JP2008131156A - Wireless apparatus and bidirectional wireless system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless apparatus and a bidirectional wireless system in which communication can be improved by absorbing the difference of antenna gain between a transmitter and a receiver. <P>SOLUTION: A master unit 10 stores the correspondence of the difference of antenna gain between a slave unit 20 and the master unit 10 and the spread length for transmission depending on the difference of gain between the slave unit 20 and the master unit 10. A wireless signal from the slave unit 20 is received and demodulated at a receiving section 12b, the spread length for the wireless signal demodulated is specified as the spread length for transmission of the slave unit 20, the spread length for transmission of the master unit 10 is specified for the spread length for transmission of the slave unit 20 based on the correspondence depending on the difference of gain thus stored, and a transmitting section 12a performs transmission processing to the slave unit by the spread length for transmission of the master unit 10 thus specified. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an event-type bidirectional wireless system, and more particularly, to a wireless device and a bidirectional wireless system that satisfactorily communicate by absorbing an antenna gain difference between transmission and reception.

A wireless device used in a conventional event-type two-way wireless system is a wireless device that operates on a weak radio wave adopting a spread spectrum (SS) method.
A conventional event-type two-way radio system will be described with reference to FIG. FIG. 9 is a schematic diagram of a conventional event-type two-way radio system.
The conventional event type two-way radio system includes a radio of the base unit 1 having the transmission unit 1a and the reception unit 1b, and a radio of the slave unit 2 having the transmission unit 2a and the reception unit 2b. The input device is operated to transmit an operation command from the slave unit 2 to the master unit 1, and the master unit 1 operates according to the command.

In addition, the base unit 1 transmits a command transmission status response and the base unit 1 status information to the handset 2.
That is, the conventional event-type bidirectional wireless system is a weak wireless system capable of bidirectional communication (half duplex) employing SS.

Note that the diffusion gain in the SS system is expressed by the following equation.
Diffusion gain = 10 · log (Chip Rate / Bit Rate) [dB]
Here, Chip Rate is the bit rate of the spreading code, and its unit is cps (chip
par second), Bit Rate is the bit rate of the baseband signal, and its unit is bps (bit
par second). One bit of the spread code is called a chip.
FIG. 10 shows the relationship among the chip, the information code, and the spreading code when the spreading length = 8 bits and the spreading factor = 8. FIG. 10 is a diagram showing the relationship among chips, information codes, and spreading codes.

  As related prior arts, Japanese Patent Application Laid-Open No. 08-037476 (Patent Document 1), Japanese Patent Application Laid-Open No. 2003-324409 (Patent Document 2), Japanese Patent Application Laid-Open No. 2004-159250 (Patent Document 3), and Japanese Patent Application Laid-Open No. 2005. No. 072749 (Patent Document 4).

  Patent Document 1 discloses a configuration for automatically adjusting a gain on the receiving side in a wireless communication system, and Patent Document 2 discloses a spreading length of a control channel on a transmitting side and a spread of a communication channel in the wireless communication system. It is shown that the frames of the control channel and the speech channel are configured to be a common multiple of the length, and the start timing of the frames is synchronously established as the frame timing.

  Patent Document 3 discloses a configuration for performing data abnormality determination and changing the gain of an amplifier on the reception side in a wireless communication system. Patent Document 4 discloses a transmission / reception antenna in a wireless communication system. A configuration is shown in which a communication path state is estimated based on gain and transmission loss, and a communication method is selected.

Japanese Patent Application Laid-Open No. 08-037476 JP 2003-324409 A JP 2004-159250 A Japanese Patent Laying-Open No. 2005-072749

  However, in conventional event-type two-way radio systems, when used in remote keyless entry, the slave unit is often configured with a loop antenna to achieve low cost and miniaturization, and the master unit is mounted on the car. Therefore, a helical antenna having a good antenna gain is often used, and there is a problem that the antenna gain difference occurs between the two antennas, and the sensitivity deteriorates in communication from the parent device to the child device.

  For example, when the antenna gain of the loop antenna of the slave unit is about −20 dBi and the antenna gain of the helical antenna of the base unit is about −5 dBi, the antenna gain difference is about 15 dB.

