transport blocks transmittable to a user equipment (UE) in a transmission time interval (TTI), a maximum number of downlink (DL) hybrid automatic retransmit request (HARQ) processes, and a configured maximum number of HARQ processes are determined. A partition size of the soft buffer is selected according at least to the total number of soft channel bits, the maximum number of transport blocks transmittable to the UE in the TTI, the maximum number of DL HARQ processes, and the preconfigured maximum number of HARQ processes.

A full-duplex transceiver is provided with componentry and methods for cancellation of nonlinear self-interference signals. The transceiver is capable of receiving an incoming radio-frequency signal that includes both a desired radio-frequency signal component and a self-interference component caused by the transceiver's own radio-frequency transmission. The transceiver demodulates the incoming radio-frequency signal to generate a first demodulated signal. The transceiver combines an analog corrective signal with the first demodulated signal to generate a second demodulated signal with reduced self-interference. The transceiver processes the first and second demodulated signals to determine a desired incoming baseband signal and to determine nonlinear components of the self-interference signal, such as nonlinearities introduced by the transceiver's power amplifier.

Techniques are provided for reducing interference in a wireless network. A user equipment device in a first wireless coverage area of a wireless network using a time division duplex transmission scheme to designate a maximum timing advance value for uplink transmissions based on potential interference between uplink transmissions made by the user equipment device in the first wireless coverage area or at least one other user equipment device in the first wireless coverage area, and downlink transmissions intended for at least one user equipment device in a second wireless coverage area of the wireless network. The maximum timing advance value may be based on relative cell radii or other cell properties of the first and second wireless coverage areas. A base station may determine the maximum timing advance and transmit the maximum timing advance to the user equipment device.

Disclosed is a forward channel configuring method in an OFDMA FDD system. The method comprises: classifying the cells into a specific number of patterns based on location relations of the respective cells; allowing the respective base stations of the cells having different classified patterns to transmit control information to the mobile station at different times within a period of the forward channel, and allowing the respective base stations of the cells having the same classified patterns to transmit control information to the mobile station at the same time; and allowing the respective base stations to transmit traffic data to the mobile station irrespective of the classified patterns when the control information is transmitted.

Disclosed is a method and an apparatus for transmitting a downlink Synchronization CHannel (SCH) in an Orthogonal Frequency Division Multiplexing (OFDM)-based cellular wireless communication system supporting a scalable bandwidth. Herein, initial cell search and neighbor cell search are seamlessly performed. The disclosed method and apparatus disclose a synchronization channel structure applicable to both a Frequency Division Duplex (FDD) system and a Time Division Duplex (TDD) system.

Accordingly, a method and apparatus are provided wherein a receiver system selects a pre-coding matrix, comprising eigen-beamforming weights, to use and provides rank value and matrix index associated with the selected matrix to the transmitter system. The transmitter system upon receiving the rank value and matrix index, determine if the matrix associated with the matrix index provided by the receiver system can be used. If not, them transmitter system selects another matrix for determining eigen-beamforming weights.

The invention relates to the technical field of mobile communication, in particular to a subframe distribution technology for a time division duplex system. The invention embodiment discloses a method and a device for subframe distribution for the time division duplex system which reduces the time slot proportion regulation granularity and strengthens the flexibility satisfying different business requirements. The method for the subframe distribution for the time division duplex system comprises: according to proportion of an uplink business volume and a downlink business volume, determining configuration proportion of an uplink time slot and a downlink time slot when at least one wireless frame is taken as a subframe distribution period; according to the configuration proportion of the uplink time slot and the downlink time slot, determining a distribution mode of an uplink business subframe and a downlink business subframe in at least one wireless frame. The device for the subframe distribution for the time division duplex system comprises a configuration proportion determination unit and a first distribution mode determination unit. The invention embodiment also provides a base station and user equipment.

The invention discloses a time division duplex system, a dynamic frame structure based on the time division duplex (TDD) system and a configuration method. In a wireless frame, a subframe is selected as a dynamic subframe which has various states, and the states comprise an uplink subframe state, a downlink subframe state and an empty subframe state. In the time division duplex (TDD) system, when the adjacent boundaries of domains adopting different uplink and downlink configurations or the subdomain in the domain adopting certain uplink and downlink configuration changes the uplink and downlink configuration, the state of the dynamic subframe is adjusted so as to avoid the overlapping phenomenon of the uplink subframe and the downlink subframe of the adjacent cells adopting different uplink and downlink configurations, thus eliminating interference between the uplink subframe and the downlink subframe; and when a service type in certain subdomain is changed, the uplink and downlink configuration can be flexibly converted into other uplink and downlink configurations.

