Packet configuring method and packet receiver
First Claim
1. A method of configuring packets, said packets each including a training portion and a data portion, the method comprising 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 a phase difference between two neighboring sequences of said K sequences is used for frequency-offset estimation, wherein an auto-correlation function for said sequence of N symbols is in an impulse state.
0 Assignments
0 Petitions
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 intersymbol 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.
5 Citations
16 Claims
-
1. A method of configuring packets, said packets each including a training portion and a data portion, the method comprising 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 a phase difference between two neighboring sequences of said K sequences is used for frequency-offset estimation, wherein an auto-correlation function for said sequence of N symbols is in an impulse state.
-
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 1 or more), the packet receiver comprising comprises:
-
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 (4, 13)
-
-
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 1 or more), said packet receiver comprising comprises:
-
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 (3, 5, 14)
-
-
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 1 or more), said method comprising comprises:
-
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 (7, 8, 15)
-
-
12. A method of configuring packets, said packets each including a training portion and a data portion, the method comprising 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 a phase difference between two neighboring sequences of said K sequences is used for frequency-offset estimation.
- 16. A packet transmitter that transmits packets, 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), wherein a phase difference between two neighboring sequences of said K sequences is used for frequency-offset estimation, each of said K sequences being formed of N symbols (where N is an integer of 1 or more).
Specification