  In order to realize bidirectional communication, in the case of communication from the parent device to the child device, the sensitivity is deteriorated by about 15 dB. Therefore, the sensitivity at which communication is possible is limited by the communication sensitivity from the parent device to the child device. Even if a master unit having a good antenna gain is used, the sensitivity of bidirectional communication is governed by the antenna gain of the slave unit. Therefore, although it is conceivable to use a slave unit having a good antenna gain, it is not possible to reduce the cost of the slave unit.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radio and a bidirectional radio system that can absorb a difference in antenna gain between a transmitter and a receiver and improve communication.

  The present invention for solving the problems of the above-described conventional example is a radio of a master unit that performs two-way wireless communication with a slave unit, and the master unit has an antenna gain of the slave unit and an antenna of the master unit Stores the correspondence between the gain difference from the gain and the spreading length for transmission of the slave unit and the spreading length for transmission of the master unit according to the gain difference, and receives and demodulates the radio signal from the slave unit The spread length at the time of being demodulated is specified as the spread length for transmission of the slave unit, and the transmission length of the master unit with respect to the spread length for transmission of the slave unit specified based on the correspondence relationship according to the stored gain difference A spreading length is specified, and transmission processing is performed on the slave unit by the transmission spreading length of the specified master unit.

  The present invention relates to a slave unit that performs two-way wireless communication with a master unit, and the slave unit determines a gain difference between an antenna gain of the slave unit and an antenna gain of the master unit, and the gain difference. Corresponding relationship between the spreading length for transmission of the corresponding slave unit and the spreading length for reception of the slave unit is stored, and when transmission processing is performed to the master unit with the spreading length for specific transmission, depending on the stored gain difference The spread length for reception of the slave unit relative to the spread length for transmission of the slave unit that has been subjected to transmission processing based on the corresponding correspondence is specified, and the reception process for the master unit is performed based on the spread length for reception of the specified slave unit It is characterized by.

  According to the present invention, in the above wireless device, the slave unit changes the diffusion length for transmission of the slave unit in accordance with the reception sensitivity, and changes based on the correspondence corresponding to the stored gain difference. The spread length for reception of the slave unit with respect to the spread length of the slave unit is specified, and reception processing for the base unit is performed with the spread length for reception of the specified slave unit.

  According to the present invention, in the above wireless device, the base unit stores, in the storage unit, one diffusion length as a specific diffusion length among the transmission diffusion lengths of the corresponding slave units, and the specific diffusion When the radio signal from the slave unit is received and demodulated by the length and cannot be demodulated, the radio signal from the slave unit is received using another spread length among the transmission spreading lengths of the slave units that are in the corresponding relationship -The demodulating process is performed, and the spreading length when demodulating is specified as the spreading length for transmission of the slave unit.

  According to the present invention, in the above wireless device, the master device cannot receive and demodulate the wireless signal from the slave device by using another diffusion length among the transmission spreading lengths of the slave devices in the corresponding relationship, and cannot demodulate. In this case, the radio signal from the slave unit is received and demodulated using another spread length among the transmission spread lengths of the slave units in the corresponding relationship.

  The present invention relates to the above wireless device, in the case where the master unit selects the one having the smallest spread length among the transmission spread lengths of the slave units in the correspondence relationship as a specific spread length and cannot be demodulated. The other spreading length that is next larger than the specific spreading length is selected from among the spreading lengths for transmission of the slave units.

  According to the present invention, in the above wireless device, when the master unit cannot demodulate, the spreading lengths are selected in ascending order of the spreading length from among the unselected spreading lengths for transmission of the slave units in correspondence. It is characterized by that.

  The present invention is characterized in that, in a bidirectional radio system, the master unit and the slave unit are included.

  According to the present invention, in a base unit radio that performs two-way wireless communication with a slave unit, the master unit determines the gain difference between the antenna gain of the slave unit and the antenna gain of the master unit, and the gain difference. Corresponding relationship between the spreading length for transmission of the slave unit and the spreading length for transmission of the base unit is stored, the radio signal from the slave unit is received and demodulated, and the spreading length when demodulated can be The transmission length of the master unit relative to the transmission length of the slave unit specified based on the correspondence relationship corresponding to the stored gain difference, and the specified master unit Since the transmission processing is performed on the slave unit by the transmission spreading length of the transmission, there is an effect that the antenna gain difference between the slave unit and the master unit can be absorbed to improve the communication.

