Abstract:
PURPOSE: An apparatus and a method of modulating ranging signals in a broadband wireless access communication system are provided to reduce an initial wireless access time and a hand-over delay time by detecting the ranging signals correctly and rapidly. CONSTITUTION: A subscriber terminal is synchronized with a base station through ranging in order to receive base station information from the base station(2301). The subscriber terminal generates a first code assigned to the corresponding base station by using the base station information(2303). The base station generates a second code for distinguishing subscriber terminals from each other within corresponding cells of the base station(2305). A new ranging code is generated by combining the first code with the second code(2307). The ranging code is mapped onto an assigned sub-carrier and is transmitted to the base station(2309,2311).
Abstract:
PURPOSE: A method and an apparatus for controlling a power of a reverse channel in a mobile communication system are provided to control a transmission power of a reverse CQICH(Channel Quality Indicator CHannel). CONSTITUTION: A sector receives a reverse CQICH and a reverse PICH(PIlot CHannel) transmitted from a terminal(401). The sector measures a reception power as to the reverse CQICH and the reverse PICH, and judges whether the corresponding CQICH is erased by using the reception power of the CQICH(402). The sector judges whether a current time interval is a time interval for transmitting a traffic to pilot control bit(403). If the current time interval is the time interval for transmitting the traffic to pilot control bit, the sector calculates a CQICH erasure rate of the corresponding terminal(404). The sector decides whether a CQICH reverse traffic to pilot ratio is increased or decreased by using the calculated CQICH erasure rate(405). If the CQICH erasure rate, which is greater than a desired CQICH erasure rate, is calculated, a base station punctures and inserts a command for increasing the CQICH reverse traffic to pilot ratio into a transmission position of a predetermined PCB(Power Control Bit), and transmits the PCB(406). If the CQICH erasure rate, which is lower than the desired CQICH erasure rate, is calculated, the base station punctures and inserts a command for decreasing the CQICH reverse traffic to pilot ratio into the transmission position of the predetermined PCB, and transmits the PCB(407).
Abstract:
PURPOSE: A transmit diversity method and apparatus for maximizing the transmit data throughput in an HDR(High Data Rate) system is provided to improve the forward data throughput in an HDR system. CONSTITUTION: A pilot channel, an FAB(Forward Activity Bit) channel, and an RAB(Reverse Activity Bit) channel, common channels for all the mobile stations, among the time division multiplexed channels are transmitted through both antennas at half power(S110). A traffic channel and an RPC(Reverse Power Control) channel, specific mobile station user channels, are transmitted through either of the two antennas according to AS(Antenna Selection) information received from the mobile station(S120).
Abstract:
PURPOSE: A method and an apparatus for transmitting DRC(Data Rate Control) information in a communication system for fast data transmission are provided to transmit DRC information, reversely transmitted to determine the data rate of a downlink in an HDR(High Data Rate) system, only at a necessary point of time for scheduling. CONSTITUTION: An AT(Access Terminal) reads a DRI(DRC Request Indicator) bit transmitted through a downlink MAC(Media Access Control) channel(401) and judges whether the value of the DRI bit is "1"(402). If it is judged that the value of the DRI bit is "1", the AT measures the pilot C/I(Carrier to Interference ratio) of each available sector(403) and determines the largest C/I and the sector(404). Then the AT makes the largest C/I into a DRC symbol(405) and transmits the DRC symbol to an AN(Access Network)(406). Then the AT receives the next slot(407).
Abstract:
PURPOSE: A method for controlling a reverse rate in a mobile communication system supporting a packet data service and a device therefor are provided to properly change transition probabilities used to determine a rate of a reverse data channel, according to the number of terminals within a cell or a reverse load, thereby improving a reverse throughput. CONSTITUTION: A system measures the number of terminals serviced with packet data or a reverse load(200). The system selects transition probability sets relative to the measured number of the terminals or the reverse load among plural transmission probability sets that are predetermined to be identical with the terminals(210). The transition probability sets consist of upper transition probabilities and lower transition probabilities. In order to control a reverse rate by using the selected transmission probability sets, the system transmits indicator information on the selected transition probability sets to the terminals(220).
Abstract:
본 발명은 후보 벡터 검출 방법 및 이를 이용한 송신 심볼 검출 방법에 관한 것이다. 본 발명에 따르면, 공간 다중화 방식을 사용하는 다중 송수신 시스템에서 수신기는 재정렬된 복수의 레이어 중 마지막 행에 위치하는 레이어에 해당하는 후보 벡터들을 선택하고, 그 다음 레이어의 성상점들을 선택된 후보 벡터 별로 차례대로 나열한다. 그리고, 나열된 성상점들 중에서 복수의 임시성상점을 선택하고, 임시성상점들의 누적비용을 산출하여 최소누적비용을 보이는 성상점에 대응하여 후보 벡터를 선택한다. 이후, 후보 벡터로 선택된 성상점 대신 새로운 임시성상점을 선택하고 선택된 임시성삼점의 누적비용과 나머지 임시성상점들의 누적비용을 비교하여 또 다른 후보 벡터를 선택한다. 공간 다중화, MIMO, 다중 송수신 시스템, 후보 벡터, 송신 심볼, 로그우도비
Abstract:
A method and an apparatus for allocating sub channels in a communication system are provided to prevent degradation of performance due to a collision among sub channels by allocating some of the allocated sub channel as a pilot channel. An overall frequency band is divided into m sub channel groups which have respective sub channel group indexes. One of the sub channels includes n selected sub carriers in the respective sub channel groups corresponding to a sub channel group index sequence. When a signal transmitter transmits the same signals at first and second timings, a sub channel allocator(517) allocates the first sub channel by using the first sub channel group index sequence at the first timing. The first sub channel group index sequence is different from a second sub channel group index sequence which is used for allocating second sub channels at the second timing.