Performance evaluation of 8PSK at 450 Mbps through TDRSS

A research team at New Mexico State University (NMSU) has been investigating the performance of high rate uncoded octal phase-shift keying (8PSK) through NASA´s Telemetry and Data Relay Satellite System (TDRSS). In order to ensure that NASA can support high data rate programs through the TDRSS, the error-rate performance of 8PSK operated through the link at 450 Mbps was measured by NMSU. The data rate was selected for two reasons. First it is a candidate data rate specified for future LANDSAT programs. Second it exhibits a transmit bandwidth of 300 MHz, which adequately stresses the 225 MHz channel bandwidth. Although no coding was employed, the results gathered allow conclusions to be made about the performance of such systems-it was shown in an earlier investigation by NMSU that coding is unaffected by the channel. As is shown, with pre-equalization the performance of the high rate 8PSK is approximately 2 dB of the theoretical value at an error rate of 1×10^-3. Also included, is the projected performance of the system with the NASA standard Reed Solomon RS(255,223) code which was calculated based on the measured error rates. Thus, with the NASA standard Reed Solomon RS(255,223) code. It is possible to obtain bit error rates of the order 1×10^-7 while still maintaining high data throughput of almost 400 Mbps at an Eb/No of 12 dB