DATA FEEDBACK FOR BROADCAST APPLICATIONS

1 . A method comprising:

identifying at least one channel currently available in a digital broadcast spectrum;

transmitting data via the at least one identified channel of the digital broadcast spectrum, wherein the transmitted data complies with a digital broadcast format;

receiving a representation of the data;

comparing, by at least one device, at least a portion of the received representation of the data to at least a portion of the transmitted data; and

determining, by the at least one device, whether to adjust a broadcast transmission parameter or a data transformation parameter for use in subsequent data communication based upon the comparison.

2 . The method of claim 1 , further comprising:

transforming the data into the digital broadcast format; and

modulating the transformed data prior to its transmission.

3 . The method of claim 2 , wherein determining whether to adjust the broadcast transmission parameter or the data transformation parameter comprises determining whether to adjust a coding parameter for use in subsequent data transformation operations.

4 . The method of claim 1 , wherein:

identifying the at least one channel comprises identifying the at least one channel in an unused portion of a digital broadcast television spectrum; and

transmitting the data comprises transmitting the data according to the digital broadcast format via the at least one identified channel of the digital broadcast television spectrum.

5 . The method of claim 1 , wherein the digital broadcast format comprises an ATSC (Advanced Television Systems Committee) format, a T-DMB (Terrestrial Digital Multimedia Broadcasting) format, a DVB (Digital Video Broadcasting) format, an Integrated Services Digital Broadcasting Terrestrial (ISDB-T) format, or a Moving Picture Experts Group Transport Stream (MPEG-TS) format.

6 . The method of claim 1 , wherein identifying the at least one channel comprises identifying television band white space.

7 . The method of claim 1 , wherein the data comprises at least one of audio data, video data, text data, speech data, graphics data, and ancillary interactivity data.

8 . The method of claim 1 , wherein comparing at least the portion of the received representation of the data to at least the portion of the transmitted data comprises comparing one or more samples of the received representation of the data to corresponding one or more samples of the transmitted data.

9 . The method of claim 1 , wherein determining whether to adjust the broadcast transmission parameter or the data transformation parameter comprises determining whether to adjust a transmit power used for subsequent data transmission.

10 . The method of claim 9 , wherein determining whether to adjust the transmit power comprises determining whether any differences between at least the portion of the received representation of the data and at least the portion of the transmitted data exceed a defined threshold indicative of signal distortion, and wherein the method further comprises:

transmitting additional data via the at least one identified channel with increased power when the differences exceed the defined threshold.

11 . The method of claim 10 , further comprising:

receiving a representation of additional data;

comparing at least a portion of the representation of the additional data to at least a portion of the transmitted additional data;

responsive to determining that any differences between at least the portion of the received representation of the additional data and at least the portion of the transmitted additional data continue to exceed the defined threshold, identifying at least one other channel currently available in the digital broadcast spectrum; and

transmitting further data via the at least one other identified channel.

12 . The method of claim 11 , further comprising:

repeating the transmitting of additional data with increased power multiple iterations prior to transmitting further data via the at least one other identified channel.

13 . The method of claim 10 , wherein determining whether any differences between at least the portion of the received representation of the data and at least the portion of the transmitted data exceed the defined threshold comprise determining that a defined number of data packets included in at least the portion of the transmitted data are not included in at least the portion of the received representation of the data.

14 . The method of claim 1 , wherein:

transmitting the data comprises inserting a plurality of audio watermarks into the data prior to transmission;

receiving the representation of the data comprises receiving representations of the audio watermarks; and

comparing comprises comparing the received representations of the audio watermarks to the audio watermarks contained in the transmitted data.

15 . The method of claim 14 , wherein the audio watermarks comprises at least one of a pseudo-noise spread-spectrum sequence and inaudible audio.

16 . The method of claim 14 , wherein determining whether to adjust the broadcast transmission parameter or the data transformation parameter comprises determining whether to adjust a transmit power used for subsequent data transmission based upon whether any differences between the received representations of the audio watermarks to the audio watermarks contained in the transmitted data exceed a defined threshold.

17 . The method of claim 14 , wherein comparing the received representations of the audio watermarks to the audio watermarks contained in the transmitted data comprises:

identifying locations of the representations of the audio watermarks within the received representation of the data; and

determining at least the portion of the received representation of the data that is to be compared to at least the portion of the transmitted data based upon the identified locations.

18 . The method of claim 1 , further comprising:

estimating an expected amount of signal distortion in the received representation of the data, and wherein the comparing comprises accounting for the expected amount of signal distortion in the received representation of the data.

