Synchronization aspects in LTE small cells

Bladsjo, D.; Hogan, Marie C.; Ruffini, Stefano

doi:10.1109/mcom.2013.6588653

Cited by 74 publications

(49 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Substituting (16), (17), (18), and (20) into (15) shows that for M large enough the probability of decoding error is upper bounded by ε for every message m. By (14) and (19), The power required by this scheme is…”

Section: Hencementioning

confidence: 99%

Energy-efficient communication in the presence of synchronization errors

Huang

Niesen²,

Gupta³

2013

2013 IEEE International Symposium on Information Theory

View full text Add to dashboard Cite

Communication systems are traditionally designed to have tight transmitter-receiver synchronization. This requirement has negligible overhead in the high-SNR regime. However, in many applications, such as wireless sensor networks, communication needs to happen primarily in the energy-efficient regime of low SNR, where requiring tight synchronization can be highly suboptimal.In this paper, we model the noisy channel with synchronization errors as a duplication/deletion/substitution channel. For this channel, we propose a new communication scheme that requires only loose transmitter-receiver synchronization. We show that the proposed scheme is asymptotically optimal for the Gaussian channel with synchronization errors in terms of energy efficiency as measured by the rate per unit energy. In the process, we also establish that the lack of synchronization causes negligible loss in energy efficiency. We further show that, for a general discrete memoryless channel with synchronization errors and a general input cost function admitting a zero-cost symbol, the rate per unit cost achieved by the proposed scheme is within a factor two of the informationtheoretic optimum.I. INTRODUCTION Traditionally, data transmission in a communication system is based on tight synchronization between the transmitter and the receiver. This tight synchronization is usually achieved through either of two strategies. In the first strategy, synchronization is achieved through periodic transmission of pilot signals, followed by transmission of information over the synchronized channel (see, e.g., [1, Chapter 6.3]). In the second strategy, data bits are differentially encoded and then modulated (e.g., differential pulse-positionmodulation) [1, Chapter 4.3.2], which implicitly achieves tight synchronization.The above strategies work well at high signal-to-noise ratios (SNRs) as the energy overhead of achieving tight synchronization is negligible compared to that of data transmission. However, in many applications, such as wireless sensor networks, space communication, or in general any communication system requiring high energy efficiency, communication by necessity has to primarily take place in the low-SNR regime (due to the concavity of the power-rate function). In such scenarios, the energy overhead to achieve tight synchronization becomes significant and can render the aforementioned strategies highly suboptimal in terms of energy efficiency. In fact, requiring tight transmitter-receiver synchronization can have arbitrarily large loss in performance in terms of energy efficiency (see Example 3 in Section III).To mitigate this, in this paper, we develop and analyze a framework to perform data transmission while only requiring loose synchronization between the transmitter and the receiver. To focus on the energyefficiency aspect, we choose the rate per unit cost (with energy being a prime example of the cost) as our performance metric. We model synchronization errors through channel duplications/deletions-an approach introduced in [2]...

show abstract

Section: Hencementioning

confidence: 99%

Energy-efficient communication in the presence of synchronization errors

Huang

Niesen²,

Gupta³

2013

2013 IEEE International Symposium on Information Theory

View full text Add to dashboard Cite

show abstract

“…There exist three fundamental types of synchronization, namely, based on the time, frequency, and phase [5], [6]. Fig.…”

Section: A Time Frequency and Phase Synchronizationmentioning

confidence: 99%

“…We observe that microsecond to nanosecond accuracy is required. It is worth noting that depending on the access radio, different types of synchronization are required [5]. In particular, when the access radio is based on LTE time-division duplex (TDD), where the upstream and downstream can use the same frequency,time, phase and frequency synchronization must be supported.…”

Section: A Mobile Cellular Networkmentioning

confidence: 99%

See 1 more Smart Citation

A Survey of Clock Synchronization Over Packet-Switched Networks

Lévesque

Tipper

2016

IEEE Commun. Surv. Tutorials

114

View full text Add to dashboard Cite

Abstract-Clock synchronization is a prerequisite for the realization of emerging applications in various domains such as industrial automation and the intelligent power grid. This paper surveys the standardized protocols and technologies for providing synchronization of devices connected by packet-switched networks. A review of synchronization impairments and the stateof-the-art mechanisms to improve the synchronization accuracy is then presented. Providing microsecond to sub-microsecond synchronization accuracy under the presence of asymmetric delays in a cost-effective manner is a challenging problem, and still an open issue in many application scenarios. Further, security is of significant importance for systems where timing is critical. The security threats and solutions to protect exchanged synchronization messages are also discussed.

show abstract

“…In this case, achieving frequency and time synchronisation may require the support of backhaul based techniques, which rely on a well performing backhaul solution. The development of new synchronisation solutions such as local deployment of a synchronisation server, over-the-air synchronisation techniques or hybrid solutions can ease the requirements on the backhaul for synchronisation purposes [11].…”

Section: Synchronisationmentioning

confidence: 99%

Small cell backhaul: challenges and prospective solutions

Jafari

López-Pérez²,

Song

et al. 2015

J Wireless Com Network

View full text Add to dashboard Cite

Operators are currently considering the deployment of small cells to complement their macrocellular networks and in crease their coverage and capacity. However, in order to roll-out a large number of small cells and allow anytime, anywhere wireless broadband connectivity through wireless technologies, operators must still face the challenge of backhauling the traffic from the small cells to the core network in a cost-effective manner. In this paper, backhaul challenges for small cell base stations (BSs) are discussed, and potential wired and wireless solutions together with their benefits and drawbacks are presented. The use of large scale antennas systems and free-space optics is also discussed. Moreover, a wireless backhaul planning tool targeted at finding the most cost-effective backhaul solution using a mixture of wireless technologies is presented. Simulation results confirm that the optimum backhaul solution is a combination of various options, which can overcome inherent scenario constraints while providing a cost-effective performance.

show abstract

Synchronization aspects in LTE small cells

Cited by 74 publications

References 1 publication

Energy-efficient communication in the presence of synchronization errors

Energy-efficient communication in the presence of synchronization errors

A Survey of Clock Synchronization Over Packet-Switched Networks

Small cell backhaul: challenges and prospective solutions

Contact Info

Product

Resources

About