US 7,321,641 B2
Baseband time-domain communications system
Andrew Alfred Moulthrop, Los Angeles, Calif. (US); Michael Steven Muha, Torrance, Calif. (US); and Christopher Patrick Silva, Rancho Palos Verdes, Calif. (US)
Assigned to The Aerospace Corporation, El Segundo, Calif. (US)
Filed on Jun. 03, 2004, as Appl. No. 10/860,232.
Prior Publication US 2005/0271164 A1, Dec. 08, 2005
Int. Cl. H03D 3/22 (2006.01)
U.S. Cl. 375—332 20 Claims
OG exemplary drawing
 
1. A system for determining lowpass equivalencies of generated baseband signals, the system comprising,
carrier generator means for providing a local carrier,
phase shifter means for phase shifting the local carrier by phase shifts to provide phase shifted carriers, the phase shifts being 0°, 90°, θ and θ+π/2 where θ=π/4+mπ/2 where m is an integer,
downconverter means for downconverting an input signal into the generated baseband signals, the input signal having a carrier modulated by an input baseband signal, the phase shifted carriers being phase shifted replicas of the carrier, and
processor means for receiving the generated baseband signals, the processor means for determining the lowpass equivalencies of the generated baseband signals.