Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
116 words
In a satellite communication system including a plurality of mobile stations situated on the earth and a communication satellite communicatable with said mobile stations by using radio signals over a plurality of spot beams; said mobile stations each comprises a transmitter for modulating voice and data to produce a frequency-division-multiplexed (FDM) signal and transmitting said FDM signal to said communication satellite over any of the spot beams which is associated with said mobile station; and said communication satellite comprises an onboard transponder for separating FDM signals which are sent from said mobile stations from each other and then interconnecting the spot beams to transmit signals to said mobile stations for which said FDM signals are meant.
Claim 2
Dependent Claim
116 words
In a satellite communication system including a plurality of mobile stations situated on the earth and a communication satellite communicatable with said mobile stations by using radio signals over a plurality of spot beams; said mobile stations each comprises a transmitter for modulating voice and data to produce a frequency-division-multiplexed (FDM) signal and transmitting said FDM signal to said communication satellite over any of the spot beams which is associated with said mobile station; and said communication satellite comprises an onboard transponder for separating FDM signals which are sent from said mobile stations from each other and then interconnecting the spot beams to transmit signals to said mobile stations for which said FDM signals are meant.
Claim 3
Dependent Claim
73 words
A satellite communication system as claimed in claim 1, wherein said transponder comprises demultiplexing means for demultiplexing the received FDM signals on a channel basis, baseband matrix means for connecting outputs of said demultiplexing means to the beams over which said FDM signals are to be transmitted, and transmitting means for time-division-multiplexing outputs of said baseband matrix means to produce a transmit frame and transmitting said transmit frame as a time-division-multiplexed (TDM) signal.
Claim 4
Dependent Claim
49 words
A satellite communication system as claimed in claim 2, wherein said mobile stations each comprises a receiver for selecting a channel signal to be received out of the TDM signal which is sent from said transmitting means of said transponder, and demodulating said channel signal to regenerate a signal.
Claim 5
Dependent Claim
37 words
A satellite communication system as claimed in any of claims 1 to 3, wherein said transponder further comprises a receive antenna for receiving the FDM signals and a receiver for receiving an outout of said receive antenna.
Claim 6
Dependent Claim
43 words
A satellite communication system as claimed in any of claims 2 to 4, wherein said demultiplexing means of said transponder comprises a transmultiplexer type demultiplexer for separating outputs of said receiver on a channel basis to convert said outputs into parallel baseband signals.
Claim 7
Dependent Claim
59 words
A satellite communication system as claimed in any of claims 2 to 5, wherein said baseband matrix means of said transponder comprises a baseband switch matrix for connecting outputs of said transmultiplexer type demultiplexer to sections for transmitting the beams which are individually associated with said outputs, and a baseband switch matrix controller for controlling said baseband switch matrix.
Claim 8
Dependent Claim
127 words
A satellite communication system as claimed in any of claims 2 to 6, wherein said transmitting means of said transponder comprises a time division multiplexer for time-division-multiplexing parallel outputs of said baseband switch matrix with a high-speed timing signal, a unique word (UW) generator for generating a unique word, a frame synthesizer supplied with outputs of said time division multiplexers and an outputs of said UW generator for inserting a unique word at each multiplexing period to form a frame, a modulator for modulating a transmit carrier with an output of said frame synthesizer, a high-power amplifier for high-power amplifying an output of said modulator, a transmitter, and a transmit antenna for transmitting an output of said transmitter to a downlink of any of the spot beams.