System and apparatus for cascading and redistributing HDTV signals
First Claim
Patent Images
1. A gateway for redistributing an information signal to a user device within a service area, comprising:
- a spectrum detector capable of monitoring a specified spectrum and identifying a section of a specified spectrum including a plurality of cells of white space sufficient to accommodate a required bandwidth associated with the information signal,a transmitter for transmitting to the user device the information signal over the plurality of cells identified in the section of the spectrum; and
a control device for transmitting and receiving bidirectional control messages,wherein the spectrum detector comprises;
a tunable RF module for scanning specified spectrum sections and capturing any wireless signal present in the spectrum sections;
an analog to digital converter for converting the captured wireless signal to a digital signal;
a wavelet coefficient calculator for measuring an energy of the digital signal in each of a plurality of cells formed within the specified spectrum sections; and
a sorting unit for selecting the k pieces of white space from the cells where the energy of the digital signal is under a threshold,wherein the wavelet coefficient calculator uses a wavelet function ψ
α
,τ
(t) providing a concentration of an energy of the cells, in both time and frequency within a finite interval, according to this equation;
∫
ψ
α
,τ
(t)dt=0.
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Accused Products
Abstract
Redistribution of multimedia signals or the like within a service area is performed by identifying one or more pieces of white space in the VHF/UHF spectrum, selecting a carrier frequency for each piece of white space spectrum, parsing the signal into a like number of components and modulating each component over a carrier frequency. The receiving device performs the reverse operation for reconstructing the signal.
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Citations
7 Claims
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1. A gateway for redistributing an information signal to a user device within a service area, comprising:
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a spectrum detector capable of monitoring a specified spectrum and identifying a section of a specified spectrum including a plurality of cells of white space sufficient to accommodate a required bandwidth associated with the information signal, a transmitter for transmitting to the user device the information signal over the plurality of cells identified in the section of the spectrum; and a control device for transmitting and receiving bidirectional control messages, wherein the spectrum detector comprises; a tunable RF module for scanning specified spectrum sections and capturing any wireless signal present in the spectrum sections; an analog to digital converter for converting the captured wireless signal to a digital signal; a wavelet coefficient calculator for measuring an energy of the digital signal in each of a plurality of cells formed within the specified spectrum sections; and a sorting unit for selecting the k pieces of white space from the cells where the energy of the digital signal is under a threshold, wherein the wavelet coefficient calculator uses a wavelet function ψ
α
,τ
(t) providing a concentration of an energy of the cells, in both time and frequency within a finite interval, according to this equation;
∫
ψ
α
,τ
(t)dt=0.
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2. A gateway for redistributing an information signal to a user device within a service area, comprising:
-
a spectrum detector capable of monitoring a specified spectrum and identifying a section of a specified spectrum including a plurality of cells of white space sufficient to accommodate a required bandwidth associated with the information signal, a transmitter for transmitting to the user device the information signal over the plurality of cells identified in the section of the spectrum; and a control device for transmitting and receiving bidirectional control messages, wherein the spectrum detector comprises; a tunable RF module for scanning specified spectrum sections and capturing any wireless signal present in the spectrum sections; an analog to digital converter for converting the captured wireless signal to a digital signal; a wavelet coefficient calculator for measuring an energy of the digital signal in each of a plurality of cells formed within the specified spectrum sections; and a sorting unit for selecting the k pieces of white space from the cells where the energy of the digital signal is under a threshold, wherein the wavelet coefficient calculator is capable of measuring an energy of the digital signal in each cell by calculating a wavelet coefficient for the digital signal detected in the respective cell, wherein the wavelet coefficient calculator uses shifted variants of a wavelet function ψ
α
,τ
(t), wherein the wavelet coefficient calculator obtains the shifted variants by performing integer shifts of an energy concentration center of the wavelet function, such that adjacent shifted waveforms are orthogonal.
