Velocity enhancement for OFDM Systems
First Claim
1. An orthogonal frequency division multiplexing (OFDM) transmitter method, comprising:
- arranging OFDM data symbols representing data bits for transmission in a packet;
removing at least one data symbol and replacing the removed data symbol with a pilot symbol; and
transmitting the packet.
4 Assignments
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Accused Products
Abstract
An orthogonal frequency division multiplexing (OFDM) transmitter method, consistent with certain embodiments of the present invention arranges OFDM data symbols representing data bits for transmission in a packet. A prescribed pattern of OFDM data symbols are removed (212) and replaced (216) with pilot symbols. The packet is then transmitted (220) to an OFDM receiver that receives the packet (224) and determines a channel correction factor from the pilot pattern. The receiver then estimates a plurality of channel correction factors, one for each of the plurality of OFDM symbols representing data (228) and uses these correction factors to correct the OFDM symbols representing data (232). Arbitrary data are then inserted in place of the pilot symbols (236). The OFDM symbols representing data along with the arbitrary data are then decoded using an error correction decoder that corrects the errors induced by substitution of the pilot symbols for data symbols (240).
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Citations
59 Claims
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1. An orthogonal frequency division multiplexing (OFDM) transmitter method, comprising:
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arranging OFDM data symbols representing data bits for transmission in a packet;
removing at least one data symbol and replacing the removed data symbol with a pilot symbol; and
transmitting the packet. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An orthogonal frequency division multiplexing (OFDM) receiver method, comprising:
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receiving a packet containing a plurality of OFDM symbols representing data, wherein at least one of the OFDM data symbols has been replaced with a pilot pattern;
determining a channel correction factor from the pilot pattern;
estimating a plurality of channel correction factors, one for each of the plurality of OFDM symbols representing data;
correcting the OFDM symbols representing data using the plurality of channel correction factors; and
decoding the OFDM symbols representing data using an error correction decoder. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. An orthogonal frequency division multiplexing (OFDM) transmitter, comprising:
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a binary to complex symbol mapper that maps a binary input representing a packet of information to a stream of constellation symbols;
a serial to parallel converter that converts the stream of constellation symbols to a parallel collection of data symbols;
a pilot substitutor that removes at least one data symbol and replaces the removed data symbol with a pilot symbol; and
an inverse Fast Fourier Transformer (FFT) that receives the collection of data symbols and the pilot symbol as inputs and produces an OFDM output signal. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. An orthogonal frequency division multiplexing (OFDM) receiver, comprising:
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an OFDM receiver that receives a packet containing a plurality of OFDM symbols representing data, wherein at least one of the OFDM data symbols has been replaced with a pilot pattern;
a Fast Fourier Transformer receiving the OFDM symbols;
a channel estimator that estimates a channel correction factor from the pilot pattern and estimates a plurality of channel correction factors, one for each of the plurality of OFDM symbols representing data;
a channel corrector that corrects the OFDM symbols representing data using the plurality of channel correction factors; and
a decoder that decodes the OFDM symbols representing data using an error correction decoder. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37)
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38. An orthogonal frequency division multiplexing (OFDM) communication method, comprising:
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at an OFDM transmitter, establishing a pattern of pilot symbols to substitute for data symbols in a transmitted OFDM data packet;
identifying the pattern of pilot symbols by a code; and
transmitting the code to an OFDM receiver. - View Dependent Claims (39, 40, 41)
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42. An orthogonal frequency division multiplexing (OFDM) communication method, comprising:
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at an OFDM receiver, receiving a code that identifies a pattern of pilot symbols substituted for data symbols in a transmitted OFDM data packet;
translating the code to the pattern of pilot symbols;
substituting arbitrary data symbols for the pilot symbols; and
decoding the data symbols. - View Dependent Claims (43, 44, 45)
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46. An orthogonal frequency division multiplexing (OFDM) carrier wave, comprising:
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a plurality of OFDM data symbols;
a pattern of pilot symbols substituted for data symbols; and
a segment of code identifying the pattern of pilot symbols. - View Dependent Claims (47, 48, 49, 50)
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51. A transmitter method, comprising:
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arranging data symbols representing data bits for transmission in a packet;
removing at least one data symbol and replacing the removed data symbol with a pilot symbol and thus introducing the likelihood of a data error; and
transmitting the packet. - View Dependent Claims (52, 53, 54)
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55. A receiver method, comprising:
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receiving a packet containing a plurality of symbols representing data, wherein at least one of the data symbols has been replaced with a pilot pattern;
determining a channel correction factor from the pilot pattern;
estimating a plurality of channel correction factors;
correcting the symbols representing data using the plurality of channel correction factors; and
decoding the symbols representing data using an error correction decoder. - View Dependent Claims (56, 57, 58, 59)
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Specification