Title :
On the power spectral density of SGLS and USB waveforms
Author :
Wang, Charles C. ; Nguyen, Tien M. ; Yoh, James
Author_Institution :
Aerosp. Corp., Los Angeles, CA, USA
Abstract :
Most of the DoD satellites utilize the Space-to-Ground Link Subsystem (SGLS) for tracking, telemetry, and command (TT and C) controls. The standard SGLS waveform uses a phase modulation (PM) scheme on the combined PCM/FSK/AM signal and pseudo-random noise (PRN) square wave signal for command and ranging, respectively. The SGLS uplink operates in the 1755-1850 MHz (L-band), while the downlink operates in the 2200-2290 MHz (S-band). On the other hand, the non-DoD satellites for other various governmental agencies primarily use Unified S-Band (USB) for their TT and C links. Two waveforms, PCM/PSK/PM and PCM/PM/Bi-Phase, are mainly used in the USE for command along with either PRN squarewave or sinusoidal tone for ranging. Due to a high demand of utilizing the L-band for the mobile satellite services, the government has been thinking of migrating its SGLS uplink from L-band to USB to avoid the increasing radio frequency interference (RFI) from/to other mobile satellite systems. Such a migration raises a concern with respect to interference between the immigrated and existing links. To study the RFI impact, the power spectrum density (PSD) of both SGLS and USE waveforms and their respective bandwidth efficiency need to be studied. This paper derives the PSD for the SGLS and USB waveforms and compares their respective occupied bandwidths
Keywords :
command and control systems; frequency allocation; military communication; mobile satellite communication; phase modulation; pulse code modulation; satellite tracking; telemetry; 1755 to 1850 MHz; 2200 to 2290 MHz; DoD satellites; L-band; PCM/FSK/AM signal; PCM/PM/Bi-Phase; PCM/PSK/PM; PRN squarewave; RFI impact; S-band; SGLS; SGLS uplink; Space-to-Ground Link Subsystem; USB waveforms; bandwidth efficiency; command; downlink; mobile satellite services; non-DoD satellites; phase modulation; power spectral density; power spectrum density; pseudo-random noise square wave signal; radio frequency interference; sinusoidal tone; telemetry; tracking; Bandwidth; Frequency shift keying; L-band; Phase change materials; Phase modulation; Phase noise; Radiofrequency interference; Satellite broadcasting; Telemetry; Universal Serial Bus;
Conference_Titel :
Aerospace Conference, 1999. Proceedings. 1999 IEEE
Conference_Location :
Snowmass at Aspen, CO
Print_ISBN :
0-7803-5425-7
DOI :
10.1109/AERO.1999.793154
