![]() ; ; Chatzinotas, Symeon ![]() in Proceedings of IEEE Global Communications Conference (2017, December) Fast growth of Internet content and availability of electronic devices such as smart phones and laptops has created an explosive content demand. As one of the 5G technology enablers, caching is a ... [more ▼] Fast growth of Internet content and availability of electronic devices such as smart phones and laptops has created an explosive content demand. As one of the 5G technology enablers, caching is a promising technique to off-load the network backhaul and reduce the content delivery delay. Satellite communications provides immense area coverage and high data rate, hence, it can be used for large-scale content placement in the caches. In this work, we propose using hybrid mono/multi-beam satellite-terrestrial backhaul network for off-line edge caching of cellular base stations in order to reduce the traffic of terrestrial network. The off-line caching approach is comprised of content placement and content delivery phases. The content placement phase is performed based on local and global content popularities assuming that the content popularity follows Zipf-like distribution. In addition, we propose an approach to generate local content popularities based on a reference Zipf-like distribution to keep the correlation of content popularity. Simulation results show that the hybrid satellite-terrestrial architecture considerably reduces the content placement time while sustaining the cache hit ratio quite close to the upper-bound compared to the satellite-only method. [less ▲] Detailed reference viewed: 212 (4 UL)![]() Vu, Thang Xuan ![]() ![]() ![]() in IEEE Wireless Communications Letters (2017) Content caching is an efficient technique to reduce delivery latency and system congestion during peak-traffic time by bringing data closer to end users. In this paper, we investigate energy-efficiency ... [more ▼] Content caching is an efficient technique to reduce delivery latency and system congestion during peak-traffic time by bringing data closer to end users. In this paper, we investigate energy-efficiency performance of cache-assisted content delivery networks with wireless backhaul by taking into account cache capability when designing the signal transmission. We consider multi-layer caching and the performance in cases when both base station (BS) and users are capable of storing content data in their local cache. Specifically, we analyse energy consumption in both backhaul and access links under two uncoded and coded caching strategies. Then two optimization problems are formulated to minimize total energy cost for the two caching strategies while satisfying some given quality of service constraint. We demonstrate via numerical results that the uncoded caching achieves higher energy efficiency than the coded caching in the small user cache size regime. [less ▲] Detailed reference viewed: 122 (5 UL)![]() Lei, Lei ![]() in IEEE International Symposium on Wireless Communication Systems (ISWCS), Bologna, Aug. 2017 (2017, August 31) Detailed reference viewed: 298 (17 UL)![]() Vu, Thang Xuan ![]() ![]() ![]() in Proceedings of IEEE 18th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC) (2017, July) Detailed reference viewed: 165 (19 UL)![]() Vu, Thang Xuan ![]() ![]() in IEEE international Conference on Communications (2017, May) Detailed reference viewed: 121 (3 UL)![]() Vu, Thang Xuan ![]() ![]() ![]() in IEEE International Conference on Communications (2017, May) Detailed reference viewed: 111 (3 UL)![]() Vu, Thang Xuan ![]() ![]() in EURASIP Journal on Advances in Signal Processing (2017) Detailed reference viewed: 171 (7 UL)![]() Vu, Thang Xuan ![]() ![]() ![]() in 2017 IEEE Wireless Communications and Networking Conference (WCNC) (2017) Detailed reference viewed: 121 (4 UL)![]() Vu, Thang Xuan ![]() in IEEE Transactions on Signal Processing (2017), 65(1), 228-241 Future mobile networks are facing with exponential data growth due to the proliferation of diverse mobile equipment and data-hungry applications. Among promising technology candidates to overcome this ... [more ▼] Future mobile networks are facing with exponential data growth due to the proliferation of diverse mobile equipment and data-hungry applications. Among promising technology candidates to overcome this problem, cloud radio access network (CRAN) has received much attention. In this work, we investigate the design of fronthaul in C-RAN uplink by focusing on the compression and optimization in fronthaul uplinks based on the statistics of wireless fading channels. First, we derive the system block error rate (BLER) under Rayleigh fading channels. In particular, upper and lower bounds of the BLER union bound are obtained in closed-form. From these bounds, we gain insight in terms of diversity order and limits of the BLER. Next, we propose adaptive compression schemes to minimize the fronthaul transmission rate