  According to the present invention, in the wireless device of the child device that performs two-way wireless communication with the parent device, the child device has the gain difference between the antenna gain of the child device and the antenna gain of the parent device, and the gain difference. Corresponding relationship between the spreading length for transmission of the corresponding slave unit and the spreading length for reception of the slave unit is stored, and when transmission processing is performed to the master unit with the spreading length for specific transmission, depending on the stored gain difference The spread length for reception of the slave unit with respect to the transmission spread length of the slave unit that has been subjected to transmission processing based on the correspondence relationship is specified, and the reception process for the master unit is performed based on the spread length for reception of the specified slave unit Therefore, there is an effect that the antenna gain difference between the slave unit and the master unit can be absorbed to improve communication.

  According to the present invention, the slave unit changes the diffusion length for transmission of the slave unit in accordance with the reception sensitivity, and changes the diffusion length for transmission of the slave unit based on the correspondence relationship according to the stored gain difference. The above-mentioned wireless device is configured to specify the diffusion length for reception of the child device with respect to the master device and perform reception processing for the parent device by the specified diffusion length for reception of the child device. Therefore, depending on the reception sensitivity of the child device, It is possible to improve the communication by absorbing the antenna gain difference between the main unit and the base unit.

  According to the present invention, the master unit stores, in the storage unit, one spreading length as a specific spreading length among the transmission spreading lengths of the slave units in the correspondence relationship, and the child unit uses the specific spreading length. When receiving and demodulating the radio signal from the machine and unable to demodulate it, receive and demodulate the radio signal from the slave using other spreading lengths among the transmission spreading lengths of the corresponding slave units However, since the above-mentioned wireless device specifies the spreading length when demodulated as the spreading length for transmission of the slave unit, even if it cannot be demodulated with a specific spreading length, it can be detected from the other spreading lengths in the corresponding relationship. The transmission spreading length can be specified, and the antenna gain difference between the slave unit and the master unit can be absorbed to improve communication.

  According to the present invention, when the master unit receives and demodulates the radio signal from the slave unit using another spreading length among the transmission spreading lengths of the slave units in the correspondence relationship, Of the spreading lengths for transmission of slave units that are in a correspondence relationship, the above radio unit that receives and demodulates radio signals from the slave units using other spreading lengths is used, so it cannot be demodulated even with other spreading lengths. However, the diffusion length for transmission of the parent device can be specified from the other diffusion lengths in the corresponding relationship, and there is an effect that the antenna gain difference between the child device and the parent device can be absorbed to improve the communication.

  According to the present invention, when the base unit selects the one with the shortest spreading length from the transmission spreading lengths of the slave units in a correspondence relationship as a specific diffusion length and cannot demodulate, the child in the correspondence relationship Since the above-mentioned radio unit selects the other spreading length that is the second largest after the specific spreading length among the spreading lengths for transmission of the unit, it is close to the original spreading length when the reception sensitivity of the slave unit deteriorates The spreading length for transmission of the parent device can be specified from the spreading length, and there is an effect that the antenna gain difference between the child device and the parent device can be absorbed in a short period of time and communication can be improved.

  According to the present invention, when the base unit cannot demodulate, the radio unit selects a spreading length in ascending order of spreading length from among unselected spreading lengths for transmission of slave units in a corresponding relationship. Therefore, it is possible to identify the spreading length for transmission of the parent device from the spreading length in the order close to the original spreading length, and to improve communication by absorbing the antenna gain difference between the child device and the parent device in a short period of time There is.

  According to the present invention, since the bidirectional wireless system includes the parent device and the child device, an antenna gain difference between the child device and the parent device can be absorbed to improve communication.

Embodiments of the present invention will be described with reference to the drawings.
[Outline of the embodiment]
In the bidirectional wireless system according to the embodiment of the present invention, the receiving side (master side) receives the same spreading length as the transmission spreading length on the transmitting side (slave unit side), and further, The spreading length corresponding to the antenna gain difference between transmission and reception is specified as the spreading length for transmission on the master unit side, and the master unit side transmits with the specified spreading length, and the slave unit side determines the spreading length for its own transmission. Thus, reception is performed with the spreading length corresponding to the antenna gain difference as the spreading length for reception, and the antenna gain difference between transmission and reception can be absorbed to improve bidirectional communication.

