Wireless communication system

• US 6,111,909 A
• Filed: 01/23/1998
• Issued: 08/29/2000
• Est. Priority Date: 01/23/1997
• Status: Expired due to Fees

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: Taki, Kazunari
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Webster, Bryan
• Application Number:
  US09/012,824
• Time in Patent Office: 949 Days
• Field of Search: 375/200, 375/202, 375/259, 375/219, 375/222, 375/130, 375/132, 375/133, 375/135, 375/136, 370/310, 370/312, 455/73, 455/561, 455/509, 455/524
• US Class Current: 375/132
• CPC Class Codes: H04B 1/7143 Arrangements for generation of hop patterns

Abstract

A wireless communication system including a base unit and a plurality of remote units, in which two remote units can communicate separately from and simultaneously with communication between the base unit and another remote unit. The wireless communication system can maintain synchronization between the base unit and remote units and process such control signals as call signals without interrupting communication currently in progress. To achieve this, a communication hop frequency data array D is provided for communication use. A control hop frequency data array G is also provided for control use. Both data arrays D and G are stored in a hopping table 36. Data elements In the control hop frequency data array G and in the communication hop frequency data array D are retrieved from the hopping table 36 so that data in the data array G will be distributed regularly throughout the communication hop frequency data array D.

Claims

1. A wireless communication system, comprising:

a base communication unit capable of being connected to an external communication circuit and of being wirelessly communicated with a plurality of remote communication units, the base communication unit including;

an input device that inputs input signals to be transmitted to at least one of the remote communication units;

a reception device that receives reception signals transmitted from at least one of the remote communication units;

a hop frequency data generator that generates an array of hop frequency data according to a predetermined sequence, the hop frequency data array being formed from a control hop frequency data array and a communication hop frequency data array in a manner that data constituting the control hop frequency data array is distributed throughout the communication hop frequency data array; and

a communication device that creates transmission signals through spreading the input signals with the hop frequency data and for creating output signals through despreading the reception signals with the hop frequency data; and

the plurality of remote communication units, each remote communication unit being capable of communicating wirelessly with the base communication unit and with other remote communication units, each remote communication unit including;

an input device that inputs input signals to be transmitted to one of the base unit and the other remote communication units;

a reception device that receives reception signals transmitted from one of the base unit and the other remote communication units;

a hop frequency data generator that generates an array of hop frequency data according to a predetermined sequence, the hop frequency data array being formed from a control hop frequency data array and a communication hop frequency data array in a manner that data constituting the control hop frequency data array is distributed throughout the communication hop frequency data array; and

a communication device that creates transmission signals through spreading the input signals with the hop frequency data and for creating output signals through despreading the reception signals with the hop frequency data.

2. The method according to claim 1, wherein the control hop frequency data array generated by the hop frequency data generator is shared by all of the base communication units and all of the remote communication units to create a single control hop frequency pattern.

3. The method according to claim 2, wherein the communication hop frequency data array generated by the hop frequency data generator is shared by currently communicating communication units only, to create a same communication hop frequency pattern.

4. The system according to claim 3, wherein the communication hop frequency data array is used to create different communication hop frequency patterns for base-to-remote communication and for remote-to-remote communication.

5. A wireless communication system as claimed in claim 1, wherein the amount of data constituting the control hop frequency data array is smaller than the amount of data constituting the communication hop frequency data array.

6. A wireless communication system as claimed in claim 4, wherein the hop frequency data generator generates the communication hop frequency data array so that data constituting the communication hop frequency data array is generated at least two times consecutively.

7. A wireless communication system as claimed in claim 4, wherein the base communication unit further includes a control signal generator that generates a synchronization signal for maintaining synchronization between the base communication unit and the plurality of remote communication units, the control signal generator generating the synchronization signal during a first control frame when the hop frequency data generator generates data in the control hop frequency data array, and

wherein each remote communication unit includes control signal generator that generates a control signal during another control frame which is different from the first control frame, the hop frequency data generator generating data In the control hop frequency data array during the other control frame.

