Programmable modem apparatus for transmitting and receiving digital data, design method and use method for the modem
First Claim
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1. A system for transmitting and receiving signals, comprising:
- a digital integrated circuit having a transmitter which generates first baseband signals, said transmitter having a first plurality of circuits comprising a converter coupled to receive parallel input data signals and which converts said parallel intput data to serial data, a spreader, an over-sampling filter, a gain control, and an up-converter which converts said first baseband signals to first intermediate frequency signals;
a receiver having a plurality of circuits to generate a second plurality of output data signals, said plurality of circuits comprising a down-converter to convert second signals at an intermediate frequency to second baseband signals, a decimating filter, a gain control, and a correlator which generates said plurality of output data signals;
a clock generator coupled to said transmitter and said receiver, said clock generator having at least one numerically controlled oscillator;
at least one memory mapped memory which provides storage locations for programming of said digital integrated circuit;
a phase error measuring module which measures a phase error between an external signal and one of said plurality of output data signals;
a processor coupled to said digital integrated circuit, said processor writing parameters to said plurality of memory elements and reading said plurality of output data signals and the phase error; and
a memory mapped interface coupled between said processor and said digital integrated circuit.
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Abstract
The programmable modem for digital data of the present invention provides a highly programmable, digital modem implemented in an integrated circuit which can be customized to specific applications. The programmable modem uses spread spectrum techniques and is specifically programmable to alter the parameters of the modem to improve performance. The present invention also provides a systematic method and development kit to provide rapid customization of a modem for a particular application or for rapid specification of a high-performance application specific integrated circuit mode.
121 Citations
31 Claims
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1. A system for transmitting and receiving signals, comprising:
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a digital integrated circuit having a transmitter which generates first baseband signals, said transmitter having a first plurality of circuits comprising a converter coupled to receive parallel input data signals and which converts said parallel intput data to serial data, a spreader, an over-sampling filter, a gain control, and an up-converter which converts said first baseband signals to first intermediate frequency signals;
a receiver having a plurality of circuits to generate a second plurality of output data signals, said plurality of circuits comprising a down-converter to convert second signals at an intermediate frequency to second baseband signals, a decimating filter, a gain control, and a correlator which generates said plurality of output data signals;
a clock generator coupled to said transmitter and said receiver, said clock generator having at least one numerically controlled oscillator;
at least one memory mapped memory which provides storage locations for programming of said digital integrated circuit;
a phase error measuring module which measures a phase error between an external signal and one of said plurality of output data signals;
a processor coupled to said digital integrated circuit, said processor writing parameters to said plurality of memory elements and reading said plurality of output data signals and the phase error; and
a memory mapped interface coupled between said processor and said digital integrated circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A signal receiving system comprising:
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a receiver chain with a down-converter, a receiver filter, and a gain control;
a reciever chain clock generator coupled to said receiver chain;
means for programming said receiver chain and said clock generator;
a processor programmed to complete pilot demodulation, traffic demodulation and noise estimation. - View Dependent Claims (18, 19, 20, 22)
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21. A method for increasing signal data rate of a transmission and reception system without increasing the transmission bandwidth, comprising the steps of:
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dividing the input data signal among a plurality of parallel segments of transmission data;
spreading each of the plurality of parallel segments to form parallel spread signals using orthogonal or semi-orthogonal PN codes;
summing the parallel spread signals to generate a sum signal;
filtering the sum signal to generate a first baseband signal;
transmitting said baseband signal; and
receiving said baseband signal in a receiver with parallel correlators synchronized to despread said sum signal.
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23. A modem development kit, comprising:
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a programmable modem which receives input data signals and modulates and up-converts said input data signals into first intermediate frequency signals and which demodulates and down-converts second intermediate frequency signals into output data signals, comprising;
a first transmitter chain which generates baseband signals, said transmitter chain having a converter coupled to receive input data and convert said input data into first serial baseband signals, a spreader, an over-sampling filter, a gain control, and an up-converter with a programmable frequency which converts said baseband signals to said first intermediate frequency signals, a receiver chain which generates a plurality of output data signals, said receiver chain having a down-converter with a programmable frequency which converts said second intermediate frequency signals to second baseband signals, a decimating filter, a gain control, and a correlator to convert said second baseband signals into said plurality of output data signals, a clock generator coupled to said transmitter chain and to said receiver chain, said clock generator having at least one numerically controlled oscillator;
a programmable digital signal processor;
a field programmable gate array chip;
an analog to digital converter; and
a digital to analog converter;
a radio to up-convert said first intermediate frequency signals to a first radio frequency signal, and to convert a second radio frequency signal to said second intermediate frequency signal;
an external programming device coupled to said programmable modem, to said digital signal processor and to said field programmable gate array, said external programming device providing programming for said digital signal processor, for configuring said field programmable gate array chip, and for said programmable modem;
and means for initializing said modem development kit;
means for monitoring and means for controlling said modem development kit; and
an interface between said external programming device and said programmable modem. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31)
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Specification