System and apparatus for cascading and redistributing HDTV signals

• US 8,665,143 B2
• Filed: 01/11/2012
• Issued: 03/04/2014
• Est. Priority Date: 03/17/2008
• Status: Expired due to Fees

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Wi-LAN Inc.
• Inventors: Wu, Shiquan, Collings, Timothy D., Yee, Jung
• Primary Examiner(s): Ng, Fan
• Application Number:
  US13/348,319
• Publication Number:
  US 20120212628A1
• Time in Patent Office: 783 Days
• Field of Search: 370310-340, 455/403, 455/422.1, 455/450, 455/454, 342/175, 342/192
• US Class Current: 342/175
• CPC Class Codes: H04H 20/02 Arrangements for relaying broadcast information
• CPC Class Codes: H04H 20/33 by plural channels
• CPC Class Codes: H04H 20/42 Arrangements for resource management

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.

Claims

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

<sub>α

,τ</sub>

(t) providing a concentration of an energy of the cells, in both time and frequency within a finite interval, according to this equation;

∫

ψ

<sub>α

,τ</sub>

(t)dt=0.

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

<sub>α

,τ</sub>

(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.

3. 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 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]; and

a 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.

4. 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 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]; and

a 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.

5. 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 the scanning specified spectrum sections uses a wavelet function ψ

<sub>α

,τ</sub>

(t) selected to concentrate an energy of the cell, in both time and frequency within a finite interval, according to this equation;

∫

ψ

<sub>α

,τ</sub>

(t)dt=0.

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

<sub>α

,τ</sub>

(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.

7. 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 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.