Scheduling and Capacity Estimation in LTE

• Autorzy: Østerbø O.
• Języki publikacji: EN

Abstrakty

EN

Due to the variation of radio condition in LTE the obtainable bitrate for active users will vary. The two most important factors for the radio conditions are fading and pathloss. By considering analytical analysis of the LTE conditions including both fast fading and shadowing and attenuation due to distance we have developed a model to investigate obtainable bitrates for customers randomly located in a cell. In addition we estimate the total cell throughput/capacity by taking the scheduling into account. The cell throughput is investigated for three types of scheduling algorithms; Max SINR, Round Robin and Proportional Fair where also fairness among users is part of the analysis. In addition models for cell throughput/capacity for a mix of Guaranteed Bit Rate (GBR) and Non-GBR greedy users are derived. Numerical examples show that multi-user gain is large for the Max-SINR algorithm, but also the Proportional Fair algorithm gives relative large gain relative to plain Round Robin. The Max-SINR has the weakness that it is highly unfair when it comes to capacity distribution among users. Further, the model visualize that use of GBR for high rates will cause problems in LTE due to the high demand for radio resources for users with low SINR, at cell edge. Persistent GBR allocation will be a waste of capacity unless for very thin streams like VoIP. For non-persistent GBR allocation the allowed guaranteed rate should be limited.

Słowa kluczowe

EN

LTE; scheduling; capacity estimation; GBR

• Wydawca: Publishing House of Poznan University of Technology
• Czasopismo: Advances in Electronics and Telecommunications
• Rocznik: 2011
• Tom: Vol. 2, no. 3
• Strony: 31--42
• Opis fizyczny: Bibliogr. 6 poz., rys.

Twórcy

autor

Østerbø O.

• Telenor, Corporate Development, Fornebu, Oslo, Norway

Bibliografia

• [1] H. Holma and A. Toskala, LTE for UMTS, OFDMA and SC-FDMA Based Radio Access. Wiley, 2009.
• [2] R.-. 3GPP TSG-RAN1#48, “LTE physical layer framework for performance verification,” 3GPP, St. Louis, MI, USA, Tech. Rep., Feb. 2007.
• [3] H. Kushner and P. Whiting, “Asymptotic Properties of Proportional-Fair Sharing Algorithms,” in Proc. of 2002 Allerton Conference on Communication, Control and Computing, Oct. 2002.
• [4] 3GPP TS 36.213 V9.2.0, “Physical layer procedures, Table 7.2.3-1: 4-bit CQI Table,” 3GPP, Tech. Rep., Jun. 2010.
• [5] M. C, M. Wrulich, J. C. Ikuno, D. Bosanska, and M. Rupp, “Simulating the Long Term Evolution Physical Layer,” in Proc. of 17th European Signal Processing Conference (EUSIPCO 2009), Glasgow, Scotland, Aug. 2009.
• [6] B. Sklar, “Rayleigh Fading Channels in Mobile Digital Communication Systems Part I: Characterization and Part II: Mitigation,” IEEE Commun. Mag., Jul. 1997.