Abstract:
PURPOSE: A handover method of a terminal and a terminal thereof eliminates a handover interruption time for the handover process of the terminal. In that way the communications service of the high quality is realized. CONSTITUTION: An MS(Mobile Station) transmits a handoff request message in the serving base station(S411). The target base station transmits the handover response message with the serving base station(S415). The terminal receives a message the handover response message from the serving base station. The terminal transmits and receives the serving base station and data with the first carrier(S418). The terminal is proceed the target base station and hand over signaling procedure with the second carrier wave(S422~S429).
Abstract:
PURPOSE: A method and an apparatus for controlling retransmission are provided to retransmit HARQ bust in case of failure of HARQ bust transmission by mixing synchronous an HARQ(Hybrid Automatic Repeat reQuest) and asynchronous HARQ properly. CONSTITUTION: In a method and an apparatus for controlling retransmission, a retransmission control apparatus(100) is composed of a retransmission decision unit(110), a transmission unit(120), and receiver(130). The retransmission decision unit determines one mode of a synchronous retransmission and asynchronous synchronous retransmission as a retransmission mode. The receiver receives an ACK from the receiving terminal, and the transmission unit transmits new data to the receiving terminal. The receiver receives an NAK from the receiving terminal. The transmission unit transmits retransmission data according to a decision from the retransmission decision unit.
Abstract:
A signal transmitting method and a signal receiving method are provided to increase a yield of a random access channel by restricting the access to the random access channel depending on the availability of the random access channel and reduce a data transmission delay by simplifying a bandwidth allocation process. A base station(10) broadcasts a field of a high speed RAC signal as 0 for an available random access channel. A mobile station(20) selects a random access preamble code corresponding to a requested length and MCS(Modulation Coding Scheme) level among random access preamble code set, and chooses one of the random access channels which has a field of a high speed RAC signal as 0. The mobile station transmits the selected preamble code and a random access message to the base station. If the base station is unable to receive the random access preamble code and the random access message, the base station broadcasts as a field of a high speed RAC signal as 0 without a random access response of a random access channel. When the mobile station receives the field of a high speed RAC signal as 0, performs a bandwidth request ranging procedure to transmit data or selects another random access channel to retransmit a random access data.
Abstract:
A method and an apparatus for initial access in a communication system are provided to select modulating and encoding methods and perform resource allocation properly according to the size of a data packet in an initial arbitrary access process, thereby improving efficiency in a use for wireless resources and reducing an access delay time. A method for initial access in a communication system comprises the following steps of: allowing an MS(Mobile Station)(100) to transmit an initial ranging signal to a BS(Base Station)(200) for attempting access to a network initially; allowing the BS to estimate a sub set, to which a code belongs, from the code included in the ranging signal(S120); allowing the BS to check a transmission power level used in the MS and the request bandwidth level of the MS(S130); allowing the BS to compare the transmission power level used in the MS with the receiving power level of the received code and estimate a transmission loss between the MS and the BS(S140); allowing the BS to determine modulating and coding methods used in the MS(S150); allowing the BS to determine a transmission method and uplink resources allocated to the MS and notify the MS of the determined transmission method and the uplink resources through a downlink MAP(Media Access Point)(S160); and allowing the MS to transmit a data packet to the BS by using uplink resources allocated by the determined transmission method(S170).
Abstract:
A method for allocating a terminal to a group in the BS of a communication system and a map generating method are provided to reduce the number of bits consumed in radio resource allocation signaling for plural small packets by the allocation of the group and to be capable of multiple input/output and a hybrid automatic repetition request in uplink. A method for allocating a terminal to a group in the BS(Base Station) of a communication system comprises the following steps of: receiving the channel state information of the terminal(S210); designating the group which the terminal will belong to according to the channel state information(S220); and transmitting a map including first allocation information for the group to the terminal(S240). The first allocation information includes the identifier of the group and the radio resource information of a group burst.
Abstract:
A random access channel operation method in a mobile communication system is provided to enable a base station to dynamically change a transmission type according to a load degree by measuring a load of a random access channel, thereby increasing a usage rate of the random access channel as preventing additional delay. A transmission mode is selected according to a load of a random access channel, and the selected mode is transmitted to a portable terminal(S610). At this time, the load measurement is performed based on the measurement of NI(Noise and Interference). A message having a format corresponding to the selected transmission mode is received from the portable terminal(S620). It is decided whether the received message includes a preamble or data(S640,S650). If data only or both data and preamble is or are included in the message, a response message for data reception is transmitted to the portable terminal(S653,S655,S690).