A method of defining physical channel transmit/receiving timings and resource allocation is provided for use in a Time Division Duplex (TDD) communication system supporting carrier aggregation. A method for receiving, at a base station, a Hybrid Automatic Repeat Request (HARQ) acknowledgement from a terminal in a Time Division Duplex (TDD) system supporting carrier aggregation of a primary cell and at least one secondary cell includes transmitting a downlink physical channel through one of the primary and secondary cells, receiving the HARQ acknowledgement corresponding to the downlink physical channel of the primary cell at a first timing predetermined for the primary cell, and receiving the HARQ acknowledgement corresponding to the downlink physical channel of the secondary cell at second timing, wherein the second timing is determined according to the first timing.

The invention provides a method and a device for sending physical uplink control signals in a time-division duplex system, the method comprises following steps: encoding the uplink control signals with a communication channel to obtain coded bits, modulating the coded bits with QPSK to obtain modulation symbols, transforming the modulation symbols with DFT to obtain symbols on a frequency domain,expanding the symbols on the frequency domain with time-domain through adopting a CAZAC root sequence to respectively obtain a first signal and a second signal which are sent on two time slots, mapping the first signal and the second signal on an information symbol which is corresponded with a PUCCH reference signal structure 2, and combining the information symbol and the reference signal into asignal which will be sent by a sub-frame. The invention can well satisfy the performance requirement and the covering requirement that a plurality of ACK/NACK can be sent on an uplink sub frame.

The invention discloses a hybrid automatic repeat method for a time division duplex system. The method ensures that the TTI numbers of an uplink and a downlink are the same by setting the length and the number of TTI in a frame structure, thus establishing the one-to-one corresponding relationship between TTI of the uplink and the downlink, so that in the HARQ transmission process, fixed relationship can exist among the feedback of ACK/NACK, HARQ process id and TTI. The feedback of ACK/NACK and HARQ process id can be easily determined by TTI, thus reducing the complexity of realizing the TDD system design of HARQ effectively.

The invention discloses a wireless frame of a mobile communication system and a sending method of a measurement reference signal. A terminal transmits a measurement reference signal to a base station on a time frequency source corresponding to a protective zone in the wireless frame, wherein, the protective zone is one or more of a descending to an ascending protective zone, an ascending to a descending protective zone, a pre-reserved subframe or a pre-reserved idle resource. In a time division duplex system, the protective zone is a frequency division resource corresponding to the protective interval of a specific subframe or an ascending pilot frequency time slot or is an ascending time slot newly added in the specific subframe, and the terminal transmits the measurement reference signal on a time frequency source corresponding to the protective interval of the specific subframe or the ascending pilot frequency time slot or the ascending time slot. In a frequency division duplex system, the protective zone is a pre-reserved subframe or a symbol resource pre-reserved in the subframe. In the invention, the time frequency source for transmitting reference signals is added to meet the transmission requirements for measuring the reference signal of more users.

The invention discloses a co-channel full-duplex system based on MPPSK modulation. After the system isolates receiving and sending signals at the radio-frequency head normally, cancellation conducted on leakage self-interference signals is finished on a digital baseband; the cancellation method is conducted after conducting shock filter on MPPSK receiving and sending aliasing signals, extracting and multiplying by coherent carrier, band-pass filtering and digitizing, the result of initial channels of all self-interference channels between the output end of a modulator and a receiver ADC is estimated before formal communication, self-interference offset signals are rebuilt by the adoption of the estimated result, further residual errors are filtered out with the combination of methods of coding rate filtering and double matched filtering of a method of shock filtering-multiplying by the coherent carrier-band-pass filtering-coherent demodulation, and MPPSK receiving signals are demodulated reliably. The co-channel full-duplex system based on MPPSK modulation is free of radio-frequency self-interference cancellation, has low requirements for the dynamic range and sampling rate of the ADC, has high isolation degree for the self-interference signals, and is simple in structure, low in complexity, high in spectrum efficiency and good in demodulation performance.

A method for data transmission in a TDD system is disclosed. The method includes: configuring, by a base station, a length respectively for a Downlink Pilot Slot (DwPTS) and an Uplink Pilot Slot (UpPTS) within a special field of a radio half-frame based on a current coverage area taking one Orthogonal Frequency Division Multiplexing (OFDM) symbol as a unit, and issuing a configured result to a user device, wherein a total length of the DwPTS, a Guard Period (GP) slot and the UpPTS is kept to be 1 ms; constructing, by the base station, radio half-frames for data transmission according to the configured result. An apparatus for data transmission in the TDD system is also disclosed. According to the present invention, coverage area of different levels with smaller granularity is supported, radio resources are saved and transmission efficiency is increased.

