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US 6,275,517 B1Granted
Wireless communication apparatus using frequency hopping, and method of controlling the apparatus
AssigneeCanon Kabushiki Kaisha
InventorMichihiro Izumi
Life of this patent
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Abstract
A wireless communication apparatus performs communication while changing frequencies according to a frequency hopping pattern, using a memory for storing a plurality of frequencies and designating a frequency to be used in the communication out of the stored plurality of frequencies stored in said memory means based on a first frequency hopping pattern. Depending on whether error is detected in information including data based on a second frequency hopping pattern and transmitted from another wireless communication apparatus, a frequency may be rewritten in the memory. Alternatively, time information in each received frame can be counted or not for use in reading out frequency information from a memory.
Claims44
A wireless communication apparatus which performs communication while changing frequencies according to a frequency hopping pattern, said apparatus comprising:
- memory arranged to store information related to a frequency hopping pattern used in communication;
- a receiver, that receives information indicating a frequency and transmitted from another wireless communication apparatus;
- an error detector, that detects an error in the information received by said receiver;
- and
- a controller that controls said wireless communication apparatus to change a frequency not using the information received by said receiver but using the information that was stored in said memory before error detection by said error detector, when an error in the information received by said receiver is detected by said error detector during communication and to change a frequency using the information received by said receiver when no error is detected by said error detector.
2 more elements
A control method for controlling a wireless communication apparatus which stores a plurality of frequencies and performs communication while changing frequencies according to a frequency hopping pattern, said method comprising:
- a storing step, of storing in a memory, information related to a frequency hopping pattern used in communication;
- a reception step, of receiving information indicating a frequency and transmitted from another wireless communication apparatus;
- an error detection step, of detecting an error in the information received in said reception step;
- and
- a controlling step, of controlling the wireless communication apparatus to change a frequency not using the information received in said reception step but using the information that was stored in the memory before error detection in said error detection step, when an error in the information received in said reception step is detected in said error detection step during communication and to chance a frequency using the information received in said reception step when no error is detected by said error detector.
2 more elements
A wireless communication apparatus performing communication by using a communication frame while changing frequencies, said apparatus comprising:
- a receiver, arranged to receive time information for changing a frequency;
- memory arranged to store frequency information in accordance with time information;
- a counting unit that counts every communication frame and generates time information;
- an error determiner, that determines whether or not there is an error in the time information received by said receiver;
- and
- an output unit that outputs the frequency information from said memory in correspondence with time information outputted from said counting unit,
- wherein said counting unit generates time information using the time information received by said receiver when an error is not detected by said error determiner, or generates time information not using the time information received by said receiver when an error is detected by said error determiner.
4 more elements
A control method for controlling a wireless communication apparatus performing communication by using a communication frame while changing frequencies, said method comprising:
- a reception step, of receiving time information for changing a frequency;
- a counting step, of counting using a counter in every communication frame and generating time information;
- an error determination step, of determining whether or not there is an error in the time information received in said reception step;
- and
- an outputting step, of outputting the frequency information in correspondence with time information outputted from the counter,
- wherein, in said counting step, time information is generated using the time information received in said reception step when an error is not detected in said error determination step, or not using the time information received in said reception step when an error is detected in said error determination step.
3 more elements
A wireless communication apparatus performing communication by using a communication frame while changing frequencies, said apparatus comprising
- a receiver, arranged to receive information, corresponding to a frequency;
- memory arranged to store information in correspondence with frequency information;
- a counting unit that counts every communication frame and generates information corresponding to a frequency;
- an error determiner, that determines whether or not there is an error in the information received by said receiver;
- and
- an output unit that outputs the frequency information in correspondence with information outputted from said counting unit,
- wherein said counting unit generates information using the information received by said receiver when an error is not detected by said error determiner, or generates information not using the information received by said receiver but using the information stored in said memory before error detection by said error determiner when an error is detected by said error determiner.
