To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Cellular networks have been undebatably a success story, which resulted in wide proliferation and demand for ubiquitous heterogeneous broadband mobile wireless services. With the exponential increase in high-rate traffic driven by a new generation of wireless devices, data is expected to overwhelm cellular network capacity in the near future. Multi-tier heterogeneous cellular networks (HCNs) have been recently proposed as an efficient and cost-effective approach to provide unprecedented levels of network capacity and coverage. Cellular operators have started integrating small cells as a means to provide dedicated additional capacity either where most data usage generally occurs (i.e., enterprises, households) or where user equipments (UEs) are likely to experience poor data rate performance (i.e., cell edges, subway stations and households). Small cells such as femtocells offer radio coverage through a given wireless technology while a broadband wired link connects them to the backhaul network of a cellular operator. In conventional single-tier networks, the macrocell base stations (MBSs) have to cater to the needs of both outdoor and indoor UEs, which leads to poor indoor coverage and the appearance of dead spots [1–3]. In contrast, in femtocell-aided cellular networks, indoor UEs can enjoy high-quality wireless service from their designated femtocell access points (FAPs) in close proximity and outdoor UEs can experience higher capacity gains due to traffic offload by FAPs through the backhaul. Moreover, FAPs have the economical advantage of being less costly to manufacture and maintain as compared with MBSs.
This comprehensive resource explores state-of-the-art advances in the successful deployment and operation of small cell networks. A broad range of technical challenges, and possible solutions, are addressed, including practical deployment considerations and interference management techniques, all set within the context of the most recent cutting-edge advances. Key aspects covered include 3GPP standardisation, applications of stochastic geometry, PHY techniques, MIMO techniques, handover and radio resource management, including techniques designed to make the best possible use of the available spectrum. Detailed technical information is provided throughout, with a consistent emphasis on real-world applications. Bringing together world-renowned experts from industry and academia, this is an indispensable volume for researchers, engineers and systems designers in the wireless communication industry.
Driven by a new generation of wireless user equipment and the proliferation of bandwidth-intensive applications, user data traffic and the corresponding network load are increasing in an exponential manner. Most of this new data traffic is being generated indoors, which requires increased link budget and coverage extension to provide satisfactory user experience. As a result, current cellular networks are reaching their breaking point and conventional cellular architectures, which are devised to cater to large coverage areas and optimized for homogeneous traffic, are facing unprecedented challenges to meet these user demands.
In this context, there has been an increasing interest to deploy small cellular access points in residential homes, subways, and offices. These network architectures, which may be either operator deployed and/or consumer installed and are comprised of a mix of low-power cells underlying the macrocell network, are commonly referred to as small cell networks. By deploying additional network nodes within the local area range and bringing the network closer to end users, spatial reuse and coverage can be significantly improved, thus allowing future cellular systems to achieve higher data rates, while retaining the seamless connectivity and mobility of cellular networks.
Inspired by the attractive features and potential advantages of small cell networks, their development and deployment are gaining momentum in the wireless industry and research communities during the last few years. It has also attracted the attention of standardization bodies such as the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE)-Advanced (see Chapter 14) and the IEEE 802.16 Wireless Metropolitan Area Networks.
Multiple input multiple output (MIMO) communication has been established both theoretically and practically as a means to increase data rates and improve reliability in wireless networks. While single input single output (SISO) wireless communication techniques rely on time domain or frequency domain processing to precode and decode the transmitted and received data signals, multiple antenna communication provides an extra spatial dimension to improve the wireless link performance in terms of error rate, coverage, and/or spectral efficiency.
As interest in MIMO communication has grown, upcoming cellular standards have embraced using multiple antennas at the base stations (BSs) and the mobile user terminals to increase the data rates and improve the performance of the radio link . Multiple antennas are also being considered in small cell networks (SCNs) and femtocell networks as a means to improve coverage and manage interference [2, 3]. The development of MIMO techniques for two-tier networks needs to take into account the specific topology of the network, characterized by irregularity in terms of deployment, operation mode (closed access vs. open access), channel state information (CSI) availability, and backhaul connectivity. In this chapter, we provide an overview of MIMO communication techniques in two-tier networks. We present the state of the art in terms of MIMO precoding and coordination techniques to manage interference in heterogeneous networks. We illustrate the various gains and the associated challenges from using linear precoding with perfect and imperfect channel state information at the transmitter (CSIT) in femtocell networks and evaluate the potential role that multi-antenna communication is bound to play in two-tier networks.