8. A wireless communication system as claimed in claim 7, wherein the control signal generator in the base communication unit generates, during a desired control frame, a call signal to request a connection with one remote communication unit, the control signal generator in the called remote communication unit generating, during the same control frame, a connection acknowledge signal to inform the base communication unit that connection with the base communication unit is possible,

wherein the control signal generator in each remote communication unit generates, during a desired control frame, a call signal to request a connection with one of the base communication unit and the other remote communication units, the control signal generator in the called communication unit generating, during the same control frame, a connection acknowledge signal to inform the calling communication unit that connection with the calling communication unit is possible.

9. A wireless communication system as claimed in claim 4, wherein each remote communication unit further includes a phase shifting device for shifting in phase the communication hop frequency data array generated by the hop frequency data generator to create another communication hop frequency data array to be used for communication between another remote communication unit, the communication device in each remote communication unit generating transmission signals to be transmitted to the other remote communication unit through spreading the input signals with using the other communication hop frequency data array and the control hop frequency data array and generating output signals through despreading the reception signals transmitted from the other remote communication unit with using the other communication hop frequency data array and the control hop frequency data array, thereby performing direct communication with the other remote communication unit.

10. A wireless communication system as claimed in claim 7, wherein the control signal generator in the base communication unit generates a synchronization signal to synchronize the plurality of remote communication units with the base communication unit during a control frame regardless of whether the control frame is provided between communication frames where communication is performed between two remote communication units.

11. A wireless communication system as claimed in claim 4, wherein the hop frequency data generator in each remote communication unit includes a recovery data generator that generates control hop frequency data for use in recovering synchronization with the base communication unit, the communication device in the remote communication unit waiting in a condition capable of receiving a synchronization signal from the base communication unit when the recovery data generator in the remote communication unit generates the hop frequency data for use in recovering synchronization.

12. A wireless communication system as claimed in claim 4, wherein the hop frequency data generator in each remote communication unit is capable of generating a plurality of hop frequency data arrays to be used for communication with other at least two remote communication units, the plurality of hop frequency data arrays being shifted in phase from one another, the communication device in each remote communication unit using one of the a plurality of hop frequency data arrays to communicate with another communication unit.

13. A wireless communication system as claimed in claim 4, wherein the hop frequency data generator in each of the base communication unit and the plurality of remote communication units includes:

a data storage device that stores the hop frequency data array comprised of the communication hop frequency data array and the control hop frequency data array;

an index maintaining device that maintains an index number that is continuously updated synchronously with the synchronization signal;

an index modifying device capable of modifying the index number into a modified index number; and

a data generator that continuously retrieves data from, the communication hop frequency data array and the control hop frequency data array as indicated by the index number outputted from the index modifying device, and thereby outputting the communication hop frequency data array and the control hop frequency data array, data in the communication hop frequency data array being shifted in phase when the index modifying device modifies the index number.

14. A wireless communication system as claimed in claim 13, wherein the index modifying device fails to modify the index number maintained by the index maintaining device when generating the control hop frequency data array and a communication hop frequency data array to be used for communication between the base communication unit and the plurality of remote communication units, and modifies the index number through a calculation with a predetermined value when generating any other types of hop frequency data array.

15. A wireless communication system using a frequency hopping method, the system comprising:

a base communication unit capable of being connected to an external communication circuit; and

a plurality of remote communication units, each being capable of communicating wirelessly with the base communication unit and with other remote communication units,

each of the base communication unit and the plurality of remote communication units including;

a hop frequency data generator that generates hop frequency data according to a prescribed sequence, the generated hop frequency data sequence including a control hop frequency data array and a communication hop frequency data array, data from the control hop frequency data array being distributed throughout the communication hop frequency data array; and

a communication device that creates transmission signals through spreading input signals with using the hop frequency data and for creating output signals through despreading reception signals with using the hop frequency data provided by the hop frequency data generating means.