19 . The method of claim 1 , wherein comparing at least the portion of the received representation of the data to at least the portion of the transmitted data comprises comparing at least the portion of the received representation of the data to at least the portion of the transmitted data to estimate at least one of a signal round-trip propagation delay, one or more multipath characteristics, a loudness value, and one or more room equalization characteristics.

20 . The method of claim 1 , wherein the transmitted data is part of at least one multimedia data stream, and wherein the representation of the data includes a representation of only a subset of data included within the at least one multimedia data stream.

21 . A communication system, comprising:

one or more processors;

a channel identifier operable by the one or more processors to identify at least one channel currently available in a digital broadcast spectrum;

a transmitter operable by the one or more processors to transmit data via the at least one identified channel of the digital broadcast spectrum, wherein the transmitted data complies with a digital broadcast format;

a data receiver/feedback unit operable by the one or more processors to receive a representation of the data and compare at least a portion of the received representation of the data to at least a portion of the transmitted data,

wherein the one or more processors are configured to determine whether to adjust a broadcast transmission parameter or a data transformation parameter for use in subsequent data communication based upon the comparison.

22 . The communication system of claim 21 , further comprising:

a transformation unit operable by the one or more processors to transform the data into the digital broadcast format; and

a modulator operable by the one or more processors to modulate the transformed data prior to its transmission.

23 . The communication system of claim 22 , wherein the one or more processors are configured to determine whether to adjust the broadcast transmission parameter or the data transformation parameter at least by determining whether to adjust a coding parameter for use in subsequent data transformation operations.

24 . The communication system of claim 21 , wherein:

the channel identifier is operable to identify the at least one channel in an unused portion of a digital broadcast television spectrum; and

the transmitter is operable to transmit the data according to the digital broadcast format via the at least one identified channel of the digital broadcast television spectrum.

25 . The communication system of claim 21 , wherein the digital broadcast format comprises an ATSC (Advanced Television Systems Committee) format, a T-DMB (Terrestrial Digital Multimedia Broadcasting) format, a DVB (Digital Video Broadcasting) format, an Integrated Services Digital Broadcasting Terrestrial (ISDB-T) format, or a Moving Picture Experts Group Transport Stream (MPEG-TS) format.

26 . The communication system of claim 21 , wherein the channel identifier is operable to identify the at least one channel at least by identifying television band white space.

27 . The communication system of claim 21 , wherein the data comprises at least one of audio data, video data, text data, speech data, graphics data, and ancillary interactivity data.

28 . The communication system of claim 21 , wherein the data receiver/feedback unit is operable to compare at least the portion of the received representation of the data to at least the portion of the transmitted data at least by comparing one or more samples of the received representation of the data to corresponding one or more samples of the transmitted data.

29 . The communication system of claim 21 , wherein the one or more processors are operable to determine whether to adjust the broadcast transmission parameter or the data transformation parameter at least by determining whether to adjust a transmit power used for subsequent data transmission.

30 . The communication system of claim 29 , wherein the one or more processors are configured to determine whether to adjust the transmit power at least by determining whether any differences between at least the portion of the received representation of the data and at least the portion of the transmitted data exceed a defined threshold indicative of signal distortion, and wherein the transmitter is further operable to transmit additional data via the at least one identified channel with increased power when the differences exceed the defined threshold.

31 . The communication system of claim 30 , wherein:

the data receiver/feedback unit is further operable to receive a representation of additional data and compare at least a portion of the representation of the additional data to at least a portion of the transmitted additional data;

responsive to determining that any differences between at least the portion of the received representation of the additional data and at least the portion of the transmitted additional data continue to exceed the defined threshold, the channel identifier is further operable to identify at least one other channel currently available in the digital broadcast spectrum; and

the transmitter is further operable to transmit further data via the at least one other identified channel.

32 . The communication system of claim 31 , wherein the one or more processors are further configured to repeat the transmitting of additional data with increased power multiple iterations prior to transmitting further data via the at least one other identified channel.

33 . The communication system of claim 30 , wherein the one or more processors are configured to determine whether any differences between at least the portion of the received representation of the data and at least the portion of the transmitted data exceed the defined threshold at least by determining that a defined number of data packets included in at least the portion of the transmitted data are not included in at least the portion of the received representation of the data.

34 . The communication system of claim 21 , wherein:

the transmitter is operable to transmit the data at least by inserting a plurality of audio watermarks into the data prior to transmission;

the data receiver/feedback unit is operable to receive the representation of the data at least by receiving representations of the audio watermarks; and

the data receiver/feedback unit is operable to compare the received representations of the audio watermarks to the audio watermarks contained in the transmitted data.

35 . The communication system of claim 34 , wherein the audio watermarks comprises at least one of a pseudo-noise spread-spectrum sequence and inaudible audio.

