Roger Pierre Fabris Hoefel

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 We have developed a theoretical cross-layer model that allows assessing the goodput and delay of IEEE 802.11 local area networks (WLANs) operating simultaneously under the distributed coordination function (DCF) basic access (BA) and request-to-send/clear-to-send (RTS/CTS) medium access control (MAC) protocols under saturated traffic over correlated(More)
In this paper, we investigate the effects of transmit antenna correlation, receive antenna correlation, frequency selectivity and imperfect synchronization and channel estimation schemes on the performance of IEEE 802.11n systems with spatial expansion, receive diversity and space-time block codes. The simulations results are validated using a first order(More)
 It is developed a theoretical cross-layer model for medium access control (MAC) and physical (PHY) layer protocols of wireless local area networks (WLANs) based on the IEEE 802.11 standard. The proposed analytical expressions allow to assess the effects of distinct modulation schemes and channel models on the system performance. It is also analytically(More)
In this paper, the performance of a joint time-frequency synchronization scheme specially designed for the IEEE 802.11n amendment is analyzed. Simulation results, validated by analytical modeling, show that the proposed auto-correlation synchronization scheme is robust over frequency selective spatially correlated TGn MIMO channels impaired with frequency(More)
In this paper, we investigate the performance of Least Square (LS), Time Delay Truncation (TDT) and ModelBased (MB) channel estimation schemes specially designed to operate in a orthogonal frequency division multiplexing (OFDM) multiple input multiple output (MIMO) IEEE 802.11n system. We conclude, founded on analytical and simulation results over spatially(More)
This paper investigates the performance of IEEE 802.11ac physical layer (PHY) when the following multiple input multiple output (MIMO) detectors are implemented: Sphere Decoding (SD); QRM-Maximum Likelihood (QRM-MLD); List Minimum Mean Squared Error Successive Interference Cancellation (List MMSE-SIC); List Zero-Forcing SIC (List ZFSIC); Lattice Reduction(More)
This research deals with a study of case, unifying theoretical and practical aspects, regarding the cell-planning of Wideband Code Division Multiplexing (WCDMA) Release 99 (Rel99) and High Speed Downlink Packet Access (HSDPA) Rel. 5 networks. The used methodology, validated by the close agreement between field and numerical results for throughput and cell(More)