Aspects disclosed herein relate to channel and interference estimations in a coordinated multi-point (CoMP) environment. In the disclosed aspects, an eNB may be equipped to signal an identifier indicating a plurality of resource patterns, each associated with a resource pattern group, and each including a first resource element pattern for channel estimation and a second resource element pattern for interference estimation. The UE may be equipped to receive the signaling and perform channel estimation based at least in part on the first resource element pattern, and interference estimation based at least in part on the second resource pattern generate at least one channel state report based on the channel and interference estimations, and transmit at least one channel state report to an eNB. The eNB may determine one or more resources for use by the UE based on the at least one received channel state report.

Method and apparatus for enabling channel and interference estimations in macro/rrh system

Telecommunications networks are undergoing major changes so as to meet the requirements of the next generation of users and services, which create a need for a general revised architectural approach rather than a series of local and incremental technology updates. This is especially manifest in mobile broadband wireless access, where a major traffic increase is expected, mostly because of video transmission and cloud-based applications. The installation of a high number of very small cells is foreseen as the only practical way to achieve the demands. However, this would create a struggle on the mobile network operators because of the limited backhaul capacity, the increased energy consumption, and the explosion of signalling. In the FP7 project CROWD, Software Defined Networking (SDN) has been identified as a solution to tame extreme density of wireless networks. Following this paradigm, a novel network architecture accounting for MAC control and Mobility Management has been proposed, being the subject of this paper.

An SDN-Based Network Architecture for Extremely Dense Wireless Networks

In this article we present two promising practical use cases for simple multicell cooperation for LTE-Advanced heterogeneous network scenarios with macro and small cells. For co-channel deployment cases, we recommend the use of enhanced interference coordination, or eICIC, to mitigate cross-tier interference and ensure sufficient offload of users from macro to small cells. It is shown how the eICIC benefit is maximized by using a distributed inter-base station control framework for dynamic adjustment of essential parameters. Second, for scenarios where macro and small cells are deployed at different carriers an efficient use of the fragmented spectrum can be achieved by using collaborative inter-site carrier aggregation. In addition to distributed coordination/collaboration between base station nodes, the importance of explicit terminal assistance is highlighted. Comprehensive system-level simulation results illustrate the performance benefits of the presented techniques.

Multicell cooperation for LTE-advanced heterogeneous network scenarios

Heterogeneous network, or HetNet, deployments are one of the key enablers in providing ubiquitous coverage and capacity enhancements for LTE-Advanced networks. They play an important role in achieving high data rate and quality of service requirements defined for next generation wireless networks. In this article we evaluate various cell discovery techniques tailored for energy-efficient detection of small cells deployed in a carrier other than the serving macrocell. The presented schemes are evaluated using extensive system simulations conducted in a 3GPP LTE-Advanced HetNet scenario. Shortcomings of the currently standardized mechanism are analyzed, and advantages of the evaluated schemes are presented. Both the offloading opportunity utilization and savings in UE battery power consumption are analyzed. The results show that using the considered flexible, adaptive, and intelligent schemes for small cell discovery, significant UE power savings can be achieved with small loss in offloading - giving benefits both on system level as well as in user experience.

Energy-efficient inter-frequency small cell discovery techniques for LTE-advanced heterogeneous network deployments

Machine-to-machine communication over long-term evolution advanced (LTE-A) network has emerged as a new communication paradigm to support a variety of applications of Internet of Things. One of the most effective techniques to accommodate a large volume of machine type communication (MTC) devices in LTE-A is clustering where devices (nodes) are grouped into number of clusters and forward their traffics to the base station (e.g., LTE eNodeB) through some special nodes called cluster heads (CHs). In many applications, the CHs change location with time that causes variation in distances between neighboring CHs. When these distances increase, the performance of data transmission may degrade. To address this issue, we propose to employ intermediate non-CH nodes as relays between neighboring CHs. Our solution covers many aspects from relay selection to cooperative formation to meet the user’s QoS requirements. As the number of total relay plays a significant role in cooperative communications, we first design a rateless-coded-incremental-relay selection algorithm based on greedy techniques to guarantee the required data rate with a minimum cost. After that, we develop both source-feedback and non-source-feedback-based fountain coded cooperative communication protocols to facilitate the data transmission between two neighbor CHs. Numerical results are presented to demonstrate the performance of these protocols with different relay selection methods under Rayleigh fading channel. It shows that the proposed source-feedback-based protocol outperforms its non-source-feedbackprotocol counterpart in terms of a variety of metrics.

Fountain Coded Cooperative Communications for LTE-A Connected Heterogeneous M2M Network

LTE-Advanced extends the capabilities originally developed in LTE within the 3GPP. Carrier aggregationis the most significant, albeit complex, improvement provided by LTE-Advanced. Bandwidths from various portions of the spectrum are logically concatenated resulting in a virtual block of a much larger band, enabling increased data throughput. Additionally, enhancements to MIMO antenna techniques in the uplink and downlink further increase the data throughput. Cell coverage is improved by means of relay nodes, which connect to donor eNode-Bs. To cope with the many varieties of cell types and sizes (macro, pico, femto), intercell interference control is enhanced to handle these heterogeneous networks. Operators hope to leverage LTE-Advanced to offer their mobile wireless customers a vastly superior user experience.

Xiaodong Shen

Papers

LTE-advanced: an operator perspective