An apparatus and method enable a full duplex system with self-interference cancellation. Receiving circuitry forming a signal receiving path is arranged for transferring communication signals received via air interface. Transmitting circuitry forming a signal transmission path is arranged for transferring communication signals to be transmitted via air interface. Interference cancellation circuitry is in operable connection between the signal receiving path and the signal transmission path. The receiving circuitry and the transmitting circuitry are arranged to receive and transmit communication signals at the same time and at the same frequency. The interference cancellation circuitry comprises resistance, inductance and capacitance arranged to constitute a center frequency of an isolation range between the signal receiving path and the signal transmission path which substantially falls into the center of a communication band for the signals received and/or to be transmitted via air interface.

The invention provides a frame structure of a time division duplex system and a method for sending synchronous signals. The method comprises that: a base station sends a main synchronous signal and an auxiliary synchronous signal on last two orthogonal frequency division multiplexing signals of a same downlink time slot of each half frame respectively, and the time slot is different from the timeslot for sending the main synchronous signal and the auxiliary synchronous signal in a frequency division duplex system; and the base station also sends a main physical broadcast channel of system broadcast information on continuous multiple orthogonal frequency division multiplexing signals of a downlink time slot of any half frame of the half frame, and the time slot of the main physical broadcast channel for sending the system broadcast information is on a same subframe as the time slot for sending the main synchronous signal and the auxiliary synchronous signal in the half frame. By usingthe frame structure and the method, under the condition that a double-mode terminal detects out a duplex mode in advance, the search performance of a cell can be improved; and according to the size of a time domain interval from the synchronous signals to the physical broadcast channel, the method can easily help the double-mode terminal to detect the duplex mode.

A technique for steering a directional antenna such as may be used with User Equipment (UE) in a wireless communication system. Optimum angle settings for the directional antenna are determined as different values for an uplink and downlink; that is for simple reception and simple transmission. Thus, rather than determine compromised directions that are picked in an attempt to optimize transmission and reception with the same directional setting, directional settings may be optimized independently. The invention is of particular use in a Time Division Duplex (TDD) system where transmit and receive functions can be operating independently at different times. In further aspects, an optimum direction is determined by estimating an interference signal power which is detected from signals emanating from adjacent base stations (access points) and determining a directional setting that minimizes interference to adjacent cells based upon such measurements. A further level of sophistication in antenna angle setting, is to monitor the loading of adjacent cell sites base stations and turning interference and determine the settings accordingly to minimize interference to such heavily loaded neighbors. Further aspects of the invention adapts to acquisition modes that accommodate the directional setting in active use of the system.

The invention provides a method and a system for reporting channel information in a TDD system. The method comprises the following steps: sending an RRC signaling to UE by a base station, and instructing the UE to report configuration of a periodic sub-frame offset position of the channel information in a physical uplink control channel (PUCCH); the RRC signaling comprises: periodically reporting a periodic sub-frame offset position parameter of channel quality information (CQI) of broadband or a pre-coding matrix instruction (PMI) in the PUCCH, periodically reporting a periodic sub-frame offset position parameter of CQI of sub-band or the PMI in the PUCCH, and periodically reporting a periodic sub-frame offset position parameter of a rank instruction (RI) in the PUCCH; the length of the parameter is determined by the structural configuration of a TDD frame; a mode comprises: determining the possibility number of the periodic sub-frame offset position according to the structural configuration of the TDD frame, then, determining the length of the parameter, and reporting the parameter in the PUCCH by the UE according to the configuration. The method and the system can save the signaling expense of the TDD system to allow the information exchange expense of the TDD system to be closer to that of an FDD system and improve the compatibility of two systems.

The utility model provides a interference clearance technique, so that the up-down-going link of the wireless communication can run via the same frequency and the time-slot, so as to improve the rate of spectrum utilization. When the up-down-going channel is under the common frequency and the time-slot, the down link will interfere the up-link, namely, the base station receiver in the sub-zone is interfered by the base station transmitter of the sub-zone and the base station transmitter of the adjoining sub-zone. The utility model delivers the undesired signals to the receiver through the wired communication. The receiver is arranged with a signal preprocessing unit, so as to remove the transmitter signal interference in the radio frequency. Such signal interference is from the air interface. In addition, the utility model provides an aerial distribution rule to reduce the direct interference of the transmitter to the receiver. The interference clearance method is suitable to the duplex system with the common frequency and time-slot, so as to greatly reduce the frequency resources and time resources.