Abstract:
PURPOSE: An apparatus and a method for allocating sub-channels in a communication system using an OFDMA(Orthogonal Frequency Division Multiple Access) are provided to maximize efficiency of cell searching and channel estimation by constructing some of allocated sub-channels as pilot channels. CONSTITUTION: Sub-carrier bands are classified at a pre-set interval to generate the same number of sub-carrier groups as the number of base stations. Sub-carrier bands are detected from each group corresponding to a sequence previously set according to certain controlling with respect to a specific base station. The detected sub-carrier bands are allocated as sub-channels with respect to the specific base station.
Abstract:
PURPOSE: An apparatus and method for transmitting RPC(Reverse Power Control) channels in a mobile system supporting an HDR(High Data Rate) system is provided to solve a delay problem in applying RPC channels and to transmit two different RPC channels a slot. CONSTITUTION: An encoder(607) encodes and outputs data traffic channel data. A modulator(609) executes QPSK(Quadrature Phase Shift Keying) for the output of the encoder(607) and outputs I/Q signals. An interleaver(611) interleaves and outputs the output of the modulator(609). A puncture/repeat unit(613) punctures and repeats the output of the interleaver(611) according to a given pattern. A demultiplexer(615) demultiplexes and outputs the output of the puncture/repeat unit(613). An orthogonal spreader(617) multiplies the output of the demultiplexer(615) by a 16-long orthogonal code for orthogonal spreading. A repeater(623) repeats preamble data given times and outputs the data. A multiplier(625) executes orthogonal spreading by multiplying the output of the repeater(623) by a given orthogonal code and outputs a preamble signal. A multiplexer(619) executes time division multiplexing for the data traffic channel signal from the orthogonal spreader(617) and the preamble signal from the multiplier(625).
Abstract:
PURPOSE: A forward link data service apparatus and method of a handoff terminal of a CDMA system are provided to improve a reception detection performance and heighten a data transfer rate by reducing an influence of an interference signal between sectors belonging to an active set through scheduling between sectors belonging to the active set. CONSTITUTION: When a terminal 'A' is selected(511), an alpha sector scheduler checks whether itself can transmits a packet by using a data received from an arbiter of a memory storing an idle sector(513). If the alpha sector scheduler recognizes that itself has not been stored through the arbiter of the memory storing the idle sectors, the alpha sector scheduler observes an active set of the terminal 'A' that itself is going to do a service(517). If there is a different sector in the active set of the terminal, the alpha sector scheduler requests an idle sector registration from the arbiter of the memory storing the idle sector. The memory arbiter updates the idle sector according to the idle sector registration request of the alpha sector scheduler(519). The memory arbiter informs each sector scheduler of the data on the updating of the idle sector. When the alpha sector scheduler receives the update data, the alpha sector scheduler transmits a packet data to the terminal 'A'(521). When the packet is completely transmitted, the arbiter of the idle sector memory deletes other sector values of the active set remembered before transmitting the packet stored in the idle sector region(523).
Abstract:
PURPOSE: A method and apparatus for selectively requesting packet retransmission in a mobile system is provided to improve the throughput by increasing a channel adaptation speed in a link adaptation method and an ARQ(Automatic Repeat reQuest) method used in a mobile system. CONSTITUTION: A terminal searches a preamble every time a time slot is received and confirms whether a packet is received from a base station(S310). If a packet is received, the terminal checks the length of the preamble in order to confirm whether the received packet has a low data transfer rate(S320). In case that the packet has a low data transfer rate, the terminal measures a pilot C/I(Carrier to Interference ratio) value for a forward pilot channel or a forward pilot symbol corresponding to the time slot interval at which the present packet was transmitted(S330). The measured pilot C/I value is compared with the first threshold(S340). In case that the pilot C/I value is larger than the first threshold, the terminal decodes the present packet and checks an error through the CRC(Cyclic Redundancy Check)(S350). In case that there is no error(S360), the terminal transmits an ACK signal to the base station(S370).
Abstract:
본 발명은 음성과 데이터 서비스를 위한 부호분할 다중접속시스템에서 올바른 기지국을 선택하고 최적의 데이터 전송율을 결정하기 위한 방법과 장치에 관한 것이다. 이를 위하여 본 발명은 기지국이 서로 다른 직교부호로 직교확산된 두 파일롯신호의 전력의 비를 음성의 부하와 관련이 있도록 전송하고, 단말기가 상기 전송된 파일롯신호를 이용하여 음성서비스의 부하량을 추정한다.
Abstract:
본 발명은 직교 주파수 분할 다중 방식을 사용하는 통신 시스템에서 단말(MSS)과 기지국 간에 서브캐리어들에 대한 채널 품질 정보(CQI)를 송수신하는 방법 및 장치에 관한 것이다. 단말은 미리 설정된 개수의 인접하는 서브캐리어들로 이루어진 밴드들 각각에 대해 채널 품질 정보(CQI) 값들을 측정하고, 상기 CQI 측정값들에 상응하여 적어도 2개의 밴드들을 선택하며, 상기 선택된 밴드들에 대한 CQI 측정값들의 변동을 나타내는 차등 CQI에 대한 정보를 기지국으로 전송한다. 이러한 본 발명은, 최소의 시그널링 오버헤드를 가지면서도 매 프레임마다 실시간으로 CQI가 반영되도록 한다. CQICH, 서브 채널 할당, 밴드, 전역 CQI, 차등 CQI
Abstract:
본 발명은 통신 시스템에서 상향링크 스케줄링을 위한 장치 및 방법에 관한 것으로서, 이러한 본 발명은 통신 시스템에서 상향링크 스케줄링 방법에 있어서, 각 이동 단말기별 스케줄링 메트릭을 계산하는 과정과, 상기 계산된 스케줄링 메트릭에 상응하여 우선순위가 높은 이동 단말기를 선택하는 과정과, 상기 선택한 이동 단말기에 대하여 소정의 입력변수에 따라 서브채널 수 및 변조 차수와 코딩율의 곱(MPR)을 추출하는 과정과, 상기 MPR에 상응하여 상기 선택한 이동 단말기에 대해 할당할 서브채널 수를 결정하여 할당하는 과정과, 상기 선택한 이동 단말기에 대한 서브채널 할당 후 상기 각 이동 단말기별 스케줄링 메트릭을 갱신하는 과정을 포함한다. OFDMA, TDD, 상향링크(uplink), 하향링크(downlink), 스케줄링