Homodyne radio architecture for direct sequence spread spectrum data reception
First Claim
1. A direct sequence spread spectrum radio system, comprising:
- an input RF amplifier for receiving and amplifying a carrier signal, fO, modulated by a digital code sequence;
a local oscillator providing a signal having a frequency equal to the frequency of the carrier signal, fO ;
a first mixer receiving said modulated carrier signal and said local oscillator signal and generating a corresponding baseband output signal;
a second mixer receiving said local oscillator signal and a baseband input signal modulated by said digital code sequence and generating a corresponding output signal; and
an output RF amplifier for amplifying and transmitting said output signal.
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Accused Products
Abstract
A homodyne radio system for receiving direct sequence spread spectrum communications enables a received signal to be down-converted directly to a baseband signal. An input RF amplifier receives and amplifies a carrier signal modulated by a digital code sequence. A local oscillator provides a signal having a frequency substantially equal to the frequency of the carrier signal. A phase splitter coupled to the input RF amplifier receives the modulated carrier signal, and splits the signal into corresponding quadrature component signals. The mixer combines a first one of the quadrature component signals with the local oscillator signal to generate a first quadrature baseband output signal. A second one of the quadrature component signals is combined with the local oscillator signal shifted in phase by 90° to generate a second quadrature baseband output signal. A transmitted signal can be generated by mixing quadrature baseband input signals with the same local oscillator and phase shifted local oscillator signals.
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Citations
20 Claims
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1. A direct sequence spread spectrum radio system, comprising:
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an input RF amplifier for receiving and amplifying a carrier signal, fO, modulated by a digital code sequence; a local oscillator providing a signal having a frequency equal to the frequency of the carrier signal, fO ; a first mixer receiving said modulated carrier signal and said local oscillator signal and generating a corresponding baseband output signal; a second mixer receiving said local oscillator signal and a baseband input signal modulated by said digital code sequence and generating a corresponding output signal; and an output RF amplifier for amplifying and transmitting said output signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A direct sequence spread spectrum radio system, comprising:
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means for receiving a received signal comprising a carrier signal, fO, modulated by a digital code sequence, and for transmitting a transmitted signal comprising said carrier signal modulated by said digital code sequence; a local oscillator providing a signal having a frequency equal to said carrier frequency, fO ; first means for generating a corresponding baseband output signal from said received signal and said local oscillator signal; and second means for generating said transmitted signal from said local oscillator signal and a baseband input signal. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16)
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17. A direct sequence spread spectrum radio system, comprising:
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an antenna adapted to receive a signal comprising a carrier signal, fO, modulated by a digital code sequence, and to transmit a signal comprising said carrier signal modulated by said digital code sequence; a local oscillator providing a signal having a frequency equal to said carrier frequency, fO ; a first double balanced mixer coupled to said antenna to receive said received signal and said local oscillator signal, said first mixer generating a corresponding baseband output signal; and a second double balanced mixer coupled to said antenna to receive a baseband input signal and said local oscillator signal, said second mixer generating said transmitted signal. - View Dependent Claims (18, 19, 20)
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Specification