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The authors declare that they have no competing interests.
Link adaptation (LA) process is a core feature for the downlink of 3GPP long-term evolution (LTE) and LTE-advanced (LTE-A). Through a channel quality indicator (CQI), the receiver suggests to the base station (BS) an appropriate modulation and coding scheme (MCS) according to the current channel conditions. In order to overcome any non-ideality in this process, the outer loop link adaptation (OLLA) algorithm is used to adaptively modify the mapping from signal-to-noise ratio (SNR) to CQI. OLLA basically modifies the measured SNR by an offset, according to whether data packets are received correctly or not, in order to adjust the average block error rate (aBLER) to a target. Although the OLLA technique has been extensively used, there exists a lack of analysis in the literature about its dynamics and convergence conditions. In this paper, a deep analysis of this algorithm has been carried out in order to cover this gap. From this analysis, we propose a new approach to the OLLA, the enhanced OLLA (eOLLA), which is able to adaptively modify its step size as well as to update its offset according to the reception conditions even if no data packets have been received. Thus, for LTE- and LTE-A-realistic scenarios, simulation results show that the proposed eOLLA outperforms the traditional OLLA, achieving a performance gain of up to a 15 % in terms of throughput.
3GPP TS 36.211, Evolved universal terrestrial radio access (E-UTRA); Physical Channels and Modulation (Release 10), V10.7.0, (Sophia Antipolis Valbonne, France, 2013). http://www.3gpp.org/ftp/Specs/archive/36_series/36.211/36211-a70.zip.
A Sampath, P Sarath Kumar, JM Holtzman, in IEEE Vehicular Technology Conference, vol. 2. On setting reverse link target sir in a cdma system, (1997), pp. 929–9332. doi: 10.1109/VETEC.1997.600465.
P Song, S Jin, in International Conference on Communications and Information Technology (ICCIT). Performance evaluation on dynamic dual layer beamforming transmission in tdd lte system, (2013), pp. 269–274. doi: 10.1109/ICCITechnology.2013.6579562.
KI Pedersen, G Monghal, IZ Kovacs, TE Kolding, A Pokhariyal, F Frederiksen, et al, in IEEE Vehicular Technology Conference (VTC Fall), Baltimore, USA. Frequency domain scheduling for OFDMA with limited and noisy channel feedback, (2007), pp. 1792–1796, doi: 10.1109/VETECF.2007.378.
MG Sarret, D Catania, F Frederiksen, AF Cattoni, G Berardinelli, P Mogensen, in 21th European Wireless Conference, Budapest, Hungary. Dynamic outer loop link adaptation for the 5G centimeter-wave concept, (2015), pp. 1–6.
A Agresti, Categorical Data Analysis (John Wiley and Sons, Hoboken, New Jersey, 1990). MATH
G Gómez, D Morales-Jiménez, JJ Sánchez-Sánchez, JT Entrambasaguas, A next generation wireless simulator based on MIMO-OFDM: LTE case study. EURASIP J. Wirel. Commun. Netw. 2010:, 15–11512 (2010).
3GPP TS 36.212, Evolved universal terrestrial radio access (E-UTRA); Multiplexing and Channel Coding (Release 10), V10.9.0, (Sophia Antipolis Valbonne, France, 2015). http://www.3gpp.org/ftp/Specs/archive/36_series/36.212/36212-a90.zip.
S Banach, Sur les operations dans les ensembles abstraits et leur application aux equations integrales. PhD thesis (University of Lwow, Poland (now Ukraine), 1920).
3GPP TS 36.304, Evolved universal terrestrial radio access (E-UTRA); User Equipment (UE) Procedures in Idle Mode (Release 10), V10.8.0, (Sophia Antipolis Valbonne, France, 2014). http://www.3gpp.org/ftp/Specs/archive/36_series/36.304/36304-a80.zip.
RU Andrzej Cichocki, Neural Networks for Optimization and Signal Processing (Wiley, Chichester, 1993). MATH
A El-Koka, K-H Cha, D-K Kang, in International Conference on Advanced Communication Technology (ICACT), PyeongChang, South Korea. Regularization Parameter Tuning Optimization Approach in Logistic Regression, (2013), pp. 13–18.
H Schulzrinne, S Casner, R Frederick, V Jacobson, RTP: a Transport Protocol for Real-time Applications, IETF RFC 3550 (2013). https://www.ietf.org/rfc/rfc3550.txt.
IM Delgado-Luque, F Blanquez-Casado, MG Fuertes, G Gomez, MC Aguayo-Torres, JT Entrambasaguas, et al, in European Signal Processing Conference (EUSIPCO), Bucharest, Romania. Evaluation of latency-aware scheduling techniques for M2M traffic over LTE, (2012), pp. 989–993.
3GPP TS 36.213, Evolved universal terrestrial radio access (E-UTRA); Physical Layer Procedures (Release 10), V10.13.0, (Sophia Antipolis Valbonne, France, 2015). http://www.3gpp.org/ftp/Specs/archive/36_series/36.213/36213-ad0.zip.
D Drajic, S Krco, I Tomic, P Svoboda, M Popovic, N Nikaein, N Zeljkovic, in Conference on Wireless On-demand Network Systems and Services (WONS). Traffic generation application for simulating online games and m2m applications via wireless networks, (2012), pp. 167–174, doi: 10.1109/WONS.2012.6152224.
- eOLLA: an enhanced outer loop link adaptation for cellular networks
Maria del Carmen Aguayo-Torres
Jose Tomas Entrambasaguas
- Springer International Publishing
EURASIP Journal on Wireless Communications and Networking
Elektronische ISSN: 1687-1499
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