Packet configuring method and packet receiver
First Claim
1. A method of configuring packets packet transmission in a transmitter, said packets each including a training portion and a data portion, the method comprising:
- said transmitter forming said training portion by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbols (where N is an integer of 2 1 or more), wherein at least two neighboring sequences of said K sequences are used for frequency-offset estimation, wherein an auto-correlation function for said sequence of N symbols is in an impulse state; and
said transmitter transmitting said packets.
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Accused Products
Abstract
A packet receiver is provided that accurately estimates a frequency offset and a channel impulse response even when a transmitted packet is detected with an erroneous timing in a communication mode (typified by the LAN (local Area Network)) where packets are asynchronously transmitted, and thus provides a training sequence which can demodulate the received packet. The training sequence 101 is formed of K sequences 100-1 to 100-K serially connected, each formed of the same N symbols. Even in a channel where a inter-symbol interference occurs when such a training sequence is used, a received signal shifted by the time corresponding to N-symbols becomes the signal which is different by a phase difference caused by a frequency offset between the transmitter and the receiver. Thus, even if the head of a packet is detected with an erroneous timing, the frequency offset can be estimated.
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Citations
22 Claims
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1. A method of configuring packets packet transmission in a transmitter, said packets each including a training portion and a data portion, the method comprising:
- said transmitter forming said training portion by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbols (where N is an integer of 2 1 or more), wherein at least two neighboring sequences of said K sequences are used for frequency-offset estimation, wherein an auto-correlation function for said sequence of N symbols is in an impulse state; and
said transmitter transmitting said packets. - View Dependent Claims (17)
- said transmitter forming said training portion by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbols (where N is an integer of 2 1 or more), wherein at least two neighboring sequences of said K sequences are used for frequency-offset estimation, wherein an auto-correlation function for said sequence of N symbols is in an impulse state; and
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2. A packet receiver that receives packets, each packet including a training portion and a data portion used to initialize said packet receiver, said training portion being formed by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbols (where N is an integer of 2 or more), the packet receiver comprising:
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a frequency-offset estimation means for estimating a frequency offset based on a phase difference between two neighboring sequences of K sequences of a received packet, each of said K sequences being formed of N symbols; a frequency-offset compensation means for compensating a frequency offset contained in said received packet based on said frequency offset estimation; and a channel impulse response estimation means for estimating an impulse response of a channel based on an output for which the frequency offset is compensated. - View Dependent Claims (3, 4, 5)
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6. A packet receiver for receiving packets, each of said packets including a training portion and a data portion used to initially set a receiver, said training portion being formed by serially connecting K sequences (where K is an integer of 2 or more), each of K sequences being formed of N symbols (where N is an integer of 2 or more), said packet receiver comprising:
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a frequency offset estimation means for detecting a phase difference between a sequence received prior to NT (where T is a continuous time of one symbol) and a currently received sequence, and for estimating a frequency offset based on said phase difference; a frequency offset compensation means for compensating said frequency offset by rotating the phase of a received signal in the frequency offset compensation direction based on a frequency offset estimation value; and a channel impulse estimation means for estimating an impulse response of a channel based on an output from an output for which the frequency offset is compensated. - View Dependent Claims (7, 8)
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9. A packet receiving method for receiving packets, each of said packets including a training portion and a data portion to initially set a receiver, said training portion being formed by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbols (where N is an integer of 2 or more), said method comprising:
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estimating a frequency offset based on a phase difference between two neighboring sequences of K sequences of a received packet, each of K sequences being formed of N symbols; compensating a frequency offset contained in said received packet based on a frequency offset estimation value; and estimating an impulse response of a channel based on a received packet of which the frequency offset is compensated. - View Dependent Claims (10, 11)
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12. A method of packet transmission in a transmitter, said packets each including a training portion and a data portion, the method comprising:
- said transmitter forming said training portion by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbol(s) (where N is an integer of 1 or more), wherein at least two neighboring sequences of said K sequences are used for frequency-offset estimation; and
said transmitter transmitting said packets. - View Dependent Claims (18)
- said transmitter forming said training portion by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbol(s) (where N is an integer of 1 or more), wherein at least two neighboring sequences of said K sequences are used for frequency-offset estimation; and
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13. A packet transmitter comprising:
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a packet configuring unit, each packet including a training portion and a data portion, that forms said training portion by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbols (where N is an integer of 1 or more), wherein at least two neighboring sequences of said K sequences are used for frequency-offset estimation; and a transmitting unit that transmits each said packet. - View Dependent Claims (19)
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14. A packet receiver comprising:
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a receiving unit that receives a packet; a packet estimating unit, each packet including a training portion and a data portion, said training portion being formed by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbols (where N is an integer of 1 or more), said packet estimating unit estimating frequency offset by using at least two neighboring sequences of said K sequences. - View Dependent Claims (20)
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15. A method of receiving a packet with a packet receiver, the method comprising:
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the packet receiver receiving a packet; the packet receiver estimating the packet, each packet including a training portion and a data portion and formed that said training portion by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbols (where N is an integer of 1 or more), the estimating step estimating frequency offset by using at least two neighboring sequences of said K sequences. - View Dependent Claims (21)
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16. A communication system comprising:
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a packet transmitter; a packet receiver; wherein said packet receiver comprises; a receiving unit that receives a packet; a packet estimating unit, each packet including a training portion and a data portion, said training portion being formed by serially connecting K sequences (where K is an integer of 2 or more), each of said K sequences being formed of N symbols (where N is an integer of 1 or more), said packet estimating unit estimating frequency offset by using at least two neighboring sequences of said K sequences. - View Dependent Claims (22)
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Specification