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3. A gateway for redistributing an information signal to a user device within a service area, comprising:
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a spectrum detector capable of monitoring a specified spectrum and identifying a section of a specified spectrum including a plurality of cells of white space sufficient to accommodate a required bandwidth associated with the information signal, a transmitter for transmitting to the user device the information signal over the plurality of cells identified in the section of the spectrum; and a control device for transmitting and receiving bidirectional control messages, wherein the transmitter comprises; a baseband processor for converting the information signal into a baseband-signal and parsing the baseband signal into n signal components where n is an integer, nε
[1;
k]; anda distributor unit with k branches for modulating n carrier signals, each carrier signal having a frequency corresponding to a respective piece of white space, with a signal component, and broadcasting n RF signal components over the respective piece of white space, wherein each branch of the distributor unit modulates the baseband signal whenever a 6 MHz piece of spectrum has been identified by the spectrum detector.
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4. A gateway for redistributing an information signal to a user device within a service area, comprising:
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a spectrum detector capable of monitoring a specified spectrum and identifying a section of a specified spectrum including a plurality of cells of white space sufficient to accommodate a required bandwidth associated with the information signal, a transmitter for transmitting to the user device the information signal over the plurality of cells identified in the section of the spectrum; and a control device for transmitting and receiving bidirectional control messages, wherein the transmitter comprises; a baseband processor for converting the information signal into a baseband-signal and parsing the baseband signal into n signal components where n is an integer, nε
[1;
k]; anda distributor unit with k branches for modulating n carrier signals, each carrier signal having a frequency corresponding to a respective piece of white space, with a signal component, and broadcasting n RF signal components over the respective piece of white space, wherein for n=1, all carrier signals are modulated with the same baseband signal for obtaining spatial diversity.
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5. A method for redistributing an information signal of a specified bandwidth, within a service area, comprising:
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identifying k pieces of white space sufficient to accommodate the bandwidth of the information signal, where k is an integer, k≧
1;broadcasting the information signal over the identified k pieces of white space; and transmitting and receiving bidirectional control messages, wherein identifying k pieces comprises; scanning specified spectrum sections and capturing any wireless signal present in the specified spectrum sections; converting the captured wireless signal to a digital signal; measuring an energy of the digital signal in each of a plurality of cells formed within the specified spectrum sections; and selecting the k pieces of white space from the cells where the energy of the digital signal is under a threshold, wherein the scanning specified spectrum sections uses a wavelet function ψ
α
,τ
(t) selected to concentrate an energy of the cell, in both time and frequency within a finite interval, according to this equation;
∫
ψ
α
,τ
(t)dt=0.
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6. A method for redistributing an information signal of a specified bandwidth, within a service area, comprising:
-
identifying k pieces of white space sufficient to accommodate the bandwidth of the information signal, where k is an integer, k≧
1;broadcasting the information signal over the identified k pieces of white space; and transmitting and receiving bidirectional control messages, wherein identifying k pieces comprises; scanning specified spectrum sections and capturing any wireless signal present in the specified spectrum sections; converting the captured wireless signal to a digital signal; measuring an energy of the digital signal in each of a plurality of cells formed within the specified spectrum sections; and selecting the k pieces of white space from the cells where the energy of the digital signal is under a threshold, wherein said measuring an energy comprises measuring the energy of the digital signal in each cell by calculating a wavelet coefficient for the digital signal detected in the respective cell, and wherein calculating a wavelet coefficient uses shifted variants of the wavelet function ψ
α
,τ
(t−
τ
), and includes obtaining the shifted variants by performing integer shifts of an energy concentration center of the wavelet function, such that adjacent shifted waveforms are orthogonal.
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7. A method for redistributing an information signal of a specified bandwidth, within a service area, comprising:
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identifying k pieces of white space sufficient to accommodate the bandwidth of the information signal, where k is an integer, k≧
1;broadcasting the information signal over the identified k pieces of white space; and transmitting and receiving bidirectional control messages, wherein said broadcasting the information signal comprises; converting the information signal into a baseband signal; parsing the baseband signal into n signal components, where n is an integer nε
[1;
k];selecting a carrier frequency for each of the k pieces of white space and providing k carrier signals of a respective carrier frequency; modulating each of the k carrier signals with a signal component, and broadcasting the k signal components over the respective piece of white space, wherein for n=1, all carrier signals are modulated with the same baseband signal for obtaining spatial diversity.
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Specification