CO-CHANNEL INTERFERENCE MITIGATION IN HETEROGENEOUS LTE-A NETWORKS (original) (raw)
Related papers
2013
In long term evolution Advanced (LTE-A), concept of heterogeneous network (HetNet) has been introduced. Since, spectrum has become a rare resource these days; another mean is to be looked after to improve the existing wireless technology. One possible way is to improve the network topology so that frequency spectrum can be reused. In heterogeneous network, lower power nodes like Pico/Femto cell are deployed inside Macro cell to increase the system throughput and network coverage. Traditionally, cell selection for user equipment (UE) in LTE is based upon the received downlink power but these Pico/Femto cell have a low power than the Macro cell, meaning that few users can get access from Femto/Pico cells. UE should be close to the Pico/Femto cell to get connected with it. So its solution is; cell selection based upon the uplink path loss can be applied allowing more UE get connected to Pico/Femto cell. On doing that area of the Pico/Femto cell will increase which is called range extension region. Another problem arises when cell extension is applied, is that Macro cell imposes interference towards the Physical channel and signal of the Pico/Femto cell UE in range extension region as both Macro and Pico/Femto cell operate with same set of frequencies. 3rd Generation Partnership Project (3GPP) LTE-A Enhanced Inter-Cell Interference Coordination (eICIC) scheme has proposed Almost Blank Sub-frame (ABS) as a solution towards the above mentioned interference problem by reducing the activity or muting the Macro sub-frame. So that the corresponding Pico/Femto sub-frame can transmit the user information without interference from Macro cell ABS. For the reason of backward compatibility ABS still transmit certain physical channel and signals like CRSs, PCH, PBCH and PSS/SSS. So, interference still remains in these signals and channels. The main focus of thesis is reducing the impact of collision of cell-specific reference signal (CRS) from Macro and Femto cell as CRS is used for channel estimation. We have developed LTE link level system model for Macro and Femto cell in the Matlab simulator. Effect of difference in power of Macro and Femto CRS on UE under different noise power is investigated. It shows, higher the power of Macro, higher is the interference level. As a result Femto channel estimation quality degrades which in-turn degrades system performance. Combined receiver Interference cancelation (IC) methodology is implemented to reduce the impact of interference between macro and Femto CRS collision, which is based upon the reference signal received power (RSRP). System performance is evaluated with bit error rate (BER) and block error rate (BLER) versus Signal to Noise Ratio (SNR) and compared with the single cell system (without interference) and without IC system. Result confirms that IC method system performance is far better than system without IC and as close to system performance of single cell without interference. Furthermore, use of convolutional encoder, offer approximately 7dB coding gain in terms of SNR. Firstly, we would like to thank Tieto Sweden AB, Karlstad for giving us opportunity to work upon this thesis and providing such a great environment at their office. More importantly, thanks to our company supervisors Pechetty V Prasad, Bengt Hallinger and internal supervisor Arild Moldsvor, We are also thankful to Ireddy Chandra, Shilpika kappa and the whole base band team who helped and guide us in our difficult time.
Inter-Cell Interference Management in LTE-A Small-Cell Networks
2013 IEEE 77th Vehicular Technology Conference (VTC Spring), 2013
This paper is concerned with inter-cell interference in co-channel Long-Term Evolution-Advanced (LTE-A) smallcell networks (SCNs). A practical SCNs architecture with smallcell group muting (SCGM) is proposed to mitigate the interference between the hosting macro-cell and small-cells as well as interference between adjacent small-cells. Lower power consumption can also be achieved in the proposed architecture. Our system level simulation results show that the proposed solution outperforms today's default operational methods in terms of both macro-cell average and cell-edge throughput.
POSSIBLE SOLUTIONS FOR INTERFERENCE COORDINATION IN HETNETS OF LTE-A
IAEME PUBLICATION, 2021
In recent advances in cellular communication, the concept of heterogeneous networks has gained significant importance. A heterogeneous network is poised of multiple radio access technologies, architectures, transmission solutions, and base stations of varying transmission power that can interoperate, thus creating a multilayer structure. Management of interferences caused by the macro station to the low power nodes and vice versa is one of the biggest challenges in the deployment of heterogeneous networks. This paper presents a study of the mutual interference between a Macro cell and a Pico cell within LTE-A (Long Term Evolution – Advanced) framework. It is assumed that the Macro cell and the Pico cell share the same frequency channel and only the downlink (DL) performance is studied. In this paper, the possible solutions of enhanced inter-cell interference coordination (eICIC) in terms of throughput and power are analyzed.
Modeling and Mangement of InterCell Interference in Future Generation Wireless Networks
2012
There has been a rapid growth in the data rate carried by cellular services, and this increase along with the emergence of new multimedia applications have motivated the 3rd Generation Partnership (3GPP) Project to launch Long-Term Evolution (LTE) [1]. LTE is the latest standard in the mobile network technology and is designed to meet the ubiquitous demands of next-generation mobile networks. LTE assures significant spectral and energy efficiency gains in both the uplink and downlink with low latency. Multiple access schemes such as Orthogonal Frequency Division Aultiple Access (OFDMA) and Single Carrier Frequency Division Multiple Access (SC-FDMA) which is a modified version of OFDMA have been recently adopted in 3GPP LTE downlink and uplink, respectively [1]. A typical feature of OFDMA is the decomposition of available bandwidth into multiple narrow orthogonal subcarriers. The orthogonality among subcarriers causes minimal intra-cell interference, however, the inter-cell interfere...
