Network Coding in Wireless Communications

A Survey of Radio Resource Management for Spectrum Aggregation in LTE-Advanced

“…The Proportional Fair (PF) scheme is also selected as benchmark in many works such as [4], [27], [36] due to its simplicity and good performance. Since PF is aware of the channel condition for each user, it can exploit the multi-user diversity.…”

“…By jointly scheduling CCs and RBs, MSUL exploits each CC more efficiently than Cross-CC PF. [40], [43], [44], [45] -is used as the reference scheme -simple But with no consideration of different channel characteristics and CA capability Proportional Fair (PF) [4], [27], [36] -is utilized as the basic scheme to be extended in the literature -supports tradeoff between the system throughput and fairness -But has no consideration of different CA capability of terminals and does not exhibit good delay performance To improve fairness between UEs of different channel conditions User grouping PF (UG-PF) [52] -allows for user grouping based on the number of CCs which the users can be scheduled on from their locations -introduces a weighting factor so that the user group in cell-edge can have the advantage to access RBs in the CCs of lower frequencies -How to attain a good trade-off between fairness and throughput remains a challenge To improve fairness between UEs of different CA capability Cross-CC PF [27], [36] -by taking the past user throughput information over all aggregated CCs, makes the scheduling metric of CA-capable UEs smaller -achieves better fairness and coverage performance with no degradation in average cell throughput -results in optimal CC assignment once the CC assignment is determined -But the need for exchange of the user past throughput over each CC, remains an issue To improve fairness between UEs of different channels & CA capability…”

“…1. Specifically, the amount of contiguous transmission bandwidth for an operator in a certain geographical area is limited while the extent of available spectrum resources differs depending on the country, with most of the spectrum spread out over different frequency bands and with different bandwidths [4]. In order to meet both the requirement on transmission bandwidth and the utilization of IMT bands, all IMT-Advanced candidate technologies are expected to support spectrum aggregation, within either contiguous or discontinuous spectrum bands [5].…”

Millimeter wave MPA using Metamaterial-substrate Antenna array for Gain Enhancement

“…In the current scenario where the internet is the medium that helps millions to continue their work online, billions to continue their education and a lot of people to connect with each other, Fourth generation(4G) services helped us a lot.But with increasing requirement in the field of science and technology Fifth generation(5G) can perform the work more easily when compared to other generations.There are two sets of frequency bands for 5G networks.From 450 MHz to 6 GHz is the sub-6 GHz region and the Millimeter wave(mm wave) spectrum ranges between 30 and 300 GHz. For 4G and prior generations,we have used radio waves for transmission which have a low bandwidth and are widely utilised by mobile operators, resulting in slower service and more failed connections [1]. So, having the future in mind, we'll need a medium that can handle a lot of data.…”