  In addition, the bidirectional wireless system according to the embodiment of the present invention allows the master unit to receive and transmit with the candidate spreading length within a range that considers the antenna gain difference even if the slave unit changes the spreading length according to the sensitivity. Performs demodulation processing, identifies the spread length that can be demodulated as the spread length for transmission of the slave unit, and sets the spread length according to the antenna gain difference between transmission and reception for the specified spread length for transmission on the base unit side Specified as a length, the master unit transmits with the specified spreading length, and the slave unit receives with the spreading length corresponding to the antenna gain difference as the spreading length for reception with respect to its own spreading length Thus, the antenna gain difference between the transmission and reception can be absorbed to improve the bidirectional communication.

[Outline of bidirectional wireless system: Fig. 1]
An event type bidirectional radio system according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of an event-type bidirectional radio system according to an embodiment of the present invention.
As shown in FIG. 1, an event-type bidirectional wireless system (this system) according to an embodiment of the present invention includes a parent wireless device 10 and a child wireless device 20, both of which are bidirectional SS. It communicates with a wireless system.

  In particular, the present system employs a direct spreading method (DS method: Direct Sequence) in order to realize the SS method. In the DS system, spectrum spreading is realized by directly multiplying a signal whose spectrum is to be spread by a signal (spreading code) of a much wider band.

The base transceiver 10 includes a controller 11 and a wireless module 12, and the wireless module 12 includes a transmitter (TX) 12a and a receiver (RX) 12b.
The slave radio device 20 includes a control unit 21 and a radio unit module 22, and the radio unit module 22 includes a transmission unit (TX) 22a and a reception unit (RX) 22b.

[Configuration of transmitter: Fig. 2]
Next, a direct-spreading transmitter constituting the transmission units (TX) 12a and 22a will be described with reference to FIG. FIG. 2 is a configuration block diagram of a direct spreading transmitter.
As shown in FIG. 2, the transmitter includes a carrier generator 31 that generates a carrier wave, a data modulator 32 that modulates transmission data using the carrier wave output from the carrier generator 31, and a code generator that generates a spreading code. 33, a wideband code modulator 34 for performing wideband code modulation on the modulation signal output from the data modulator 32 with the spreading code output from the code generator 33, and an antenna for transmitting the wideband code modulated signal 35.

The code generator 33 and the wideband code modulator 34 spread the modulated signal with a spreading length designated by an instruction from the control unit.
The code generated by the code generator 33 includes an error correction code.

[Receiver: Fig. 3]
Next, a direct-spreading receiver constituting the receiving units (RX) 12b and 22b will be described with reference to FIG. FIG. 3 is a configuration block diagram of a direct spreading receiver.
As shown in FIG. 3, the receiver includes an antenna 41 that receives radio waves, a code synchronization / tracking 42 that tracks synchronization using a tracking code for a signal input from the antenna 41, and a tracking And a code generator 43 that outputs a code when synchronization is input by inputting a synchronization signal from the code synchronization / tracking 42, and a signal from the antenna 41 is input and output from the code generator 43. A code demodulator 44 that demodulates the received code, a carrier wave generator 45 that generates a carrier wave, a data demodulator 46 that demodulates the code demodulated signal using a carrier wave and outputs data, and a signal received by the antenna 41 And an electric field intensity detector 47 for detecting the electric field intensity (sensitivity).

The code generator 43 and the code demodulator 44 despread the received signal with the spreading length specified by the instruction from the control unit.
The electric field strength data output from the electric field strength detector 47 is input to the control unit, and the control unit selects the transmission diffusion length corresponding to the electric field strength (sensitivity) and sets the code generator 33 and the wideband code modulator 34. It comes to control.
The detected electric field strength may be displayed on the display unit of the wireless device, and the user may manually select the transmission diffusion length using a switch.

[Diffusion length and diffusion gain: Fig. 4]
Next, the diffusion gain at each diffusion length will be described with reference to FIG. FIG. 4 is a diagram showing the diffusion gain at each diffusion length.
As shown in FIG. 4, when the spreading length (bit) is 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, the spreading gain (dB) is 0, 3, 6, 9 12, 15, 18, 21, 24, 27.

[Diffusion length and gain difference: Fig. 5]
The difference (gain difference) [dB] from each diffusion length will be described with reference to FIG. FIG. 5 is a diagram illustrating a difference from each diffusion length.
In FIG. 5, the difference (gain difference) is obtained from FIG. 4 with the vertical axis as, for example, the transmission length (bit) for transmission of the parent device and the horizontal axis as, for example, the diffusion length (bit) for transmission of the child device. . For example, from FIG. 4, if the spreading length of the master unit is 512 bits, the spreading gain is 27 dB. If the spreading length of the slave unit is 16 bits, the spreading gain is 12 dB, so the gain difference is 15 dB (= 27 dB− 12 dB).

