Carrier Aggregation in 5g Using Millimeter Range Communication

The advancement in technology and smart gadgets have led to the demand for more data and higher data rates. Despite efficient use of spectrum, it is not able to achieve the data rate of 1 Gbps as required by Long Term Evolution Advanced (LTE-A). To achieve such a high data rate, this requires a higher transmission bandwidth which cannot be achieved by a single carrier. So, a new technique is introduced called carrier aggregation to aggregate two or more component carriers to achieve higher bandwidth. The carriers that are to be aggregated can be from continuous spectrum and can also be from different bands which result in three types of carrier aggregation, i.e., intra-band contiguous, intra-band noncontiguous, and inter-band carrier aggregation. The most important feature to move from LTE to LTE-A is carrier aggregation and the main advantage of this is that it is backward compatible. As per 3GPP release it is given that up to five component carriers can be aggregated to achieve a bandwidth of 100 MHz. Thus, in this paper the carrier aggregation up to three-component carriers by taking different number of downlink resource block for each aggregated carrier and comparative study of increment in the bandwidth will be carried out and the simulation results the enhancement of bandwidth using carrier aggregation.

The extension of long term evolution (LTE) networks in unlicensed spectrum areas under the licensed assisted access concept aims at achieving higher transmission rates via the aggregation of the aforementioned bands along with the licensed ones within the 3G Partnership Project framework. A prospect carrier aggregation (CA) scheme should handle efficiently the coexistence of the LTE systems that compete for the same unlicensed spectrum areas along with their incumbent users (i.e., Wi-Fi). In this paper, a novel CA scheme is proposed for licensed/unlicensed MIMO LTE systems that allocates optimally the resources (power and resource blocks) of an evolved Node B to user equipments. Furthermore, the proposed approach handles the coexistence matters within the unlicensed bands with an efficient decentralized way. The new scheme involves the solution to a mixed integer nonlinear programming problem and thus, an optimal low complexity method is proposed based on the Lagrange dual decomposition. Furthermore, the proposed technique is extended to the imperfect channel state information (CSI) case. To that end, a novel listen-before-talk scheme is developed via which the required unlicensed bands CSI are estimated in a blind manner. The performance of all of the proposed techniques is verified via indicative simulations.

In LTE-Advanced, carrier aggregation (CA) is a key enabling technique to increase the peak data rates of users and enhance the mobility management in heterogeneous networks (HetNets) using dual connectivity solutions. Several CA schemes have been proposed with a maximum of five LTE Release 8 component carriers (CCs) where the NxSC-FDMA has been chosen as the bandwidth extension scheme for the uplink. This enables the extension of the bandwidth allocated to a user up to 100 MHz while maintaining backward compatibility with LTE release 8 legacy users. However, CA leads to a severe increase in the peak-to-average-power ratio (PAPR) of the aggregated time domain NxSC-FDMA signal at the user equipment (UE). This is an important issue as it affects the power amplifier (PA) efficiency and hence the coverage of transmissions. In this paper, we propose a low- complexity post-IFFT technique to reduce the PAPR of carrier aggregated NxSC-FDMA signals in the uplink of LTE-Advanced. Several case studies of CA were analyzed by using the proposed technique. Simulation results show that the PAPR improvement is 2.5 dB for the case of 2 CCs at only about 4% of the complexity required by the partial selective mapping (PSLM) technique to achieve the same PAPR reduction.

Carrier aggregation (CA) is a technology first introduced in LTE-Advanced (LTE-A) to increase the peak data rate of 4G networks (for example, the maximum available speed) [1]. The mobile network operator can increase the total available bandwidth for a single user by aggregating multiple channels together, thereby increasing the user data rate as well as the spectrum utilization efficiency and resource allocation flexibility of the entire network. Before LTE-A, mobile network operators could allocate the spectral resource only to a particular user within a single designated frequency band, limiting the maximum channel capacity. The realization of CA allows network operators to create larger channels from nonadjacent spectrum blocks. For example, operators can use a 10-MHz carrier from the 2,100-MHz band and combine it with another 5-MHz carrier from the 700-MHz band to create a 15-MHz LTE channel. The LTE-A standard specifies that each of the component carriers (CCs) of the communication signal is limited to 20 MHz of bandwidth. Aggregation of up to five CCs allows a maximum of 100 MHz of total signal bandwidth, as depicted in Figure 1. This leads to a fivefold increase in channel capacity and data speed [2]. It is projected that CA technology will continue to be widely and intensively used in future-generation communications, such as 5G.

Currently, cellular technology is advancing into the 5G era, which can support data speeds up to 10 Gbps on the uplink side and 20 Gbps on the downlink side. This study aims to plan a 5G NR network by implementing the inter-band carrier aggregation (CA) method. CA is one of the techniques used to achieve high data speeds and to combine two or more radio frequency bands. The primary cell uses band n40 at 2300 MHz with a 40 MHz bandwidth, while the secondary cell uses band n78 at 3500 MHz with a 100 MHz bandwidth. The area that we used for this network design is Agung Podomoro Land (APL) Tower Central Park area in West Jakarta. The propagation model used Urban Macro. Testing process is carried out by comparing the results between using CA and not using CA on the SSRSRP, SS-SINR, and data rate parameters. Simulation results show an average increase in each parameter after the inter-band carrier aggregation method is applied. The SS-RSRP parameter increased by 0.05% with a value of -82.02dBm, the SS-SINR parameter increased by 0.77% with a value of 15.71dB, and the data rate parameter significantly increased by 241.33% with a value of 803.66 Mbps. This proves that implementing the carrier aggregation method can improve the quality and capacity of the network, particularly the data rate, by maximizing the use of the bandwidth and resource block produced by the combination of component carriers.

Long Term Evolution (LTE) Networks are being planned to be upgraded to LTE Advanced along with increasing availability of Release 10 User Equipment (UEs) and Spectrum Availability for Carrier Aggregation. LTE Advanced brings a major step increase in Down Link and Uplink Throughputs and related spectral efficiencies. This paper explains the evolution of Frequency Division Duplex (FDD) throughputs for different Channel Bandwidths. The maximum theoretical physical layer throughputs and expected actual application layer throughputs after removing the necessary overheads by different broadcast, signaling, synchronization & random access channels have been explained with an impact analysis thereof. Throughput gains for upcoming LTE Advanced deployments have been computed for Frame Structure Type 1 (FDD) for Channel Bandwidth of 1.4 MHz, 3MHz, 5 MHz, 10 MHz, 15 MHz and 20 MHz along with Carrier Aggregation of 2 & 5 Component Carriers. Impact of increasing Signaling Channels, retransmissions & code rate on throughputs has been explained so that the computations can be extended to any deployment scenario.

Long Term Evolution-Advanced (LTE-A) is an emerging mobile cellular system envisaged to provide better quality of multimedia applications. Packet scheduling becomes paramount as the LTE-A delivers multimedia applications using packet switching technology. Given that LTE-A is a new technology, its ability to satisfy the Quality of Service (QoS) requirements of multimedia applications demands further performance study. At present, a number of LTE-A simulators are available. However, these simulators in general are too specific in nature or their source codes are not publicly accessible for the research communities. As such, this study presents a novel simulation tool to assist the research communities to study the downlink LTE-A and further optimize packet scheduling performance. This simulation tool accurately models the downlink LTE-A taking user mobility, carrier aggregation, packet scheduling and other aspects that are relevant to the research communities into consideration. The efficacy of the simulation tool is validated through performance study of a number of well-known packet scheduling algorithms.

Carrier Aggregation is an important feature in Long Term Evolution Advanced (LTE-A). It allows operators to provide larger operational bandwidths without the need of having a contiguous, large piece of spectrum. However, an increased bandwidth also needs a larger channel sounding to obtain channel state information (CSI), required for frequency domain scheduling and link adaptation. This constitutes a serious challenge for the uplink since wideband sounding reference signals cannot be transmitted by cell edge (power limited) users and hopped sounding requires a long time to sweep the entire transmission band, thus leading to outdated and less reliable CSI. Also, average interference and its variation in time can seriously jeopardize the CSI at the eNodeB. In this paper, we present an integration of inter cell interference coordination with CSI reporting by reducing the interference variability through controlled allocations. Results show that the entire CSI accuracy can be improved and so does the overall cell performance.

In order to achieve up to 1 Gbit/s peak data rate in the future IMT-Advanced mobile systems, carrier aggregation (CA) technique is introduced by the 3GPP to support higher data rate transmissions over wide frequency bandwidths (up to 100 MHz) in the LTE-Advanced (LTE-A) standards. This technical envisagement puts forward the new challenge in resource allocation. In this paper, we investigates the component carrier (CC) allocation in LTE-A system. We first separate the resource allocation into CC-, resource block (RB)- and power-allocation. Then, an optimization problem that maximizes system sum capacity with proportional fairness(PF) guarantee is formulated. To simplify the optimization problem, we present an approximate RB allocation approach and two alternative objective functions. A greedy algorithm for CC allocation (GACCA) with low computational complexity is presented to solve the simplified optimization problem. To further improve the quality of solution, we introduce cross entropy method into GACCA. Numerical simulations verify the efficiency of the proposed algorithm.

