Use of Pilot Symbols for Data Transmission in Uncompressed, Wireless Transmission of Video
First Claim
1. Apparatus for wireless transmission, comprising:
- means for receiving uncompressed video signal components;
means for performing a de-correlating transform on said uncompressed video signal components to provide transform coefficients;
means for removing a portion of said transform coefficients;
means for separating remaining transform coefficients into a first group comprising low frequency coefficients and a second group comprising high frequency coefficients; and
means for mapping each of said remaining coefficients to a transmission symbol, said means for mapping further comprising means for separating said coefficients of said first group into a first value comprising most-significant bits of said coefficients and for mapping said most-significant bits to one of a plurality of constellation points of a transmission symbol, and into a second value comprising least-significant bits of said coefficients;
said transmission symbol carrying said first value further comprising a pilot symbol.
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Accused Products
Abstract
The uncompressed wireless transmission of video, as with many other wireless applications, requires constant knowledge of channel characteristics at the receiver end. To estimate the channel and track its changes, pilots containing known data are sent in various parts of the used bandwidth. The use of such pilots reduces the effective bandwidth available for data transmission. Due to the relative high immunity to introduced interference of certain transmission modes, such as QPSK and QAM, pilots can be modulated by digital data components. At the receiver, pilots are demodulated and used for a decision-directed circuit to determine the characteristics of the transmission channel. The additional bandwidth allows a higher data rate which may be such used for various purposes as diversity, coding, etc. Such use of pilot signals is of particular advantage in the wireless transmission of the DC and near DC components of essentially uncompressed video.
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Citations
19 Claims
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1. Apparatus for wireless transmission, comprising:
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means for receiving uncompressed video signal components;
means for performing a de-correlating transform on said uncompressed video signal components to provide transform coefficients;
means for removing a portion of said transform coefficients;
means for separating remaining transform coefficients into a first group comprising low frequency coefficients and a second group comprising high frequency coefficients; and
means for mapping each of said remaining coefficients to a transmission symbol, said means for mapping further comprising means for separating said coefficients of said first group into a first value comprising most-significant bits of said coefficients and for mapping said most-significant bits to one of a plurality of constellation points of a transmission symbol, and into a second value comprising least-significant bits of said coefficients;
said transmission symbol carrying said first value further comprising a pilot symbol. - View Dependent Claims (2, 3, 4, 5)
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6. A wireless communication system, comprising:
a transmitter comprising;
an input for receiving uncompressed components of a high definition video signal;
means for performing a de-correlating transform on said uncompressed components to produce transform coefficients;
means for removing a portion of said transform coefficients; and
means for mapping each of said remaining coefficients to a transmission symbol and for mapping at least a portion of said coefficients to a pilot symbol having a dual-function. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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13. A communication method, comprising the steps of:
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converting digital data to transmission symbols;
generating a sequence of pilot symbols;
placing said pilot symbols in predefined positions between said transmission symbols to produce an output stream of symbols, wherein at least one of said pilot symbols is a dual-function symbol that carries a portion of said digital data; and
transmitting the plurality of output stream of symbols over a wireless communication link. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification