Available at: http://digitalcommons.calpoly.edu/theses/398
Date of Award
MS in Electrical Engineering
New communication protocols intended for large distances, including low orbit and deep space, can be inherently difficult to evaluate since trial implementations are often impractical. In order to accurately measure the performance of a new protocol, it is important to evaluate it in an environment that most closely matchs that in which it will be used. This thesis demonstrates the ability to emulate a space communications channel through digitizing a transmission centered at an intermediate frequency of 70 MHz with a bandwidth of 24 MHz, digitally introducing the characteristics of a transmission through space, and reconstructing the digital data to its analog counterpart. Delay, Doppler shift, Gaussian noise, and fading are among the most prevalent characteristics of such a channel, and thus were the focus of this thesis. Special care was given to the design of each digital and analog component to maintain the integrity of the original signal by minimizing all undesired noise introduced. The final design can accurately produce a given dynamic transmission signature or continually output a static set of channel characteristic parameters to test new communication protocols.