LTE-Advanced (LTE-A) base station with carrier aggregation (CA) function can meet the larger capacity demand and improve the spectrum efficiency. To fulfill such function, the wide operational bandwidth and high isolation carrier-aggregated switch module is proposed to combine two RF signals, namely, component carriers (CCs) in this work. There are many CA scenarios defined in 3GPP TS 36.104, examples of two 20 MHz LTE-A Release-10 CCs at Band 40 and Band 1+Band 5 are used to verify the feasibility of the proposed module in both the intra-band and inter-band CA.

Carrier aggregation is one of the most distinct features of 4G systems including LTE-A (Long Term Evolution Advanced), which is being standardized in 3GPP as part of LTE Release 10. The closed-loop concept with codebook based precoding MIMO (multiple-input multiple-output) and transmission mode selection, termed as RI (rank indicator) selection, have been deployed in LTE-A systems to provide high system performance required by 4G systems. This article focuses on the study of adaptive transmission mode selection in LTE-A carrier aggregation scenarios. We propose an adaptive transmission mode selection scheme using average channel capacity and BER to maximize the average spectral efficiency (ASE) with a given target bit error ratio (BER). Numerical results demonstrate improvement over each fixed modern terms of average spectral efficiency.

Carrier aggregation (CA) is a good solution for third-generation (3G) Long Term Evolution-Advanced (LTE-A) systems to fulfil the system bandwidth (BW) extension requirements and also ensure the backwards compatibility towards 3G LTE. In this paper, we compare the quality of service (QoS) performances of two different multi-user scheduling schemes in CA based LTE-A systems, i.e. separated random user scheduling (SRUS) and joint user scheduling (JUS). The former is simpler but less efficient while the latter is optimal but with higher signalling overhead. Moreover, only one single component carrier (CC) is needed to access for user equipment (UE) in the case of SRUS while all the CCs have to be connected in the case of JUS. Simulation results show that the SRUS scheme is feasible and only little performance loss in continuous and heavy traffic load scenarios with full or Poisson-based finite buffer traffic input.

Carrier Aggregation (CA) is one of the promising features to support the much wider bandwidth for packet transmissions in Long Term Evolution-Advanced (LTE-A) systems. To the best of our knowledge, works regarding the packet scheduling algorithm in LTE-A systems with the CA mechanism have not thoroughly been investigated yet till now. In this paper, we therefore aim to design an efficient packet scheduling algorithm based on the proportional fair criterion in such environment. We focus on downlink transmissions supporting both Real-Time (RT) and non-RT traffics simultaneously. Simulation results show that performance measures in terms of the system throughput, the mean delay, and the fairness are much better than those of a system in which component carriers are not aggregated but used independently.

Carrier Aggregation (CA), which is a method that aggregates multiple Component Carriers (CCs) of the same or different frequency bands, is one of the Long Term Evolution-Advanced (LTE-Advanced) key features. It allows the LTE-Advanced to support wider transmission bandwidth. Another important requirement is that the system needs to support a mixture of LTE-Advanced and the legacy Long Term Evolution (LTE) users simultaneously. The LTE-Advanced users can transmit packets on all of the available CCs whereas the LTE users are limited to transmit packets on a single CC. At the early stage of migration, there will be many LTE users in the LTE-Advanced system. Therefore, CC selection algorithm that is responsible to assign a CC to each newly-arrived legacy LTE users is becoming of paramount importance in the LTE-Advanced system. The existing CC selection algorithms can slightly provide good mobile cellular performance in terms of maximizing the throughput and balancing the load. To further improve the LTE-Advanced performance, this paper proposes a novel CC selection algorithm that takes the channel quality and traffic load in each CC into consideration. It was shown via simulation that the proposed algorithm can significantly improve the downlink LTE-Advanced performance as compared to the conventional CC selection algorithms.

As the perpetually increasing demands of users for high speed, higher data rates over wide bandwidths, lower system latencies in mobile communications, LTE/LTE-Advanced as a 4th Generation of Wireless networks infrastructures widely deployed to provide better support for these requirements. Carrier Ag-gregation(CA) is an important technology for LTE-A providing enhancements to peak data rates, both uplink and downlink, allowing the User Equipment(UE) to receive data on more than one LTE carrier. This increased complexity is expected to affect the UE current consumption. As LTE is restricted with packet-switched services only, the 3G native circuit-switched (CS) voice mechanisms are used in LTE to support voice calls and SMS. For this purpose, the network operator may consider Circuit-switched fallback(CSFB) or IP-Multimedia Subsystems(IMS) as alternatives, for concerned voice quality, call continuity and reliable SMS delivery in deployed LTE networks. In this paper, the performance of UE under CA(10+10 MHz) is analyzed for maximizing data throughput and also describes how the CA affects UE current consumption measurements with different traffic profiles. As a part of Voice over LTE(VoLTE), this paper evaluates the performance of UE under CSFB with its effect on peak data rates and reliability on IMS for deploying voice and SMS services.