  As for the spreading length for reception, in order to perform transmission / reception between the master unit and the slave unit, the master unit performs reception (despreading) with the same spreading length as the transmission length of the slave unit, The slave unit needs to perform reception (despreading) with the same spreading length as the transmission length of the master unit.

Here, in this system, if the gain difference is measured or calculated in advance from the antenna gain of the master unit and the antenna gain of the slave unit, the optimum diffusion length can be determined according to the gain difference.
For example, when the gain difference is 6 dB and the spreading length for transmission of the slave unit is 64 bits, it can be determined that 256 bits is suitable for the spreading length for transmission of the master unit from FIG.

The slave unit stores an antenna gain difference with the master unit and a transmission spreading length and a reception spreading length corresponding to the gain difference in an internal storage unit (not shown). When the credit spread length is specified, the reception spread length corresponding to the antenna gain difference can be specified.
The master unit stores an antenna gain difference with the slave unit and a reception spreading length and a transmission spreading length according to the gain difference in an internal storage unit (not shown). When the transmission spreading length of the slave unit is specified, the transmission spreading length corresponding to the antenna gain difference can be specified.
Accordingly, the parent device and the child device store the correspondence relationship of FIG. 5 in a table or calculation formula in the internal storage unit.

[Specify the diffusion length for transmission of the master unit]
If the extension length of the slave unit is fixed, the diffusion length of the master unit can also be fixed from the gain difference. However, as a feature of this system, the slave unit changes the transmission spread length according to the sensitivity, and the master unit In response to this, the transmission spreading length is searched and specified.
When the diffusion length is lowered, the sensitivity is increased and the transmission speed is lowered. When the diffusion length is increased, the sensitivity is lowered and the transmission speed is increased.

For example, if the slave unit has a transmission spread length of 64 bits, but the sensitivity has deteriorated, the transmission spread length has been lowered to 32 bits. Cannot be received.
Therefore, as reception processing of the master unit, when reception processing is performed with a spreading length of 64 bits and cannot be demodulated within a specific time, when reception processing is performed with a spreading length of 32 bits and demodulation is performed within the specific time, the spreading length Is specified as the spreading length for transmission of the slave unit, and the spreading length for transmission of the base unit according to the difference corresponding to the specified spreading length is specified.

  Usually, the extension length when the sensitivity of the slave unit is good is held in the slave unit as a reference value, and the slave unit determines the diffusion length for transmission according to the electric field strength (sensitivity) detected by the electric field strength detector 47. The transmission is performed with the spread length, and the receiving master repeats reception processing with the spread length sequentially increased from the spread length of the slave unit's reference value. Specify as long.

[Processing without sensitivity]
In addition, if the slave unit does not detect the electric field strength and performs transmission processing with the reference value diffusion length, but there is no response from the master unit, the slave unit performs transmission processing with the diffusion length increased from the reference value diffusion length. In response, the master unit may perform the above reception process to specify the transmission spread length of the slave unit.
In this case, if there is no response from the parent device, the child device repeats transmission processing by sequentially increasing the transmission spreading length, and the parent device repeats reception processing by sequentially increasing the reception diffusion length accordingly. By doing so, it is possible to identify an appropriate diffusion length in transmission / reception that absorbs the antenna gain difference between the parent device and the child device, thereby realizing good communication.

[Data structure of instruction cycle: FIG. 6]
Next, an instruction cycle for notifying system information in this system will be described with reference to FIG. FIG. 6 is a data configuration diagram of an instruction cycle.
In FIG. 6, the antenna gain of the slave unit is −20 dBi, and the antenna gain of the master unit is −5 dBi. Therefore, the antenna gain difference is 15 dB.
Therefore, the spreading length for transmission of the slave unit and the spreading length for reception of the master unit are set to 64 chips (bit), the spreading length for transmission of the master unit and the spreading length for reception of the slave unit are set to 512 chips (bit), The antenna gain difference can be absorbed by changing the spreading length between the transmission side and the reception side.

  In FIG. 6, the root of the arrow is the transmitting side, the tip of the arrow indicates the receiving side, “G” is a guard signal, used when turning on / off the radio signal, and “P” is Preamble sync signal, used to establish synchronization, “S” is Sync signal, used to detect head data, “Rx int” is a reception wait signal, used to search received signal, “Info” is system information, used to send system information, “Data_Field” is data, used to send user data, “Ack / Nak” is Ack / Nak signal, Used to respond system information to the sender.

