Abstract: An inverter circuit that includes a FET input transistor having a gate, a source, a drain and a FET output transistor having a gate, a source and a drain. The circuit further includes first and second power lines and a constant current source. No transistor other than the input and output transistors is coupled between the input and output terminals. Also, a Bipolar inverter circuit, a FET NAND/AND function circuit, a Bipolar NAND/AND function circuit, a FET differential circuit and a Bipolar differential circuit using the inverter circuit as a building block.

Abstract: Disclosed is a system and method for modulating and demodulating a data signal. The system includes a number of configurable multi-rate signal processing modules coupled to a local interface. The system also includes a control module coupled to the local interface, the control module being adapted to shuttle a number of data symbols among the configurable multi-rate processing modules according to a predefined modulation or demodulation scheme. The system can advantageously be configured to perform one of multiple modulation or demodulation schemes.

Abstract: A method and a system for multi-user communications in a CDMA-based satellite network. An uplink RF signal containing a coded user message that has been differentially phase encoded and spread using a Walsh function and a pseudo-random number (PN) sequence for the uplink, is received by a satellite receiver. The received uplink RF signal is non-coherently quadrature demodulated and then despread using the uplink PN sequence and Walsh function. The differential phase signal carrying the coded user message is regenerated onboard the satellite by phase comparison and switched to a selected downlink transmitter. The quadrature components of the differential phase signal are then respread using a Walsh function and a PN sequence for the downlink, followed by quadrature modulation for transmission to a terrestrial receiver. The received downlink RF signal is coherently quadrature demodulated and despread using the PN sequence and Walsh function for the downlink.