Abstract: A method and device for determining available spectrums is disclosed in embodiments of the present invention. By applying the technical solution of the embodiments of the present invention, with consideration on the bi-directionality of the interference between wireless communication systems, when introduction of the cognitive system is required, the corresponding frequency will be determined as an available frequency only in the case the incumbent system and the cognitive system can be simultaneously guaranteed to meet the corresponding coexistence criterion among the corresponding frequency and adjacent frequencies thereof, thus ensuring that the determined available frequency band guarantees that the normal operation of the incumbent system is not interfered by the cognitive system while ensuring that the newly-introduced cognitive system can also operate normally without interference of the incumbent system, thereby improving the communication quality of the wireless communication systems.

Abstract: A method and device for determining available spectrums is disclosed in embodiments of the present invention. By applying the technical solution of the embodiments of the present invention, with consideration on the bi-directionality of the interference between wireless communication systems, when introduction of the cognitive system is required, the corresponding frequency will be determined as an available frequency only in the case the incumbent system and the cognitive system can be simultaneously guaranteed to meet the corresponding coexistence criterion among the corresponding frequency and adjacent frequencies thereof, thus ensuring that the determined available frequency band guarantees that the normal operation of the incumbent system is not interfered by the cognitive system while ensuring that the newly-introduced cognitive system can also operate normally without interference of the incumbent system, thereby improving the communication quality of the wireless communication systems.

Abstract: A method and device for multi-user detecting of an OFDM transmission signal are provided. The method includes: combining received signals, at corresponding time-frequency symbol positions in all of multiple repeated Block Units in relation to the same data symbol, into a received data sequence; determining a combined repeated channel response sequence array corresponding to the received data sequence; and detecting the received data sequence using the combined repeated channel response sequence array to obtain data symbols of multiple users. The technical solution can effectively restrain the multi-address interference and the interference between symbols during OFDM transmitting signal and improve the system performance greatly.

Abstract: Multi-users detecting method and device of OFDM transmission signal include that: a received data sequence is composed of the received signal which is in the position of the time and frequency symbol corresponding to the same data symbol in multi-repeating blocks; the composed repeating channel response sequence array which is corresponding to the received data sequence is determined; the received data sequence is detected to acquire the data symbol information of multi-users by using the composed repeating channel response sequence array. The technical solution can effectively restrain the multi-address interference and the interference between symbols during OFDM transmitting signal and improve the system performance greatly.