Rake receiving apparatus for direct sequence code division multiple access system
First Claim
1. A rake receiving apparatus for a direct sequence code division multiple access communication system comprising:
- a radio frequency receiving unit for receiving a radio frequency signal via an antenna and converting the received radio frequency signal into a baseband signal;
analog/digital converting means for converting the analog signal, which is the baseband signal from the radio frequency receiving unit, into a digital signal;
first pseudo noise code generating means for generating and outputting pseudo noise codes;
searching means for receiving the digital signal from the analog/digital converting means and the pseudo noise codes from the first pseudo noise code generating means, thereby outputting pseudo noise code phases respectively corresponding to multipaths;
combiner controlling means for receiving the output signal from the searching means, thereby outputting a signal adapted to have select components combined together from the output signal from the analog/digital converting means;
multipath combiner means for receiving the output signal from the combiner controlling means and the output signal from the analog/digital converting means, selecting multipaths from the output signal from the analog/digital converting means based on the output signal from the combiner controlling means, and combining the selected multipaths;
second pseudo noise code generating means for receiving the output signal from the combiner controlling means, thereby generating pseudo noise codes;
demodulating means for receiving the output signal from the second pseudo noise code generating means and the output signal from the combiner means, thereby demodulating data and outputting the demodulated data; and
synchronization tracking means for receiving the output signal from the second pseudo noise code generating means and the output signal from the combiner means, thereby recovering a synchronization of the pseudo noise codes generated from the first pseudo noise generating means.
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Abstract
A rake receiving apparatus used in communication systems using a DS/CDMA (direct sequence code division multiple access) system, wherein a single demodulating finger is used for a plurality of multipath signals, thereby being capable of not only greatly reducing the complexity of its demodulators, but also achieving an improvement in performance where a large number of multipaths are used. The apparatus includes a searcher for extracting the phases of pseudo noise codes searcher for pseudo corresponding in number to existing multipaths, a combiner controlling unit for selecting those of the phase values from the searcher to be combined together, a combiner for combing selected phase values together, a pseudo noise code generator for generating pseudo noise codes, a demodulator for reversely sequencing its input signal using the output from the pseudo noise code generator, thereby recovering data, and a synchronization tracer for controlling the pseudo noise code generator such that the pseudo noise code phase of the pseudo noise code generator coincides with the pseudo noise code phase of the input signal at the synchronization tracer.
28 Citations
11 Claims
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1. A rake receiving apparatus for a direct sequence code division multiple access communication system comprising:
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a radio frequency receiving unit for receiving a radio frequency signal via an antenna and converting the received radio frequency signal into a baseband signal; analog/digital converting means for converting the analog signal, which is the baseband signal from the radio frequency receiving unit, into a digital signal; first pseudo noise code generating means for generating and outputting pseudo noise codes; searching means for receiving the digital signal from the analog/digital converting means and the pseudo noise codes from the first pseudo noise code generating means, thereby outputting pseudo noise code phases respectively corresponding to multipaths; combiner controlling means for receiving the output signal from the searching means, thereby outputting a signal adapted to have select components combined together from the output signal from the analog/digital converting means; multipath combiner means for receiving the output signal from the combiner controlling means and the output signal from the analog/digital converting means, selecting multipaths from the output signal from the analog/digital converting means based on the output signal from the combiner controlling means, and combining the selected multipaths; second pseudo noise code generating means for receiving the output signal from the combiner controlling means, thereby generating pseudo noise codes; demodulating means for receiving the output signal from the second pseudo noise code generating means and the output signal from the combiner means, thereby demodulating data and outputting the demodulated data; and synchronization tracking means for receiving the output signal from the second pseudo noise code generating means and the output signal from the combiner means, thereby recovering a synchronization of the pseudo noise codes generated from the first pseudo noise generating means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A rake receiving apparatus for a direct sequence code division multiple access communication system comprising:
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a radio frequency receiving unit for receiving a radio frequency signal via an antenna and converting the received radio frequency signal into an intermediate frequency signal; analog/digital converting means for converting the analog signal, which is the intermediate frequency signal from the radio frequency receiving unit, into a digital signal; digital down-converting means for frequency-down-converting the digital signal received frown the analog/digital converting means into a baseband signal; sample delay means for receiving the baseband signal from the digital down-converting means, and sequentially outputting first output signals while delaying the first output signals a predetermined time interval; first pseudo noise code generating means for generating and outputting first pseudo noise codes; searching means for receiving the baseband signal from the digital down-converting means and the first pseudo noise codes from the first pseudo noise code generating means, thereby outputting pseudo noise code phases respectively as second output signals corresponding to multipaths; combiner controlling means for receiving the second output signals from the searching means and outputting third output signals adapted to select as sequentially output from the sample delay means; sample selecting means for receiving the first output signals sequentially output from the sample delay means and the third output signals from the combiner controlling means and selectively outputting the first output signals received from the sample delay means based on the third output signals received from the combiner controlling means; a combiner for receiving the first output signals selectively output from the sample selecting means and combining the first output signals to form a fourth output signal; second pseudo noise code generating means for receiving a fifth output signal from the combiner controlling means, thereby generating second pseudo noise codes; demodulating means for receiving the second pseudo noise codes from the second pseudo noise code generating means and the fourth output signal from the combiner means, thereby demodulating data and outputting the demodulated data; and synchronization tracking means for receiving the second pseudo noise codes from the second pseudo noise code generating means and the fourth output signal from the combiner means, thereby recovering a synchronization of the first pseudo noise codes generated from the first pseudo noise generating means. - View Dependent Claims (9, 10, 11)
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Specification