16. The method according to claim 15, wherein the control hop frequency data array generated by the hop frequency data generator is shared by all of the base communication units and all of the remote communication units to create a single control hop frequency pattern.

17. The wireless communication system according to claim 16, wherein the communication hop frequency data array generated by the hop frequency data generator is shared by currently communicating communication units only, to create a same communication hop frequency pattern.

18. The system according to claim 17, wherein the communication hop frequency data array is used to create different communication hop frequency patterns for base-to-remote communication and for remote-to-remote communication.

19. A wireless communication system as claimed in claim 18, wherein the control hop frequency data array contains fewer data than the communication hop frequency data array.

20. A wireless communication system as claimed in claim 18, wherein the communication hop frequency data is generated at least two times consecutively.

21. A wireless communication system as claimed in claim 18, wherein the base communication unit generates, during a first frame used with data from the control hop frequency data array, control signals containing a synchronization signal for maintaining synchronization between the base communication unit and the remote communication units, the remote communication units receiving the synchronization signal, synchronizing themselves with the base communication unit with using the synchronization signal, and, transmitting prescribed control signals in a control frame different from the first control frame when the synchronization process has been executed successfully.

22. A wireless communication system as claimed in claim 18, wherein a calling communication unit, which is either the base communication unit or one of the remote communication units, transmits, during a control frame, control signals containing a call signal to request a connection with a receiving communication unit, which is either the base communication unit or one of the remote communication units, the receiving communication unit transmitting, during the same control frame, control signals containing a connection acknowledge signal when connection with the calling communication unit is possible.

23. A wireless communication system as claimed in claim 18, wherein the hop frequency data generator in each of the remote communication units is capable of generating a hop frequency data array for communication between two remote communication units, which data array is shifted in phase from the hop frequency data array generated for communication between the base communication unit and a remote communication unit, the communication device in each of the remote communication units performing direct communication with another remote communication unit, using the hop frequency data for communication between two remote communication units to generate transmission signals through spreading the input signals and to generate output signals through despreading the reception signals.

24. A wireless communication system as claimed in claim 18, wherein control signals are transmitted and received between the base communication unit and the remote communication units during control frames in order to synchronize the remote communication units with the base communication unit even when communication is being performed between two remote communication units.

25. A wireless communication system as claimed in claim 18, wherein the hop frequency data generator in each remote communication unit is capable of generating hop frequency data for use in recovering synchronization, the communication device in the remote communication unit waiting in a condition capable of receiving control signals from the base communication unit when the hop frequency data generator in the remote communication unit generates frequency data for use in recovering synchronization.

26. A wireless communication system as claimed in claim 18, wherein the hop frequency data generator in each remote communication unit is capable of generating a plurality of hop frequency data arrays to be used during communication held between a plurality of possible pairs of remote communication units, which data arrays are shifted in phase from one another, the communication device in each remote communication unit using one of the plurality of hop frequency data arrays to perform transmission and reception with another remote communication unit, creating a communication channel different from any other channels used by other pairs of communication units, thereby allowing the plurality of possible pairs of communication units to perform communication simultaneously without interrupting one another.

27. A wireless communication system as claimed in claim 18, wherein the hop frequency data generator includes:

a data storage that stores a communication hop frequency data array and a control hop frequency data array;

an index maintaining device that maintains an index number that is continuously updated synchronous to updates performed in an opposing communication unit; and

an index modifier capable of modifying the index number maintained by the index maintaining device, thereby converting the index number to a modified index number, the hop frequency data generator being capable of using the modified index number as a parameter for indexing data stored by the data storage and generating a communication hop frequency data array whose communication hop frequency data is shifted according to the modified index number.

28. A wireless communication system as claimed in claim 27, wherein the index modifier fails to modify the index number maintained by the index maintaining device when desiring to generate a hop frequency data array either for control or for communication between the base communication unit and a remote communication unit, and modifies the index number through calculation of the index number with a prescribed value when desiring to generate any other type of hop frequency data array.