Abstract:
An uplink synchronization request method in a mobile communication system, a CDMA(Code Division Multiple Access) allocation IE(Information Element) structure in accordance with the method, and a device therefor are provided to enable a PSS(Portable Subscriber Station) to calculate uplink synchronization timing and to synchronize uplink, thereby magnifying resource usage efficiency used for the uplink synchronization. If uplink traffic exists, it is decided whether an uplink synchronization error exists(S820,S830). If so, a timing adjustment value is calculated(S840). A bandwidth request code including the calculated timing adjustment value is transmitted to an RAS(Radio Access Station), so that a bandwidth request is carried out(S850). Before performing the steps 'S820,S830', initial ranging with the RAS is performed, and an initial timing value is stored(S810).
Abstract:
본 발명은 OFDMA 이동통신 시스템에서의 간섭을 제거하는 수신 방법 및 장치에 관한 것이다. 이를 위하여 본 발명은 이동 단말기가 인접 기지국 및 원거리 기지국의 간섭 신호가 포함된 데이터 신호가 실려있는 부반송파를 서비스 기지국으로부터 수신하고, 부반송파 중 주파수 축 또는 시간 축 상에서 인접한 하나 이상의 파일롯 부반송파를 이용하여, 서비스 기지국과 인접 기지국에 대한 채널 응답을 추정한 뒤, 간섭 신호의 제거를 위한 가중치를 계산하고, 계산된 가중치를 이용하여 수신된 부반송파 중 반복되는 동일 데이터 심볼을 갖는 하나 이상의 데이터 부반송파를 합성함으로써, 간섭 신호가 제거된 데이터 심볼을 산출하는 간섭 제거 수신 방법을 제공한다. 본 발명에 의하면, 서비스 기지국 신호에 대한 수신 성능을 향상시킬 수 있어 주파수를 재사용 및 시스템 용량 증대가 가능하며, 핸드오프 상황에서도 서비스 기지국 및 인접 기지국으로부터의 신호를 성공적으로 복조할 수 있어 핸드오프 성공률을 높이고 핸드오프 지연 시간을 감소시킬 수 있다. 간섭 제거, 단일 안테나, 반복 전송, OFDMA
Abstract:
본 발명은 구조적인 시공간 부호 및 그 생성 방법과, 그 시공간 부호를 사용한 다중 안테나 시스템에 관한 것이다. 이 시공간 부호는 하나의 블록구간 동안 송신기의 안테나 개수와 공간 다중화율의 곱에 해당하는 심벌들을 전송하도록 송신기의 안테나 개수에 해당하는 크기의 정방행렬인 부호어 행렬-여기서 부호어 행렬의 행(row)은 송신기의 안테나별로 전송되는 결합된 신호들을 나타내고, 부호어 행렬의 열(column)은 송신기의 안테나 개수에 해당하는 타임슬롯을 나타냄-을 가진다. 이 부호어 행렬은 타임슬롯마다 각 송신 안테나가 전송하도록 할당되는 심벌의 개수는 공간 다중화율에 해당하는 개수이고, 각 송신 안테나에 할당된 심벌들은 서로 다른 결합 계수들에 의해 결합되어 각 송신 안테나에 의해 동시에 전송되며, 각 송신 안테나에는 타임슬롯마다 서로 다른 심벌들이 할당되도록 결정된다. 본 발명에 따르면, 최소의 지연을 가지므로 채널변화에 효과적으로 대처할 수 있고, 타임슬롯별 안테나별로 최소의 데이터 심벌의 조합으로 신호가 생성되므로 신호들 간의 유클리디언 거리가 커서 높은 부호화 이득을 얻을 수 있다. 시공간 부호, STC, time space code, 다중 안테나 시스템, 공간 다중화율
Abstract:
Provided are a packet transmission method for transmitting packets in a forward link of a multibeam satellite communication system and a computer-readable recording medium for recording a program that implements the method. The packet transmission method transmitting packets to mobile stations in a forward link of a multibeam satellite communication system, comprising the steps of: wherein downlink beams of a satellite share an orthogonal spreading code set for transmitting packets to the mobile stations, a) generating downlink beam signals by using an identical structure for the radio frames transmitted through the downlink beams and an identical pseudo-noise (PN) scrambling code for generating downlink beam signals; and b) synchronizing transmission timings of frames, symbols and spread chips on the downlink beam signals.