36 . The communication system of claim 34 , wherein the one or more processors are configured to determine whether to adjust the broadcast transmission parameter or the data transformation parameter at least by determining whether to adjust a transmit power used for subsequent data transmission based upon whether any differences between the received representations of the audio watermarks to the audio watermarks contained in the transmitted data exceed a defined threshold.

37 . The communication system of claim 34 , wherein the data receiver/feedback unit is operable to compare the received representations of the audio watermarks to the audio watermarks contained in the transmitted data at least by identifying locations of the representations of the audio watermarks within the received representation of the data, and by determining at least the portion of the received representation of the data that is to be compared to at least the portion of the transmitted data based upon the identified locations.

38 . The communication system of claim 21 , wherein the one or more processors are further configured to estimate an expected amount of signal distortion in the received representation of the data and to account for the expected amount of signal distortion in the received representation of the data.

39 . The communication system of claim 21 , wherein the data receiver/feedback unit is operable to compare at least the portion of the received representation of the data to at least the portion of the transmitted data at least by comparing at least the portion of the received representation of the data to at least the portion of the transmitted data to estimate at least one of a signal round-trip propagation delay, one or more multipath characteristics, a loudness value, and one or more room equalization characteristics.

40 . The communication system of claim 21 , wherein the transmitted data is part of at least one multimedia data stream, and wherein the representation of the data includes a representation of only a subset of data included within the at least one multimedia data stream.

41 . The communication system of claim 21 , wherein the communication system comprises a wireless communication device handset.

42 . The communication system of claim 21 , wherein the communication system comprises one or more integrated circuit devices.

43 . A communication system, comprising:

means for identifying at least one channel currently available in a digital broadcast spectrum;

means for transmitting data via the at least one identified channel of the digital broadcast spectrum, wherein the transmitted data complies with a digital broadcast format;

means for receiving a representation of the data;

means for comparing at least a portion of the received representation of the data to at least a portion of the transmitted data; and

means for determining whether to adjust a broadcast transmission parameter or a data transformation parameter for use in subsequent data communication based upon the comparison.

44 . The communication system of claim 43 , further comprising:

means for transforming the data into the digital broadcast format; and

means for modulating the transformed data prior to its transmission.

45 . The communication system of claim 44 , wherein the means for determining whether to adjust the broadcast transmission parameter or the data transformation parameter comprises means for determining whether to adjust a coding parameter for use in subsequent data transformation operations.

46 . The communication system of claim 43 , wherein the means for comparing at least the portion of the received representation of the data to at least the portion of the transmitted data comprises means for comparing one or more samples of the received representation of the data to corresponding one or more samples of the transmitted data.

47 . The communication system of claim 43 , wherein the means for determining whether to adjust the broadcast transmission parameter or the data transformation parameter comprises means for determining whether to adjust a transmit power used for subsequent data transmission.

48 . The communication system of claim 47 , wherein the means for determining whether to adjust the transmit power comprises means for determining whether any differences between at least the portion of the received representation of the data and at least the portion of the transmitted data exceed a defined threshold indicative of signal distortion, and wherein the communication system further comprises:

means for transmitting additional data via the at least one identified channel with increased power when the differences exceed the defined threshold.

49 . The communication system of claim 48 , further comprising:

means for receiving a representation of additional data;

means for comparing at least a portion of the representation of the additional data to at least a portion of the transmitted additional data;

means for responsive to determining that any differences between at least the portion of the received representation of the additional data and at least the portion of the transmitted additional data continue to exceed the defined threshold, identifying at least one other channel currently available in the digital broadcast spectrum; and

means for transmitting further data via the at least one other identified channel.

50 . The communication system of claim 43 , wherein:

the means for transmitting the data comprises means for inserting a plurality of audio watermarks into the data prior to transmission;

the means for receiving the representation of the data comprises means for receiving representations of the audio watermarks; and

the means for comparing comprises means for comparing the received representations of the audio watermarks to the audio watermarks contained in the transmitted data.

51 . The communication system of claim 50 , wherein the audio watermarks comprises at least one of a pseudo-noise spread-spectrum sequence and inaudible audio.

52 . The communication system of claim 50 , wherein the means for determining whether to adjust the broadcast transmission parameter or the data transformation parameter comprises means for determining whether to adjust a transmit power used for subsequent data transmission based upon whether any differences between the received representations of the audio watermarks to the audio watermarks contained in the transmitted data exceed a defined threshold.

53 . The communication system of claim 50 , wherein the means for comparing the received representations of the audio watermarks to the audio watermarks contained in the transmitted data comprises:

means for identifying locations of the representations of the audio watermarks within the received representation of the data; and

means for determining at least the portion of the received representation of the data that is to be compared to at least the portion of the transmitted data based upon the identified locations.