4 more elements
A control method for controlling a wireless communication apparatus performing communication by using a communication frame while changing frequencies, said method comprising:
- a reception step, of receiving information, corresponding to a frequency;
- a counting step, of counting using a counter in every communication frame for generating information corresponding to a frequency;
- an error determination step, of determining whether or not there is an error in the information received in said reception step;
- and
- an outputting step, of outputting the frequency information in correspondence with the information outputted from the counter,
- wherein, in said counting step, the information is generated using the information received in said reception step when an error is not detected in said error determination step, or not using the information received in said reception step but using the information stored before error determination in said error determination step when an error is detected in said error determination step.
3 more elements
A wireless communication apparatus performing communication by using a communication frame while changing frequencies, said apparatus comprising:
- reception means for receiving time information whose value changes for every communication frame transmitted from another wireless communication apparatus;
- memory means for storing frequency information assigned to respective time information;
- counting means for counting every communication frame and generating time information;
- determination means for determining whether or not there is an error in the time information received by said reception means;
- writing means for writing the time information received by said reception means to said counting means if said determination means determines that there is no error in the received time information;
- continuing means for making said counting means continue counting if said determination means determines that there is an error in the received time information;
- and
- reading means for reading the frequency information from said memory means on the basis of an output value from said counting means,
- wherein the other wireless communication apparatus transmits a synchronizing signal having a predetermined pattern for achieving frame synchronization at a predetermined position in a communication frame, and said reception means receives the synchronizing signal, and said wireless communication apparatus further comprises generation means for generating a clock signal synchronized with a timing at which said synchronizing signal is received and input means for inputting the clock signal to said counting means,
- wherein said generation means includes:
- detecting means for detecting the synchronizing signal;
- a first counter which is initialized at a time of detection of the synchronizing signal and outputs a timing pulse when a time period corresponding to one communication frame elapses;
- a second counter for generating a pulse at a position where the synchronizing signal is detected by said detecting means and outputting a frame position signal indicating a position of a communication frame when a time period corresponding to one communication frame elapses;
- and
- selection means which selects the frame position signal as the clock signal if said detecting means detects the synchronizing signal when the frame position signal is outputted and selects the output from the first counter as the clock signal if said detecting means fails to detect the synchronizing signal for a predetermined number of times consecutively when the frame position signal is outputted.
12 more elements
A control method for controlling a wireless communication apparatus performing communication by using a communication frame while changing frequencies, said method comprising:
- a reception step of receiving time information whose value changes for every communication frame transmitted from another wireless communication apparatus;
- a counting step of counting every communication frame and generating time information;
- a determination step of determining whether or not there is an error in the time information received at said reception step;
- a writing step of writing the time information received at said reception step to a counter if it is determined at said determination step that there is no error in the received time information;
- a continuing step of continuing the counting at said counting step if it is determined at said determination step that there is an error in the received time information;
- and
- a reading step of reading the frequency information from a memory for storing frequency information in correspondence with respective time information on the basis of an output value from the counter,
- wherein the other wireless communication apparatus transmits a synchronizing signal having a predetermined pattern for achieving frame synchronization at a predetermined position in a communication frame, and at said reception step, the synchronizing signal is received, and said control method further comprises a generation step of generating a clock signal synchronized with a timing at which said synchronizing signal is received and an input step of inputting the clock signal to the counter,
- wherein said generation step includes:
- a detecting step of detecting the synchronizing signal;
- a timing pulse output step of outputting a timing pulse when a time period corresponding to one communication frame elapses from a time of detection of the synchronizing signal;
- a frame position signal output step of generating a pulse at a position where the synchronizing signal is detected at said detecting step and outputting a frame position signal indicating a position of a communication frame when a time period corresponding to one communication frame elapses;
- and
- a selection step of selecting the frame position signal as the clock signal if the synchronizing signal is detected at said detecting step when the frame position signal is outputted, or the timing pulse as the clock signal if it is failed to detect the synchronizing signal at said detecting step for a predetermined number of times consecutively when the frame position signal is outputted.
11 more elements
Dependencies are inferred from the claim text.