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Kaleem, Zeeshan,Li, Yunpeng,Chang, KyungHi IET 2016 IET COMMUNICATIONS Vol.10 No.15
<P>A device-to-device (D2D) discovery scheme is key enabler for proximity-based services in third generation partnership project long-term evolution-advanced systems for public safety (PS) and general LTE scenarios. The deployment of D2D networks results in severe co-channel interference between conventional cellular users and D2D users, and faces proximity interference management challenges because of the co-existence of multiple D2D users. We propose a time and energy-efficient contention-resolving device discovery resource allocation (TEECR-DDRA) scheme that has the capability to enhance the success ratio for discovery of D2D users by reducing collisions among users. Moreover, the proposed TEECR-DDRA scheme has the ability to prioritise PS users to meet their QoS and latency requirements. Furthermore, multi-channel slotted ALOHA with energy sensing can be used to increase the probability of successful discovery of non-PS users. This ability helps to reduce the discovery time of PS users under disaster scenarios, and also reduces the energy consumption of non-PS users by minimising the number of beacon retransmissions. System-level simulations show that the proposed TEECR-DDRA scheme performs remarkably well under D2D network. Compared with the conventional random access scheme, the proposed scheme almost doubles the discovery range and significantly improves the success ratio for discovery of D2D users.</P>
Zeeshan Kaleem,KyungHi Chang 한국통신학회 2012 한국통신학회 학술대회논문집 Vol.2012 No.6
The cloud radio access network (C-RAN) architecture has made possible to use the concept of clusters by combining hundred’ s of base stations by using remote radio heads (RRH), and thus enable us to use the properties of base station cooperative transmission technique, i.e., CoMP. In this paper, we proposed a procedure related to DL/UL CoMP which has fully exploited the cloud architecture and CoMP techniques to mitigate the inter cell interference (ICI), and proposed the method of selecting the proper CoMP technique which not only maximizes the throughput performance for the cell edge users but also keeps in front the throughput of other users in the cooperating set.
Special issue on amateur drone and UAV communications and networks
Jamalipour, Abbas,Kaleem, Zeeshan,Lorenz, Pascal,Choi, Wan Editorial Department of Journal of Communications 2018 Journal of communications and networks Vol.20 No.5
<P>The development of the mini-drones, formally called unmanned air vehicles (UAVs) have captured the attention of hobbyists and the investors due to their enormous applications. Drones have endless commercial applications as well due to the irrelatively small size and ability to fly without an on-board pilot such as in agriculture, photography, surveillance, and numerous public services. The use of drones for achieving high speed wireless communication is one of the most significant applications for next generation communication system (5G). Indeed, drone-based communication network offers encouraging solution to provide wireless connectivity for devices without infrastructure coverage due to e.g., severe shadowing by urban or mountainous terrain, or damage to the communication infrastructure caused by natural disasters.</P>
Block Error Rate and UE Throughput Performance Evaluation using LLS and SLS in 3GPP LTE Downlink
Ishtiaq Ahmad,Zeeshan Kaleem,KyungHi Chang 한국통신학회 2013 한국통신학회 학술대회논문집 Vol.2013 No.1
This paper provides a link and system level study of the downlink using OFDMA techniques based on LTE systems. At the link level, the Block Error Rate (BLER) performance curves are generated and 10 % points of BLER curves, calculated under SISO AWGN channel, are considered as reference to generate the SNR-to-CQI mapping. These mapping results are used in system level simulator (SLS) via MIESM link to system interface. Then the UE throughput is evaluated by considering proportional fair (PF), round robin (RR), and best CQI schedulers at different values of UE throughput CDF. In this paper we analyze that the PF scheduler outperforms other schedulers in fairness and average throughput, while the best CQI scheduler performs good under high SINR region. The RR is the best choice when resource allocation is to be done without considering any kind of channel condition.
QoS Priority Based Femtocell User Power Control for Interference Mitigation in 3GPP LTE-A HetNet
Ishtiaq Ahmad(이쉬티아크),Zeeshan Kaleem(지산),KyungHi Chang(장경희) 한국통신학회 2014 韓國通信學會論文誌 Vol.39 No.2(네트워크)
In recent years, development of femtocells are receiving considerable attention towards increasing the network coverage, capacity, and improvement in the quality of service for users. In 3GPP LTE-Advanced (LTE-A) system, to efficiently utilize the bandwidth, femtocell and macro cell uses the same frequency band, but this deployment poses a technical challenge of cross-tier interference to macro users. In this paper, the novel quality of service based fractional power control (QoS-FPC) scheme under the heterogeneous networks environment is proposed, which considers the users priority and QoS-requirements during the power allocation. The proposed QoS-FPC scheme has two focal points: firs, it protects the macrocell users uplink communication by limiting the cross-tier interference at eNB below a given threshold, and second, it ensures the optimization of femtocell users power allocation at each power adjustment phase. Performance gain is demonstrated with extensive system-level simulations to show that the proposed QoS-FPC scheme significantly decreases the cross-tier intereference and improves the overall users throughput.