Inter-cell Interference Management Technique for Multi-Cell LTE-A Network
International Journal of Electrical and Computer Engineering (IJECE), 2017
In modern cellular system such as LTE Advanced (LTE-A), frequency reuse scheme is targeted to be applied to fulfill the requirement of high capacity broadband access and high spectrum efficiency. But this kind of frequency planning may lead to the worse inter-cell interference (ICI) level experienced especially by a user located at the cell edge. Soft Frequency Reuse (SFR) is considered as an effective way to mitigate inter-cell interference and maintain capacity. We propose a power division SFR, known as multi level SFR technique to minimize ICI in a designed LTE-A network for suburban environment. Service area of LTE-A network was first developed to deploy particular number of eNB by using LTE network planning tools in the frequency of 1800 MHz with the use of SISO (Single Input Single Output) antennas. Coverage dimensioning and propagation consideration determine LTE-A parameters which were used in the simulation. Monte carlo simulation is executed to examine the performance of SFR for LTE-A downlink transmission to address different power ratio and traffic loads problem. Both performance of cell edge users and overall cell performance are evaluated in terms of CINR, BLER, and throughput. Performance with SFR is also compared with the classical frequency reuse one and three.
Adaptive muting ratio in enhanced Inter-Cell Interference Coordination for LTE-A systems
2014 International Wireless Communications and Mobile Computing Conference (IWCMC), 2014
In recent years, we have witnessed a rapid evolution of wireless communication technologies to meet the ever increasing demand of diversified mobile services. It is expected that mobile traffic volume will continue to increase in the following years with a massive diffusion of connected devices and a wide range of quality of service requirements. This represents a challenge for future wireless systems, which shall guarantee high-quality and high-data rate services into limited spectrum. OFDMA femtocells have been pointed out by the industry as a good solution not only to overcome the indoor coverage problem but also to deal with the growth of traffic within macrocells. However, the deployment of a new femtocell layer may have an undesired impact on the performance of the macrocell layer. The resource allocation and the avoidance of electromagnetic interference are some of the more urgent challenges that operators face before femtocells become widely deployed. Following the primary/secondary paradigm, low power nodes shall have cognitive capabilities in order to monitor the network status and optimize their transmission reducing the interference to the primary licensed system. Otherwise, some types of coordination are often used to manage each transmission and to avoid that set of issues. This is possible when both systems are aware of the presence of the other transmission point and a control channel is available to each other. The use of multiple antennas for wireless communication systems has gained overwhelming interest during the last decade-both in academia and industry. Multiple antennas can be utilized in order to accom
Interferences and solutions in long term evolution (LTE) network: A review
Journal of Telecommunication, Electronic and Computer Engineering, 2017
LTE is an enhanced of Universal Mobile Telecommunications Systems (UMTS) network, enriched with new and outstanding features geared towards its network and mobile users. Hence, it can improve poor network coverage and quality of service (QoS). Improper network designed by network operators and random deployments of femtocell behaviour will attract interferences and severely degraded the LTE network. This paper reviewed several interference management techniques to improve LTE network performances based on Third Generation Partnership Project (3GPP) in Rel-8 until Rel-12 from recent studies. This paper covers several interferences i.e. co-channel interference (CCI), cross-tier interference and inter-cell interference (ICI). The techniques reviewed focus on victim users e.g. at cell-edge and indoor areas in heterogeneous networks (HetNets). All techniques were explained and the variables used were reviewed.
Impact Analysis of Enhanced Inter Cell Interference Coordination on Hetnet Topology in Lte-A
2019
This is to certify that the thesis prepared by Mr. Kehali Anteneh entitled "Impact Analysis of enhanced Inter-Cell Interference Coordination On HetNet Topology in LTE-A" and submitted in fulfillment of the requirements for the Degree of Master of Science complies with the regulations of the University and meets the accepted standards with respect to originality and quality.
Interference management in LTE-based HetNets: a practical approach
Transactions on Emerging Telecommunications Technologies, 2014
Interference is a major obstacle in radio communications, especially when opportunistic frequency reuse is an inherent requirement for maximizing spectral efficiency in heterogeneous networks. A typical example is encountered in cellular communications where macro cell-edge users receive interference from small cell transmissions that use the same radio frequency band. Innovating interference management algorithms are employed towards this end, which due to their interdependencies with numerous parameters of the target operating scenario and various low-level implementation aspects, need to be prototyped in real-time signal processing platforms in order to be credibly verified. In this paper, we present the development and experimental validation of a macro/femto cell coexistence scenario in close to reallife conditions. The inclusion of an agile interference management scheme increased the signal processing complexity at the physical layer. This overhead was appropriately addressed by engaging advanced parallel processing techniques, optimizations of the arithmetic operations and intelligent reuse of logic and memory resources in the FPGA-based baseband processing architecture.