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A comprehensive study is given of smart antennas for wide-band code-division multiple access (WCDMA). It analyzes, evaluates, and presents methods and ideas for the deployment of smart antennas in WCDMA third-generation wireless systems and for future generations. Three major implementations are evaluated and analyzed in a dynamic system simulator: higher order sectorization (HOS), fixed beams (FBs) with secondary common pilot channel (S-CPICH), and FBs with primary common pilot channel (P-CPICH) as a phase reference. The system modeling integrates antenna and wave propagation modeling to evaluate and design smart antennas in wireless communications. Furthermore, this paper analyzes the impact of angular spread of various antenna configurations, the interaction and impact of radio resource management as power tuning of the common channel, scrambling code (SCO) allocation technique, and soft and softer handover algorithm. Moreover, an SCO allocation strategy and an adaptive load-dependent power-tuning algorithm of the P-CPICH are proposed. Furthermore, a signal-to-(interference plus noise) ratio derivation is given. Extensive simulation studies are carried out to evaluate the capacity gains of HOS and FB. The 12-sector sites yield the best system downlink capacity gain compared to three-sector sites equipped with a single antenna, slightly more than three-sector sites equipped with four FBs each. The six-sector sites equipped with two FBs each reduce the gap between HOS and FB systems to 10%. Index Terms--Angular spread, antenna configuration, fixed beams, higher order sectorization, P-CPICH and S-CPICH as phase reference, pilots tuning, propagation modeling, radio resource management, scrambling code allocation, system performance, wide-band code-division multiple access (WCDMA).

Demands for very high system capacity and end-user data rates of the order of 10 Gb/s can be met in localized environments by Ultra-Dense Networks (UDN), characterized as networks with very short inter-site distances capable of ensuring low interference levels during communications. UDNs are expected to operate in the millimeter-wave band, where wide bandwidth signals needed for such high data rates can be designed, and will rely on high-gain beamforming to mitigate path loss and ensure low interference. The dense deployment of infrastructure nodes will make traditional wire-based backhaul provisioning challenging. Wireless self-backhauling over multiple hops is proposed to enhance flexibility in deployment. A description of the architecture and a concept based on separation of mobility, radio resource coordination among multiple nodes, and data plane handling, as well as on integration with wide-area networks, is introduced. A simulation of a multi-node office environment is used to demonstrate the performance of wireless self-backhauling at various loads. [ABSTRACT FROM PUBLISHER]

METIS is the EU flagship 5G project with the objective of laying the foundation for 5G systems and building consensus prior to standardization. The METIS overall approach toward 5G builds on the evolution of existing technologies complemented by new radio concepts that are designed to meet the new and challenging requirements of use cases today?s radio access networks cannot support. The integration of these new radio concepts, such as massive MIMO, ultra dense networks, moving networks, and device-to-device, ultra reliable, and massive machine communications, will allow 5G to support the expected increase in mobile data volume while broadening the range of application domains that mobile communications can support beyond 2020. In this article, we describe the scenarios identified for the purpose of driving the 5G research direction. Furthermore, we give initial directions for the technology components (e.g., link level components, multinode/multiantenna, multi-RAT, and multi-layer networks and spectrum handling) that will allow the fulfillment of the requirements of the identified 5G scenarios. [ABSTRACT FROM PUBLISHER]

A novel scheme for data retransmission for wireless unicast communication is presented. The scheme is based on a transmitter and receiver structure and bit-level data processing using a combination of channel coding and network coding that allows retransmissions to contain previously incorrectly received information and new information, both destined to the same receiver. Results show that, for the chosen codes, up to 68.75% retransmission throughput gains are achieved, compared to Hybrid Automatic Repeat reQuest (HARQ) with Chase combining. [ABSTRACT FROM PUBLISHER]

We present a new space-time encoder based on packet-level redundancy which can increase the space-time encoder rate beyond unity without compromising diversity gains. A complementary low-complexity decoding algorithm based on maximum ratio combining and successive interference cancelation is further proposed. A major merit of the decoding algorithm is that it allows to adaptively tradeoff between diversity and multiplexing gains based on the estimated channel parameters at the receiver without requiring any channel state information at the transmitter. System level simulation results give insight into the advantages of the proposed scheme when compared to its Alamouti and MIMO multiplexing based on single value decomposition counterparts. [ABSTRACT FROM AUTHOR]

Globally, mobile communications are moving toward broadband communication systems to meet the challenges of significantly increasing data traffic such as that for mobile Internet applications. In order to meet this increasing traffic, the International Telecommunication Union ? Radiocommunication Standardization Sector (ITU-R) initiated in 2000 the process toward the next generation of International Mobile Telecommunications systems, referred to as IMT-Advanced systems. ITU-R Recommendation M.1645 specifies the objectives of the future development of the IMT-Advanced family, among them to reach 100 Mb/s for mobile access and up to 1 Gb/s for nomadic wireless access. The research community was asked to develop concepts and system proposals to meet these requirements. These activities were the basis for the preparation of the ITU World Radiocommunications Conference 2007 to identify additional frequency spectrum for mobile and wireless communications. In 2008 ITU-R issued a Circular Letter calling for candidate radio access technologies (RATs) for IMT-Advanced by taking into account the identified frequency bands. In parallel, international specification and standardization bodies were developing technology proposals. Finally, two main technologies were submitted to ITU-R for approval within the IMT-Advanced framework: one based on Third Generation Partnership Project (3GPP) Long Term Evolution (LTE)-Advanced, and the other one based on IEEE 802.16m. ITU-R decided in October 2010 that both submitted IMT-Advanced system proposals successfully met all of the established criteria for the first release of IMTAdvanced, qualifying them as the first true fourth-generation (4G) systems [ABSTRACT FROM PUBLISHER]