CAJ | 학술논문

分别在平坦衰落和频率选择性衰落的无线信道模型中建立了基于多用户正交频分复用技术(OFDM)和分布式天线的认知无线电系统中子载波分配模型.该模型不再用"干扰温度"限制认知用户来保护主用户,而是规定主用户在其所有子载波上的吞吐量之和需要高于一定的门限.然后,根据不同信道模型的特点提出了最优子载波分配方案,该方案利用分支定界法和隐枚举法最大化系统的吞吐量.最后,利用Pegging算法提出了效率与公平折中的子载波分配方案.仿真证明,在不同场景中所提出的子载波分配方案与现有方案相比在吞吐量和公平性方面均具有较大的优势.
분별재평탄쇠락화빈솔선택성쇠락적무선신도모형중건립료기우다용호정교빈분복용기술(OFDM)화분포식천선적인지무선전계통중자재파분배모형.해모형불재용"간우온도"한제인지용호래보호주용호,이시규정주용호재기소유자재파상적탄토량지화수요고우일정적문한.연후,근거불동신도모형적특점제출료최우자재파분배방안,해방안이용분지정계법화은매거법최대화계통적탄토량.최후,이용Pegging산법제출료효솔여공평절중적자재파분배방안.방진증명,재불동장경중소제출적자재파분배방안여현유방안상비재탄토량화공평성방면균구유교대적우세.
The subcarrier allocation problem in cognitive radio (CR) networks with multi-user orthogonal frequency-division multiplexing (OFDM) and distributed antenna is analyzed and modeled for the flat fading channel and the frequency selective channel, where the constraint on the secondary user (SU) to protect the primary user (PU) is that the total throughput of each PU must be above the given threshold instead of the "interference temperature". According to the features of different types of channels, the optimal subcarrier allocation schemes are proposed to pursue efficiency (or maximal throughput), using the branch and bound algorithm and the 0-1 implicit enumeration algorithm. Furthermore, considering the tradeoff between efficiency and fairness, the optimal subcarrier allocation schemes with fairness are proposed in different fading channels, using the pegging algorithm. Extensive simulation results illustrate the significant performance improvement of the proposed subcarrier allocation schemes compared with the existing ones in different scenarios.