CIRCUIT, SYSTEM AND METHOD FOR COMMUNICATION BETWEEN TWO NODES OF A RADIO NETWORK

• US 20100165866A1
• Filed: 12/29/2009
• Published: 07/01/2010
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Sachse, Eric, Kluge, Wolfram, Ferchland, Tilo
• Granted Patent: US 8,406,144 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: G01S 13/84 for distance determination by phase measurement
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

A circuit, system, and method for range finding between two nodes of a radio network, in particular in conformance with the industry standard IEEE 802.15.4. A mode for finding the range to a second node is initiated by the first node. A command for range finding with the address of the second node is transmitted from the first node to the second node in the mode for range finding. The second node is switched into the range finding mode by the command. A sequence is controlled by the command in the range finding mode. As a result of the control by the command, a first signal is transmitted by the first node in a transmission time window of the sequence and the first signal is received by the second node in an associated reception time window of the sequence, and a first phase value of the first signal is measured. As a result of the control by the command, a second signal is transmitted by the second node in a transmission time window of the sequence and the second signal is received by the first node in an associated reception time window of the sequence, and a second phase value of the second signal is measured. As a result of the control by the command, the first frequency of the first signal is changed by a frequency difference and the second frequency of the second signal is changed by the frequency difference in a subsequent time window of the sequence.

Claims

1. A method for communication between two nodes of a radio network, the method comprising:

initiating a mode for finding a range to a second node by the first node;

transmitting a command for range finding with an address of the second node from the first node to the second node in the mode for range finding;

switching the second node into the range finding mode by the command;

controlling a sequence by the command in the range finding mode;

transmitting, as a result of the control by the command, a first signal by the first node in a transmission time window of the sequence, the first signal being received by the second node in an associated reception time window of the sequence;

measuring a first phase value of the first signal;

transmitting, as a result of the control by the command, a second signal by the second node in the transmission time window of the sequence, the second signal being received by the first node in an associated reception time window of the sequence;

measuring a second phase value of the second signal; and

changing, as a result of the control by the command, the first frequency of the first signal by a frequency difference and changing the second frequency of the second signal by the frequency difference in a subsequent time window of the sequence.

2. The method according to claim 1, wherein the transmission time windows and reception time windows are repeated after the time window for changing the first frequency of the first signal and the second frequency of the second signal, and wherein a third phase value of the first signal and a fourth phase value of the second signal are measured.

3. The method according to claim 1, wherein the transmission time windows and reception time windows and the time window for changing the first frequency of the first signal and the second frequency of the second signal are repeated for a plurality of different first frequencies and a plurality of different second frequencies.

4. The method according to claim 1, wherein a sequence of the first and/or second frequency for range finding is transmitted to the second node with the range finding command.

5. The method according to claim 1, wherein a frame for synchronizing a start time of the sequence with the transmission time windows and reception time windows and the time window for changing the first frequency and the second frequency is transmitted from the second node to the first node under control of the command.

6. The method according to claim 1, wherein an indicator to flag following payload data of a frame to be decoded contained in a frame is changed by the first node to a value associated with range finding under the control of the command, and wherein the second node transmits a frame or a synchronization frame with an altered value of the indicator in the range finding mode to the first node.

7. The method according to claim 1, wherein a time synchronization of the transmission time windows and reception time windows of the sequence in the first node and the node takes place as a result of the control by the command.

8. The method according to claim 1, wherein a first timer is started by the first node as a function of a reception time of a frame for synchronization, wherein a second timer is started by the second node as a function of a transmission time of the frame for synchronization, and wherein the sequence is started in both nodes in a synchronized manner by the first node upon expiration of the first timer and by the second node upon expiration of the second timer.

9. The method according to claim 1, wherein measurement results of the range finding are transmitted from the second node to the first node with a reset value of the indicator.

10. The method according to claim 9, wherein the altered value of the indicator is transmitted to the second node with the range finding command.

11. The method according to claim 1, wherein the range finding command is transmitted in a secured manner, in particular encrypted.

12. A circuit of a node of a radio network, the circuit being configured for address-dependent reception of a range finding command and is switchable into a range finding mode by the command, wherein the circuit is configured to control a sequence through the command, wherein the circuit is configured to transmit a first signal in a transmission time window of the sequence, wherein the circuit is configured to receive a second signal in a transmission time window of the sequence and to measure a first phase value of the second signal, wherein the circuit is configured to change the first frequency of the first signal by a frequency difference in a time window of the sequence following the reception time window, and wherein the circuit is configured to change a reception frequency for reception of the second signal with altered second frequency for a subsequent reception time window of the sequence.

13. Radio network system, comprising:

a first node; and

a second node,

wherein the first node is configured for initiating a mode for measurement of a distance to the second node,

wherein the first node is configured for transmitting to the second node a range finding command with an address of the second node,

wherein the second node is switchable into the range finding mode by the command,

wherein, in the range finding mode, the first node A and the second node are configured to control a sequence by the command,

wherein the first node is configured to transmit, under control by the command, a first signal in a transmission time window of the sequence and the second node is configured to receive, under control by the command, the first signal and to measure a first phase value of the first signal in an associated reception time window of the sequence,

wherein the second node is configured to transmit, under control by the command, the second signal in a transmission time window of the sequence, and the first node is configured to receive, under control by the command, the second signal and to measure a second phase value of the second signal in an associated reception time window of the sequence, and

wherein the first node is configured to change the first frequency of the first signal by a frequency difference in a time window of the sequence, and the second node is configured to change the second frequency of the second signal by the frequency difference.