subject to a BLER constraint. Furthermore, a fronthaul rate allocation is proposed to minimize the system BLER. It is shown that the uniform rate allocation approaches the optimal scheme as the total fronthauls’ bandwidth increases. Lastly, numerical results are presented to demonstrate the effectiveness of our proposed optimizations. [less ▲] Detailed reference viewed: 123 (14 UL)![]() Vu, Thang Xuan ![]() in IEEE Communications Letters (2016), 20(3), 602-605 Cloud radio access network (C-RAN) is a novel architecture for future mobile networks to sustain the exponential traffic growth thanks to the exploitation of centralized processing. In C-RAN, one data ... [more ▼] Cloud radio access network (C-RAN) is a novel architecture for future mobile networks to sustain the exponential traffic growth thanks to the exploitation of centralized processing. In C-RAN, one data processing center or baseband unit (BBU) communicates with users via distributed remote radio heads (RRHs), which are connected to the BBU via high capacity, low latency fronthaul links. In this letter, we study C-RAN with wireless fronthauls due to their flexibility in deployment and management. First, a tight upper bound of the system block error rate (BLER) is derived in closed-form expression via union bound analysis. Based on the derived bound, adaptive transmission schemes are proposed. Particularly, two practical power optimizations based on the BLER and pair-wise error probability (PEP) are proposed to minimize the consumed energy at the RRHs while satisfying the predefined quality of service (QoS) constraint. The premise of the proposed schemes originates from practical scenarios where most applications tolerate a certain QoS, e.g., a nonzero BLER. The effectiveness of the proposed schemes is demonstrated via intensive simulations. [less ▲] Detailed reference viewed: 112 (2 UL)![]() ; Vu, Thang Xuan ![]() in 2016 IEEE 17th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC) (2016) Detailed reference viewed: 84 (6 UL)![]() Vu, Thang Xuan ![]() in 2016 IEEE International Conference on Communications (ICC) (2016) Detailed reference viewed: 75 (1 UL)![]() Vu, Thang Xuan ![]() in IEEE Signal Processing Letters (2015), 22(9), 1354-1358 Detailed reference viewed: 93 (10 UL)![]() Vu, Thang Xuan ![]() in IEEE Transactions on Wireless Communications (2015), 14(8), 4369-4378 Detailed reference viewed: 82 (3 UL)![]() Vu, Thang Xuan ![]() in 2015 IEEE Global Communications Conference (GLOBECOM) (2015) Detailed reference viewed: 88 (2 UL)![]() Vu, Thang Xuan ![]() in IEEE Transactions on Communications (2015), 63(11), 4565-4575 Cloud radio access network (C-RAN) has recently attracted much attention as a promising architecture for future mobile networks to sustain the exponential growth of data rate. In C-RAN, one data ... [more ▼] Cloud radio access network (C-RAN) has recently attracted much attention as a promising architecture for future mobile networks to sustain the exponential growth of data rate. In C-RAN, one data processing center or baseband unit (BBU) communicates with users via distributed remote radio heads (RRHs), which are connected to the BBU via high capacity, low latency fronthaul links. In this paper, we study the compression on fron- thaul uplinks and propose a joint decompression algorithm at the BBU. The central premise behind the proposed algorithm is to ex- ploit the correlation between RRHs. Our contribution is threefold. First, we propose a joint decompression and detection (JDD) algorithm which jointly performs decompressing and detecting. The JDD algorithm takes into consideration both the fading and compression effect in a single decoding step. Second, block error rate (BLER) of the proposed algorithm is analyzed in closed-form by using pair-wise error probability analysis. Third, based on the analyzed BLER, we propose adaptive compression schemes subject to quality of service (QoS) constraints to minimize the fronthaul transmission rate while satisfying the pre-defined target QoS. As a dual problem, we also propose a scheme to minimize the signal distortion subject to fronthaul rate constraint. Numerical re- sults demonstrate that the proposed adaptive compression schemes can achieve a compression ratio of 300% in experimental setups. [less ▲] Detailed reference viewed: 115 (5 UL)![]() Vu, Thang Xuan ![]() in IEEE Wireless Communications Letters (2014), 3(6), 617-620 Detailed reference viewed: 99 (1 UL)![]() Vu, Thang Xuan ![]() in 2013 IEEE 14th Workshop on Signal Processing Advances in Wireless Communications (SPAWC) (2013, June) Detailed reference viewed: 78 (4 UL)![]() Vu, Thang Xuan ![]() in Abstract book of 2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC) (2013) Detailed reference viewed: 72 (2 UL)![]() Vu, Thang Xuan ![]() in EURASIP Journal on Advances in Signal Processing (2013), 170 Detailed reference viewed: 72 (1 UL) |
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