International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / Space agencies are under pressure to utilize better bandwidth-efficient communication methods due to the actual allocated frequency bands becoming more congested. Budget reductions is another problem that the space agencies must deal with. This budget constraint results in simpler spacecraft carrying less communication capabilities and also the reduction in staff to capture data in the earth stations. It is then imperative that the most bandwidth efficient communication methods be utilized. This paper gives the results of a computer simulation study on 8 Level Phase Shift Keying (8PSK) modulation with respect to bandwidth, power efficiency, spurious emissions, interference susceptibility and the non-constant envelope effect through a non-linear channel. The simulations were performed on a Signal Processing Worksystem (SPW: software installed on a SUN SPARC 10 Unix Station and Hewlett Packard Model 715/100 Unix Station). This work was conducted at New Mexico State University (NMSU) in the Center for Space Telemetry and Telecommunications Systems in the Klipsch School of Electrical and Computer Engineering.