54 . The communication system of claim 43 , further comprising:

means for estimating an expected amount of signal distortion in the received representation of the data, and wherein the comparing comprises accounting for the expected amount of signal distortion in the received representation of the data.

55 . The communication system of claim 43 , wherein the means for comparing at least the portion of the received representation of the data to at least the portion of the transmitted data comprises means for comparing at least the portion of the received representation of the data to at least the portion of the transmitted data to estimate at least one of a signal round-trip propagation delay, one or more multipath characteristics, a loudness value, and one or more room equalization characteristics.

56 . A computer-readable storage medium encoded with instructions for causing one or more processors to:

identify at least one channel currently available in a digital broadcast spectrum;

transmit data via the at least one identified channel of the digital broadcast spectrum, wherein the transmitted data complies with a digital broadcast format;

receive a representation of the data;

compare at least a portion of the received representation of the data to at least a portion of the transmitted data; and

determine whether to adjust a broadcast transmission parameter or a data transformation parameter for use in subsequent data communication based upon the comparison.

57 . The computer-readable storage medium of claim 56 , further encoded with instructions to:

transform the data into the digital broadcast format; and

modulate the transformed data prior to its transmission.

58 . The computer-readable storage medium of claim 57 , wherein the instructions to determine whether to adjust the broadcast transmission parameter or the data transformation parameter comprise instructions to determine whether to adjust a coding parameter for use in subsequent data transformation operations.

59 . The computer-readable storage medium of claim 56 , wherein the instructions to compare at least the portion of the received representation of the data to at least the portion of the transmitted data comprise instructions to compare one or more samples of the received representation of the data to corresponding one or more samples of the transmitted data.

60 . The computer-readable storage medium of claim 56 , wherein the instructions to determine whether to adjust the broadcast transmission parameter or the data transformation parameter comprise instructions to determine whether to adjust a transmit power used for subsequent data transmission.

61 . The computer-readable storage medium of claim 60 , wherein the instructions to determine whether to adjust the transmit power comprise instructions to determine whether any differences between at least the portion of the received representation of the data and at least the portion of the transmitted data exceed a defined threshold indicative of signal distortion, and wherein the computer-readable storage medium is further encoded with instructions to:

transmit additional data via the at least one identified channel with increased power when the differences exceed the defined threshold.

62 . The computer-readable storage medium of claim 61 , further encoded with instructions to:

receive a representation of additional data;

compare at least a portion of the representation of the additional data to at least a portion of the transmitted additional data;

responsive to determining that any differences between at least the portion of the received representation of the additional data and at least the portion of the transmitted additional data continue to exceed the defined threshold, identify at least one other channel currently available in the digital broadcast spectrum; and

transmit further data via the at least one other identified channel.

63 . The computer-readable storage medium of claim 56 , wherein:

the instructions to transmit the data comprise instructions to insert a plurality of audio watermarks into the data prior to transmission;

the instructions to receive the representation of the data comprise instructions to receive representations of the audio watermarks; and

the instructions to compare comprise instructions to compare the received representations of the audio watermarks to the audio watermarks contained in the transmitted data.

64 . The computer-readable storage medium of claim 63 , wherein the audio watermarks comprises at least one of a pseudo-noise spread-spectrum sequence and inaudible audio.

65 . The computer-readable storage medium of claim 63 , wherein the instructions to determine whether to adjust the broadcast transmission parameter or the data transformation parameter comprise instructions to determine whether to adjust a transmit power used for subsequent data transmission based upon whether any differences between the received representations of the audio watermarks to the audio watermarks contained in the transmitted data exceed a defined threshold.

66 . The computer-readable storage medium of claim 63 , wherein the instructions to compare the received representations of the audio watermarks to the audio watermarks contained in the transmitted data comprise instructions to:

identify locations of the representations of the audio watermarks within the received representation of the data; and

determine at least the portion of the received representation of the data that is to be compared to at least the portion of the transmitted data based upon the identified locations.

67 . The computer-readable storage medium of claim 56 , further encoded with instructions to:

estimate an expected amount of signal distortion in the received representation of the data, and wherein the comparing comprises accounting for the expected amount of signal distortion in the received representation of the data.

68 . The computer-readable storage medium of claim 56 , wherein the instructions to compare at least the portion of the received representation of the data to at least the portion of the transmitted data comprise instructions to compare at least the portion of the received representation of the data to at least the portion of the transmitted data to estimate at least one of a signal round-trip propagation delay, one or more multipath characteristics, a loudness value, and one or more room equalization characteristics.