China Academy of Telecommunications Technology

Datang Mobile Communications Equipment Co., Ltd.

Huawei Technologies Co., Limited

Cwill Telecommunication, Inc.

Shihe Li

Feng Li

Guiliang Yang

Jun Li

Guanghan Xu

Tiezhu Xu

Jinling Hu

Liwei Wang

Dongyan Wang

Yusong He

Ying Chen

Wei Chen

Xian Liu

Hongbo Wang

Wensheng Xu

Yucong Gu

Peiwei Wang

Hua E

Xiaozhou Chen

Guoxin Zhao

Jianfeng Wu

A method for distributing wireless resource in multicarrier time division duplexing mobile communication system, such as TD-CDMA system, to overcome the shortage of 3GPP single carrier cell channel distribution technology of covering more lager area in composing cellular system, which contains using an area of covering same or almost same as a cell, selecting one carrier as main carrier and other carriers as auxiliary carrier, the frequency of main carrier is as different as possible, setting all public control channel in main carrier, the left resource of main carrier and resource of auxiliary carrier are used in uplink and downlink service channel, the arrangement of public channel in main carrier is same with that in single carrier cell.

Method for allocating radio resource in multi-carrier time division duplex mobile communication system

The present invention discloses a baseband chip and a method to implement multi-mode switching for a mobile terminal based on the baseband chip, the baseband chip of the mobile terminal in the present invention includes three subsystems of a source encoding/decoding subsystem, a wireless transmitting/receiving subsystem, a wireless transmitting/receiving and source encoding/decoding common control and process subsystem, the baseband chip may be implemented by using a single chip based on CMOS technology. The baseband chip of the present invention are suitably used to a TD-SCDMA mode mobile terminal or a multi-mode mobile terminal including TD-SCDMA, the new requirements proposed to the mobile terminal of the third generation mobile communication technology are met, and repeated design are decreased; furthermore, the method of switching among different communication modes for the mobile terminal based on the above mentioned baseband chip in the present invention implements the switching among different communication modes for the mobile terminal.

Baseband chip and method to implement multi-mode switching for mobile terminal based on baseband chip

A method to support dissymmetry service for multicarrier time division duplexing mobile communication system, which contains adopting different uplink and downlink time gap conversion point to support dissymmetry service among multicarrier frequency of different cells and same cell, when the original configured uplink and downlink time gap ratio can not support the service request, then changing the time gap ratio to receiving said request, adjusting service to avoid interference by quick dynamic channel distribution technology, in ending request service, changing time gap ratio in original ratio. Said invention supports different uplink and downlink time gap conversion point, the base station equipment needs establishing isolated uplink and downlink.

Method for supporting asymmetric service flexible in multi-carrier time division duplex mobile communication system

The present invention provides a method of wireless transmission using a high-efficiency and high-performance frame structure used by the broadband TDD system, wherein the method includes: dividing a sub-frame with a fixed length into N+1 basic slots and three special slots, wherein one basic slot is used to transmit broadcast or paging information of a cell and N basic slots are used to transmit service information in the downlink and uplink; combining several basic slots in the N basic slots to a spreading slot when a transmitting rate of a single slot needs to be improved and using the spreading slot to transmit and spread high rate services with a matching slot length. The present invention proposes a developing direction for the TDD system in the beyond 3G. With this frame structure to perform the wireless transmission, services at different data rates can be provided and the ability of transmitting at different rates up to 100 Mbps when the system bandwidth is 5 MHz, 10 MHz or 20 MHz respectively only by changing the length of the slot, combining basic slots into different multiples of spreading slots, adopting different modulation mode and spreading coefficient.

Wireless transmission method of using efficient high performance frame structure in wideband TDD system

The present invention discloses a base station system, including an indoor part and a remote RF subsystem (RRS). The indoor part includes a RIU, a CCU, a BBU, a GPSU and a local interface unit. The RRS includes a remote interface unit, a RF transceiver unit (TRU) and an antenna. The local interface unit and the remote interface unit are for signal intercommunicating between the indoor part of the base station and the RSS. The TRU is a RF transceiver module of the conventional RFU, for amplifying an analog RF signal from the remote interface unit and transmitting the signal to the antenna. By flexibly selecting between an optical cable and an If cable, the interface unit of the present invention provides a digital baseband remote manner and an IF remote manner. According to the structure of the base station of the present invention, the number of the base station sites and the network operating cost decreases; on the other side, since one base station may cover a cell by smart antenna with only one optical cable or IF cable, the difficulty in mounting is reduced.

Base station system

The present invention discloses a method for improving the performance of the CDMA TDD wireless communication system. It is a method for increasing the transmission rate in a multi-slot CDMA system. The method comprises combining a plurality of neighboring time slots to form a combined time slot with a length of integer times of the length of the original time slot, wherein the modulation modes adopted by the combined time slot are not limited, and transmitting traffic data with at least one service data field in the combined time slot, and using the guard period in the combined time slot for guard between combined time slots.

