• OFDM Performance on Aeronautical Channnels

      Dean, Richard; Kamirah, Daniel K.; Morgan State University (International Foundation for Telemetering, 2009-10)
      This paper provides an introduction to the Orthogonal Frequency Division Multiplexing (OFDM) scheme which has been proposed for future aeronautical telemetry applications. OFDM offers the potential for high data rates on radio channels with multipath such as aeronautical telemetry channels. This paper provides in introduction to OFDM and demonstrates how orthogonality is maintained over multipath channels by the introduction of a guard band and by the inclusion of a cyclic prefix. The simulation of OFDM in multipath is simulated and performance results are presented that show the degradation of this scheme on a multipath channel with and without the guard band and the cyclic prefix.
    • Performance Comparison of OFDM and DSSS on Aeronautical Channels

      Cole-Rhodes, Arlene; Dean, Richard; Ehichioya, Daniel; Golriz, Arya; Morgan State University (International Foundation for Telemetering, 2009-10)
      This paper develops a performance framework for OFDM by contrasting its performance with Direct Sequence Spread Spectrum (DSSS) over aeronautical channels. Each of the OFDM and DSSS modulated simulations are put through the channel and compared on terms of signal to noise ratio (SNR) versus bit error rate. The simulation will show that DSSS will have better power efficiency on multipath channels because the rake receiver adds all multipath components to strengthen the receiver. By contrast OFDM with an equalizer will have better spectrum efficiency results where QAM modulation of multiple tones allows for high data rates in a limited bandwidth. This work develops a framework for contrasting the performance of the rake receiver and the equalizer for operation on multipath channels. By comparing these schemes on various channels the choice of OFDM for iNET can be clearly understood and evaluated.
    • Proposed iNET Network Security Architecture

      Dean, Richard; Dukes, Renata; Morgan State University (International Foundation for Telemetering, 2009-10)
      Morgan State University's iNET effort is aimed at improving existing telemetry networks by developing more efficient operation and cost effectiveness. This paper develops an enhanced security architecture for the iNET environment in order to protect the network from both inside and outside adversaries. This proposed architecture addresses the key security components of confidentiality, integrity and authentication. The security design for iNET is complicated by the unique features of the telemetry application. The addition of encryption is complicated by the need for robust synchronization needed for real time operation in a high error environment.
    • Traceable Enterprise Information Security Architecture Methodology

      Dean, Richard; Brown-Moorer, Charlotte A.; Morgan State University (International Foundation for Telemetering, 2009-10)
      With the introduction of networking into telemetry applications, these systems have become increasingly complex. This imposes significant strain on information security for architecture designs. It has been recognized that an organized or structured approach to developing security architectures is needed. Several enterprise architecture frameworks are available today that address system complexity. However they fall short of addressing security at a high enough level in the enterprise and address security too late in the design process. In this paper a methodology is proposed that bridges the gap between security requirements and architecture design development at the enterprise level. This approach is consistent with and traceable to the original needs of the customer. This paper introduces a systems engineering approach to develop an enterprise level methodology, and presents a worked example of this approach for the integrated Network Enhanced Telemetry system.