Synchronization method and apparatus and location awareness method and apparatus in chaotic communication system

A synchronization method comprising:

• receiving, at a first device, a packet from a second device;
• transmitting a time counter value from the first device to the second device, wherein the time counter value is determined when the first device receives the packet;
• receiving, at the first device, an offset from the second device, wherein the offset is determined by comparing the device time counter value with a time when the second device should receive the device time counter value according to a distance between the first device and the second device, and the distance is determined based on a time when the second device transmits the packet to the device and a time when the second device receives the device time counter value from the first device;
• and
• adjusting the device time counter value of the first device based on the offset.

A location awareness method in a chaotic communication system, comprising:

• receiving a data frame which includes a template chaotic signal to be determined to be arranged at a predetermined position of the data frame allocated to a user, and a data source signal obtained by modulating the template chaotic signal;
• detecting a position of the data frame in which the template chaotic signal is substantially arranged;
• and
• determining a distance between a device transmitting the data frame and a device receiving the data frame based on a difference between the position of the data frame in which the template chaotic signal is substantially arranged and the predetermined position.

A synchronization apparatus in a chaotic communication system, the synchronization apparatus comprising:

• a distance calculator which determines the distance between the synchronization apparatus and a device, using a time when a first packet is transmitted to the device and a time when a second packet containing a device time counter value in response to the first packet is received from the device;
• an offset calculator which determines an offset by comparing the time counter value with a time when the device should receive the packet containing the device time counter value according to the distance;
• and
• an offset transmitting unit which provides the offset to the device so that the device adjusts the time counter value based on the offset.

A synchronization apparatus of a device in a chaotic communication system, the synchronization apparatus comprising:

• a packet transmitting unit which transmits a second packet containing a device time counter value determined when the device receives a first packet from another device;
• and
• an offset adjusting unit which receives an offset from the other device and adjusts the device time counter value based on the offset,
• wherein a distance is determined based on a time when the other device transmits the first packet to the device and a time when the other device receives the second packet containing the device time counter value from the device, and
• the offset is determined by comparing the device time counter value and a time when the other device should receive the second packet containing the device time counter value according to the distance.