naa a22 4500 510797717 CHVBK 20180411083342.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s11277-013-1005-3 doi (NATIONALLICENCE)springer-10.1007/s11277-013-1005-3 Performance Analysis of Two Dimensional Spreading for OFCDM Femtocell Users Overlaid with OFDM Macrocell [Elektronische Daten] [F. Hussain, A. Anpalagan, H. Kong] Femtocells provide indoor coverage for voice and high speed data services and are self-deployed by end-users. Orthogonal frequency code division multiplexing (OFCDM) is a multi-carrier spread spectrum technique that utilizes two dimensional spreading in time and frequency domains simultaneously to improve frequency diversity and minimize multiuser access interference. In this paper, variable spreading factor (VSF)-OFCDM is employed in subcarrier allocation for femto users (FUEs) in a hybrid femto/macro network, and the effect of FUE deployment on macro users (MUEs) is studied. We evaluate the bit error rate (BER) performance of FUEs and MUEs through Monte Carlo simulation under various load conditions in noise and interference-limited scenarios. Relationship between the channel load and optimum spreading factor employed by FUEs for the given network configuration, is also analyzed. We provide various graphs showing the impact of FUE spreading factor on the MUE BER. We note that in interference-limited conditions, $$4\times 8$$ spreading $$(\text{ time}\times \text{ freq}.)$$ proves to be the best choice for macro users; and for the noise-limited case, when there are limited number of users and channel noise is dominant, $$2\times 16$$ spreading is the optimum choice for the considered hybrid network configuration. We also evaluate the effect of femto wall penetration loss on macro BER for various spreading factors. The favorable spreading factor for MUEs is tabulated for different loads and different number of subcarriers, which can be used as a deployment guide in this heterogeneous network. Springer Science+Business Media New York, 2013 Femtocells nationallicence Macrocells nationallicence OFDM nationallicence VSF-OFCDM nationallicence Two dimensional spreading nationallicence Optimum spreading factor nationallicence Hussain F. WINCORE Laboratory, Ryerson University, Toronto, Canada aut Anpalagan A. WINCORE Laboratory, Ryerson University, Toronto, Canada aut Kong H. Wireless Communication Laboratory, University of Ulsan, Ulsan, South Korea aut Wireless Personal Communications Springer US; http://www.springer-ny.com 72/1(2013-09-01), 137-158 0929-6212 72:1<137 2013 72 11277 https://doi.org/10.1007/s11277-013-1005-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11277-013-1005-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hussain F. WINCORE Laboratory, Ryerson University, Toronto, Canada aut NATIONALLICENCE 700 1- Anpalagan A. WINCORE Laboratory, Ryerson University, Toronto, Canada aut NATIONALLICENCE 700 1- Kong H. Wireless Communication Laboratory, University of Ulsan, Ulsan, South Korea aut NATIONALLICENCE 773 0- Wireless Personal Communications Springer US; http://www.springer-ny.com 72/1(2013-09-01), 137-158 0929-6212 72:1<137 2013 72 11277 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer