Abstract:
A method for managing channels by using receiving performance of a terminal and a wireless communication system thereof are provided to improve PAPR(Peak to Average Power Ratio) performance of an entire system when differently setting a modulation mode and a frequency channel according to a terminal group classified by a performance class determined through Eb/No, RSSI(Received Signal Strength Indicator), RTD(Round Trip Delay). A channel managing method comprises the following steps of: measuring Eb/No and RSSI(Received Signal Strength Indicator) received from a terminal, and reporting the measured Eb/No and RSSI to a base station(301,302); calculating RTD(Round Trip Delay) in the base station(303); and determining a terminal performance class by using the measured Eb/No and the RSSI, and the calculated RTD and then determining a frequency channel and a modulation mode through the determined performance class(304,305).
Abstract:
A sub channel allocation and fixed beam forming method for maximizing transmission efficiency in an orthogonal frequency division multiplexing access(OFDMA) system and an apparatus for using the same are provided to remove an interference signal with minimum costs by allocating a sub channel advantageous to each user device. A sub channel for each user device is determined, on the basis of the channel state of each user device. Beam index for each user device is determined, on the basis of position information and arrival direction information of each user device. An OFDM(Orthogonal Frequency Division Multiplexing) symbol is generated by mapping the symbol corresponding to each user device to the determined sub channel. The generated OFDM symbol is transmitted to wireless space by forming a beam according to the determined beam index.
Abstract:
본 발명은 직교 주파수 분할 다중 접속 기반의 인지 무선 시스템에서 유연한 대역폭을 사용하는 방법, 이를 이용하는 기지국 및 단말에 관한 것으로, 이 기지국은 사용되지 않는 채널 대역들 중에서, 대역폭 해상도- 상기 대역폭 해상도는 방송 채널 대역의 대역폭보다 작은 소정의 대역폭- 의 자연수 배의 대역폭을 가지는 채널 대역을 상기 단말에 할당하는 대역할당부; 및 상기 할당된 채널 대역에 대한 정보를 나타내는 대역 할당 정보를 포함하는 OFDMA 기반 신호를 송신하는 송신부를 포함한다. 본 발명에 따르면 조각 대역 및 조각 대역의 묶음에 해당되는 사용되지 않는 대역을 효과적으로 활용할 수 있으며, 데이터전송률(data rate)을 유연하게 사용할 수 있다. Cognitive radio, WRAN, OFDMA, flexible bandwidth usage, fractional bandwidth, channel bonding, channel aggregation