Method for improving the transmission speed in multi-slot CDMA wireless communication system

The present invention discloses a gain control method used at the initial cell searching by the user terminal in TD-SCDMA mobile communication system. At each carrier frequency, the user terminal firstly receives and records the data of a plurality of subframes transmitted from a base station when the receiver is set at the maximum gain; searchs the DwPTS positions by using the time window decision method; performs the succeeding steps of the initial cell searching subsequently when the DwPTS positions can be obtained; judges whether the receiver is in saturation when the DwPTS positions can not be obtained; decreases the receiver gain by a large step and receives and records the data of a plurality of subframes transmitted from the base station if the receiver is in saturation; and determines that there is no base station for working at the present carrier frequency if the receiver is not in saturation. The above initial cell searching procedures are repeated until the receiver is not in saturation any more. The ADC of user terminals can finish the initial cell searching under the condition of less dynamic range by using the present invention.

Gain control method for the initial cell searching in TD-SCDMA mobile communication system

The invention relates to a method and an apparatus using smart antennas in a frequency division duplex code division multiple access mobile communication system and for solving the limitations of smart antenna use due to asymmetric propagation of uplink electric wave and downlink electric wave. In the wireless base station, there are transmitting and receiving smart antenna arrays and associated transmitters and receivers, respectively, and a common baseband signal processor. In the method, the main path direction is determined by signal direction of arrival, obtained from receiving signal; in the downlink beam forming, an expected transmitting beam form is based on the main path direction. The system can obtain advantages of smart antenna, improve cell coverage, increase system capacity and reduce cost.

Apparatus and method using smart antenna in FDD wireless communication system

The invention discloses a method for transmitting high-speed downlink package data in a mobile communication system with a smart antenna, which not only can take full advantage of radio beamforming of smart antenna but also can transmit downlink package data high efficiency. In this method, at the beginning of downlink package data transmission, no matter whether a subscriber terminal is at any state, a call for all ready subscriber terminal is made through a paging channel to obtain an initial DOA (direction of arrival) of every subscriber terminal, and then with this initial DOA the smart antenna transmits downlink package data to a subscriber terminal with an initial beamforming; having received one package, the subscriber terminal returns an acknowledgement message, if the downlink package is correctly received, or retransmission is required, if the received downlink package has error codes, so the system knows current position of the subscriber terminal and can use an updated beamforming to trace the subscriber terminal moving; based on received package quality, the system adaptively adjusts the length of a downlink package, and based on the moving speed of the subscriber terminal, the system adaptively adjusts the length of the downlink package too.

Method of mobile communication system with smart antenna

A real-time calibration method for a smart antenna array. The method includes: before installation, a smart antenna array is pre-calibrated to obtain transmission-coefficient matrix between antenna units; after installation at site, the pre-calibrated transmission-coefficient matrix is loaded in a base station to which the smart antenna array connects; during running, every transmission link of the base station transmits a unit calibration signal in sequence in a time-slot, and all other links, except the transmitting link, are in a reception state to receive the unit calibration signal, and the received unit calibration signals are recorded; with the received unit calibration signals and pre-calibrated transmission-coefficient matrix, the smart antenna array is calibrated. The method does not need beacon antenna, coupled structure of the antenna array and a special calibration link.

Method for calibrating smart antenna array in real time

A distributed smart antenna system including an antenna array having N antenna elements, N radio frequency tranceivers, and feeder cables connecting both. N antenna elements and N radio frequency transceivers are grouped according to cell coverage range and traffic volume. Antenna element groups are then distributed at different places of coverage within the range of the same wireless communication system base station, including different buildings or different floors of same building; however, the same baseband digital signal processor is used. Each antenna element group can have one to M antenna elements. The system enables improved cell coverage, increased system capacity, and decreased system cost.

Distributed smart antenna system

This invention discloses an interference cancellation method based on smart antenna, which can solve various interference in mobile communication systems such as multipath propagation, etc., while using smart antenna. The invention includes the steps of: with a beam forming matrix, beam forming the output signal of a receiver based on smart antenna, then getting a set of digital signals NR (m); canceling other users main path signal included in NR (m), then getting another set of digital signals NS (m), which only includes needed signals and all interference signals; searching in digital signal NS (m) and getting all multipath interference signals coming from other users; canceling other multipath interference signal in NS (m); and superposing the user main path and each multipath signal in phase coincidence, then getting a digital signal with interference canceled.

Method of interference cancellation based on smart antenna

This invention discloses a method and a device for calibrating smart antenna arrays in real time. The invention includes the steps of providing a calibrating link comprising a coupling structure, feeder cables and pilot transceiver; pre-calibrating the coupling structure with a vector network analyzer and recording its receiving and transmitting transmission coefficients, respectively; implementing the receiving calibration to a smart antenna array by adjusting the transmission coefficient of each receiving link and a reference link to the same amplitude and phase difference &PHgr;, which is recorded and stored in a baseband processor; and implementing the transmitting calibration by adjusting the transmission coefficient of each transmitting link and a reference link to the same amplitude and phase difference &PSgr;, which is recorded and stored in the baseband processor. The coupling structure of the invention is implemented by a pilot antenna using spatial couple mode or a passive network.

Method and device for calibrating smart antenna array

A wireless communication system has a protocol enabling synchronous code division multiple access (CDMA) communication on a time division duplex (TDD) frequency, and provides for a smart antenna system as an integral component of the system. The protocol has downlink time slots (DTS) which provide for synchronization and paging of all remote terminals from a base station on a omnidirectional code channel and while providing for traffic signals on directional traffic channels. The protocol has uplink time slots (DTS) which enable rapid link requests by remote terminals, as well as enabling improved spacial estimation, synchronization and power control of remote terminals by the base station.

Growing community of inventors

Beijing, China

Shihe Li