TRANSMITTER, TRANSMISSION METHOD, AND NON-TRANSITORY COMPUTER-READABLE MEDIUM STORING PROGRAM

• US 20140307728A1
• Filed: 08/01/2012
• Published: 10/16/2014
• Est. Priority Date: 11/09/2011
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Nakajima, Hiroaki
• Granted Patent: US 9,379,833 B2
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: G04R 20/14 the radio signal being a telecommunication standard signal, e.g. GSM
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04W 56/003 Arrangements to increase tolerance to errors in transmission or reception timing
• CPC Class Codes: H04W 56/0055 determining timing error of reception due to propagation delay

Abstract

A transmitter is connected to a master device, and wirelessly transmits a timing packet, which is transmitted from the master device, to a receiver. The transmitter includes: an input unit for receiving an input of a timing packet from the master device; a delay compensation unit for obtaining a packet length of the timing packet and a modulation system used for radio transmission, calculating a device-specific delay value and a first propagation delay value based on the modulation system and the packet length, and calculating a delay compensation value based on the device-specific delay value and the first propagation delay value; a filter unit for adding the delay compensation value to a specific field of the timing packet; and an output unit for outputting the timing packet to the receiver.

Claims

1. A transmitter comprising:

a input unit that receives an input of a timing packet from a master device;

a delay compensation unit that obtains a packet length of the timing packet and a modulation system used for radio transmission, calculating a device-specific delay value and a first propagation delay value based on the modulation system and the packet length, and calculating a delay compensation value based on the device-specific delay value and the first propagation delay value;

a filter unit that adds the delay compensation value to a specific field of the timing packet; and

a output unit that wirelessly transmits the timing packet to a receiver.

2. The transmitter according to claim 1, wherein the delay compensation unit further obtains a transmission distance to the receiver, calculates a second propagation delay value based on the transmission distance, and calculates the delay compensation value based on the device-specific delay value, the first propagation delay value, and the second propagation delay value.

3. The transmitter according to claim 1, further comprising a radio delay measurement unit that detects a phase difference between a transmission frame pulse wirelessly transmitted to the receiver by the transmitter and a reception frame pulse wirelessly transmitted by the receiver and received by the transmitter, and calculating a third propagation delay value based on the phase difference,

wherein the delay compensation unit calculates the delay compensation value based on the device-specific delay value and the third propagation delay value.

4. The transmitter according to claim 1, further comprising a radio framer unit that determines a modulation system in the radio transmission based on a result of the radio transmission between the transmitter and the receiver, and notifying the delay compensation means of the modulation system.

5. The transmitter according to claim 4, further comprising a radio deframer unit that receives a reception state signal of the radio transmission from the receiver,

wherein the radio framer unit determines a modulation system in the radio transmission based on the reception state signal.

6. A transmission method comprising:

a calculation step of calculating a device-specific delay value and a first propagation delay value based on a packet length of a timing packet and a modulation system used for radio transmission, and calculating a delay compensation value based on the device-specific delay value and the first propagation delay value;

an addition step of adding the delay compensation value to a specific field of the timing packet; and

an output step of wirelessly transmitting the timing packet to a receiver.

7. The transmission method according to claim 6, wherein the calculation step further includes:

calculating a second propagation delay value based on a transmission distance to the receiver; and

calculating the delay compensation value based on the device-specific delay value, the first propagation delay value, and the second propagation delay value.

8. The transmission method according to claim 6, wherein the calculation step further includes:

calculating a third propagation delay value based on a phase difference between a transmission frame pulse wirelessly transmitted to the receiver by the transmitter and a reception frame pulse wirelessly transmitted by the receiver and received by the transmitter; and

calculating the delay compensation value based on the device-specific delay value and the third propagation delay value.

9. A non-transitory computer-readable medium storing a program for causing a computer to execute:

calculating a device-specific delay value and a first propagation delay value based on a packet length of a timing packet and a modulation system used for radio transmission, and calculating a delay compensation value based on the device-specific delay value and the first propagation delay value;

adding the delay compensation value to a specific field of the timing packet; and

wirelessly transmitting the timing packet to a receiver.