OFDMA 멀티캐스트 시스템에서 신뢰성 있는 멀티미디어 서비스를 보장하기 위한 패킷 및 서브 캐리어 할당 기법

Joint Packet and Sub-carrier Allocation Scheme to Ensure Reliable Multimedia Service in OFDMA Multicast System

  • 곽용수 (연세대학교 전기전자공학부) ;
  • 김영용 (연세대학교 전기전자공학부)
  • Gwak, Yong-Su (Yonsei University, School of Electrical and Electronic Engineering) ;
  • Kim, Yong-Young (Yonsei University, School of Electrical and Electronic Engineering)
  • 발행 : 2009.04.25

초록

우리는 BMPA(balanced multimedia packet allocation) 기법을 제안했다. 이 기법은 OFDMA 멀티캐스트 시스템에서 서브캐리어의 최적 할당 문제를 고려했다. RT(real time) 패킷과 NRT(non-real time) 패킷이 송신 단에 동시에 도달했을 경우, BMPA 기법은 RT 패킷에 NRT 패킷보다 더 큰 가중치를 부여한다. 그리고 각 유저의 패킷 가중치 합에 따라서 서브 캐리어를 할당한다. 이 과정이 패킷 스케듈링과 서브 캐리어 할당 과정을 동시에 수행하게 되고 각 유저는 멀티미디어 패킷을 안정적으로 전송받을 수 있다. 시뮬레이션 결과를 통해 BMPA 기법이 기존의 멀티유저 워터필링 알고리즘에 비해 장기적으로 시스템의 전송 속도를 높이고 RT 패킷의 지연을 크게 줄인다는 것을 증명했다.

We propose BMPA(balanced multimedia packet allocation) scheme. This scheme considers the issue of optimal sub-carrier allocation in OFDMA multicast system. When RT(real time) packets and NRT(non-real time) packets arrive at the same time, BMPA scheme gives higher weight to RT packets than NRT packets and then, it allocates sub-carriers according to the total weight sum of packets in each user. This process acts as both packet scheduler and sub-carrier allocation. Therefore, each user receives multimedia packets with reliability. With simulation results, it shows that BMPA scheme ensures long-term system throughput and, in average RT packet delay, BMPA scheme greatly outperforms multi-user water-filling algorithm.

키워드

참고문헌

  1. M. Ergen, S. Coleri and P. Varaiya, 'QoS aware adaptive resource allocation techniques for fair scheduling in OFDMA based broadband wireless access systems,' IEEE Transactions on Broadcasting, vol. 49, no. 4, Dec. 2003
  2. J. Jang, K.B. Lee, and Y.H. Lee, 'Transmit Power and Bit Allocations for OFDM Systems in a Fading Channel,' Proc. IEEE GLOBECOM 2003, Dec. 2003
  3. S. Pfletschinger, G. Munz, J. Speidel, 'An efficient water-filling algorithm for multiple access OFDM,' IEEE Globecom '02, Taipei, Taiwan, November 2002
  4. S. Kittipiyakul and T. Javidi, 'Subcarrier allocation in OFDMA systems: beyond water- filling,' in Proc. 2004 Asilomar Conference on Signals, Systems, and Computers, Nov. 2004
  5. W. S. Jeon and D. G. Jeong, 'Combined connection admission control and packet transmission scheduling for mobile Internet services,' IEEE Trans. Veh. Technol., in press https://doi.org/10.1109/TVT.2006.878562
  6. S. S. Jeong, D. G. Jeong, and W. S. Jeon, 'Cross-layer Design of Packet Scheduling and Resource Allocation in OFDMA Wireless Multimedia Networks,' IEEE VTC 2006, May. 2006
  7. Ahmed K. F. Khattab and Khaled M. F. Elsayed, 'Opportunistic Scheduling of Delay Sensitive Traffic in OFDMA-based Wireless Multimedia Networks,' in Proc. 2006 International Symposium on a World of Wireless, Mobile and Multimedia Networks, June. 2006
  8. S. Kittipiyakul and T. Javidi, 'A Fresh Look at Optimal Subcarrier Allocation in OFDMA Systems,' IEEE CDC 2004, Dec. 2004 https://doi.org/10.1109/CDC.2004.1428986
  9. A. Khattab, 'Channel-aware scheduling of delay-bounded multimedia traffic in wireless networks beyond 3G,' M.Sc. Thesis, Cairo University, Egypt, 2004