Wireless communication device

• US 6,240,126 B1
• Filed: 09/17/1997
• Issued: 05/29/2001
• Est. Priority Date: 09/18/1996
• Status: Expired due to Term

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: Wakayama, Hironobu, Ohashi, Tsuyoshi
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Liu, Shuwang
• Application Number:
  US08/932,177
• Time in Patent Office: 1,350 Days
• Field of Search: 370/343, 370/344, 370/480, 375/130, 375/132, 375/131, 375/133, 375/137
• US Class Current: 375/132
• CPC Class Codes: H04B 1/7143 Arrangements for generation of hop patterns
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0016 involving special memory structures, e.g. look-up tables
• CPC Class Codes: H04L 1/20 using signal quality detector

Abstract

Test hopping frequency data stored in the hopping frequency data table 35b is set in the hopping table 26 as a data setting signal w. Digital test data is transmitted while hopping the carrier wave frequency among the frequency candidates which correspond to the hopping frequency data thus set in the hopping table 26. Frequency candidates which have attained high recognition rate for the test data are selected as a carrier wave hopping pattern, and are set in the hopping table 26. Bi-directional communication will be performed thereafter while the carrier wave frequency hops according to the hopping pattern.

Claims

1. A wireless communication device, comprising:

communication means capable of performing bi-directional communication with data with carrier wave frequency hopping;

test control means for controlling the communication means to perform bi-directional test communication with digital test data and error-detecting code, while successively hopping carrier wave frequency among a predetermined plurality of frequency candidates;

means for calculating, using the error-detecting code, a recognition rate attained onto the digital test data by the bi-directional test communication;

means for selecting, from the plurality of frequency candidates, several frequency candidates based on the calculated recognition rate for the digital test data;

means for setting a hopping pattern based on the selected several frequency candidates; and

communication control means for controlling, after completion of the bi-directional test communication, the communication means to perform bi-directional communication with desired data while successively hopping carrier wave frequency among the set hopping pattern.

2. A wireless communication device as claimed in claim 1, further comprising means for randomly rearranging the selected frequency candidates into the hopping pattern.

3. A wireless communication device as claimed in claim 1, wherein the test control means controls the communication means to repeatedly perform the bi-directional test communication at a predetermined time interval.

4. A wireless communication device as claimed in claim 1,

wherein the test control means controls the communication means to perform the bi-directional test communication using the digital test data and check sum data that is defined for the digital test data, according to the predetermined plurality of frequency candidates,

wherein the recognition rate calculating means includes means for calculating an error rate of the received test data using the check sum data at each of the plurality of frequency candidates; and

wherein the selecting means includes error rate-dependent selection means for selecting several frequency candidates dependent on the calculated error rates.

5. A wireless communication device as claimed in claim 4, wherein the error rate-dependent selection means includes:

means for rearranging data of the plurality of frequency candidates in an order of the magnitude of their error rates, the plurality of frequency candidates including a total L number of frequency candidates where L is an integer higher than one; and

means for selecting, from the thus rearranged L number of frequency candidates, K number of frequency candidates from a first candidate that has the minimum error rate and that is located first among the L number of candidates toward a K-th candidate that has the K-th minimum error rate and that is located K-th among the plurality of frequency candidates where K is an integer higher than one and lower than L.

6. A wireless communication device as claimed in claim 4, wherein the error rate-dependent selection means includes means for selecting several frequency candidates whose error rates are smaller than a predetermined threshold.

7. A wireless communication device as claimed in claim 6, further comprising means for correcting errors in received data, the predetermined threshold being set smaller than a limit error rate for the error correction means by a predetermined amount.

18. A wireless communication device as claimed in claim 4, wherein the test control means further includes:

transmission control means for controlling the communication means to transmit, according to each frequency candidate, the digital test data and the check sum data to a remote communication device; and

reception control means for controlling the communication means to receive, according to the frequency candidate, the digital test data and the check sum data transmitted back from the remote communication device.

8. A wireless communication device, comprising:

means for storing data indicative of a condition for selecting frequencies;

wherein the storing means maintains the data indicative of the condition both when the communication means performs communication and when the communication means stops performing communication,

wherein the storing means includes an initial state memory storing data of a predetermined initial condition for selecting frequencies; and

an operational state memory storing data of a changed condition for selecting frequencies;

means for performing communication with a carrier wave while successively selecting frequencies of the carrier wave according to the condition, data indicative of which is being stored in the storing means;

means for measuring a reception state of communication at each of the successively-selected frequencies; and

means for changing the data indicative of the condition stored in the storing means according to the measured reception state.

9. A wireless communication device as claimed in claim 8, wherein the data indicative of the condition is constructed from data of the reception state measured by the measuring means for each frequency.

10. A wireless communication device as claimed in claim 8, wherein the data indicative of the condition is constructed from attribute data indicative of whether or not each frequency can be selected, the attribute data being determined dependent on the reception state measured by the measuring means.

11. A wireless communication device as claimed in claim 8, wherein the storing means includes a non-volatile memory.

12. A wireless communication device as claimed in claim 8, further comprising a power supply for supplying power to the device, wherein the storing means includes:

a volatile memory; and

a back up power supply for supplying power to the volatile memory with regardless of whether the power supply stops supplying power to the device.

13. A wireless communication device as claimed in claim 8, wherein the data of the changed condition in the operational state memory is constructed from data indicative of the measured reception state.

14. A wireless communication device as claimed in claim 8, wherein the data of the changed condition in the operational state memory is constructed from attribute data indicative of whether or not each frequency can be selected, the attribute data being determined dependent on the reception state measured by the measuring means.

15. A wireless communication device as claimed in claim 14, wherein the initial state memory stores therein data indicative of a predetermined plurality of frequencies.

16. A wireless communication device as claimed in claim 15, wherein the communication means successively selects frequencies from the plurality of frequencies while referring to the operational state memory.

17. A wireless communication device as claimed in claim 8, wherein the communication means includes means for selecting either one of the initial condition stored in the initial state memory and the changed condition stored in the operational state memory to select frequencies at the initial stage of each communication.