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US 6,487,252 B1Granted
Wireless communication system and method for synchronization
AssigneeMotorola, Inc.
InventorsJohn Eric Kleider, Michael Eugene Humphrey, Jeffery Scott Chuprun, Chad Scott Bergstrom, Byron L. Tarver
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Abstract
An orthogonal frequency division multiplexed wideband communication system provides improved time and frequency synchronization by inserting an unevenly spaced pilot sequence within the constellation data. A receive correlates the received data using the unevenly spaced pilot sequence. The pilot sequence is generated with a maximum length pseudo random noise code and inserted into frequency bins having prime numbers.
Claims19
A wireless communication system comprising:
- a transmitter and a receiver coupled by an communication link, the transmitter comprising:
- a modulator element for converting digital data to symbols, said symbols being assigned to frequency bins of a set of frequency bins;
- a pilot tone generator for generating a sequence of pilot tones, each pilot tone being associated with frequency bins not assigned to symbols from said modulator element, the frequency bins assigned to said pilot tones being unevenly spaced therebetween;
- a polyphase filter for performing an inverse fast Fourier transform (FFT) on the symbols assigned to said set frequency bins and providing a plurality of output samples;
- a transmitting portion for transmitting the plurality of output samples over the communication link;
- the receiver comprises a correlator for correlating the plurality of output samples received over the communication link with a reference for use in retrieving said digital data, said reference comprising said sequence of pilot tones associated with the unassigned frequency bins;
- and
- the pilot tone generator includes a pilot tone location assignment table identifying said frequency bins assigned to each pilot tone.
5 more elements
A method of communicating comprising the steps of:
- converting digital data to symbols, said symbols being assigned to frequency bins of a set of frequency bins;
- generating a sequence of pilot tones, each pilot tone being associated with frequency bins not assigned to symbols from said modulator element, the frequency bins assigned to said pilot tones being unevenly spaced therebetween;
- performing an inverse fast Fourier transfer (FFT) on the symbols assigned to said set frequency bins and providing a plurality of output samples;
- and
- transmitting the plurality of output samples over a communication link;
- correlating the plurality of output samples received over the communication link with a reference for use in retrieving said digital data, said reference comprising said sequence of pilot tones associated with unassigned frequency bins;
- and
- the generating step includes the step of reading a pilot tone location assignment table identifying said frequency bins assigned to each pilot tone.
5 more elements
Dependencies are inferred from the claim text.