[Data structure of response cycle: Fig. 7]
Next, a response cycle for notifying response information in this system will be described with reference to FIG. FIG. 7 is a data configuration diagram of a response cycle.
Also in FIG. 7, the antenna gain difference between the master unit and the slave unit is 15 dB, but the spread length for transmission of the slave unit and the spread length for reception of the master unit are 64 chips (bit), By setting the spreading length and the spreading length for reception of the slave unit to 512 chips (bits), the antenna gain difference can be absorbed by changing the spreading length between the transmitting side and the receiving side.
Signal symbols are the same as those in FIG.

  FIG. 6 differs from FIG. 7 in that in FIG. 6, “Info” and “Data_filled” are transmitted from the slave unit, the master unit receives these signals, and when received, the master unit sets “Ack / Nak” to the slave unit. In FIG. 7, “Info” and “Data_filled” are transmitted from the parent device and the child device receives those signals. When the child device receives these signals, the child device transmits “Ack / Nak” to the parent device. It is a point.

[Process for identifying transmission spreading length in control unit of base unit]
Next, a process for specifying a transmission spreading length in the control unit 11 of the master unit will be described with reference to FIG. FIG. 8 is a flowchart of processing for specifying a transmission spreading length in the control unit of the parent device.
As shown in FIG. 8, when the sensitivity of the slave unit is good, the control unit 11 of the master unit receives so as to receive with a predetermined spreading length for reception corresponding to the spreading length for transmission of the slave unit. The receiver 12b is instructed (S1), and the receiver 12b receives the signal with the spreading length and performs demodulation processing.

  Then, it is determined whether or not the received signal has been demodulated (S2). If it has been demodulated (in the case of Yes), the spreading length used for demodulation is specified as the spreading length for transmission of the slave unit (S3), The transmission spread length of the master unit corresponding to the antenna gain difference is specified with respect to the transmission spread length of the specified slave unit (S4).

When the received signal cannot be demodulated in the determination process S2 (in the case of No), it is determined whether or not the reception process has been completed for all spreading lengths within a range that considers the antenna gain difference (S5).
“Within an antenna gain difference range” in FIG. 5, assuming that the antenna gain difference is 15 dB, the spreading length used by the base unit in the reception process is 16, 8, 4, and 2 bits. Therefore, the diffusion length candidate specified by the gain difference falls within the range.
Among the candidates, the transmission spreading length of the selected master unit is 512, 256, 128, and 64 bits.

  When the reception process is completed for all the candidate spreading lengths in the determination process S5 (in the case of Yes), the process is terminated assuming that the reception signals of the slave units cannot be demodulated with all the candidate spreading lengths.

If it is determined in the determination process S5 that reception processing has not been completed for all candidate spreading lengths (in the case of No), reception is instructed to the receiving unit 12b with the next largest spreading length among the candidates (S6), and demodulation Let the process do.
And it returns to determination process S2 and it is determined whether it was able to demodulate.

In process S1, when the sensitivity of the slave unit is good, the spread length for reception of the master unit is stored in advance corresponding to the spread length for transmission of the slave unit. Is the smallest of the candidates within the range considering the antenna gain difference.
Accordingly, in the process S6, the reception / demodulation process is repeatedly performed in order of increasing diffusion length among candidates whose base unit has not completed the reception / demodulation process.

[Application example]
In the above example, reception / demodulation processing is repeatedly performed in ascending order of spreading length. However, reception / demodulation processing may be repeatedly performed in descending order of spreading length.

[Effect of the embodiment]
According to the radio in this system, the gain difference can be absorbed by changing the gain difference between the antenna gain of the slave unit and the antenna gain of the master unit between the transmission spreading length and the receiving spreading length. There is an effect that communication can be improved.

  Further, according to the present system, even if the transmission-side radio changes the transmission length depending on the sensitivity state and transmits, the reception-side radio has a candidate spread length within a range that considers the antenna gain difference. In order to receive and demodulate sequentially, specify the spread length that can be demodulated as the spread length on the transmission side, and specify the spread length for transmission of the radio on the reception side according to the antenna gain difference from the specified spread length Therefore, the transmission spreading length of the receiving-side radio can be specified in accordance with the change of the spreading length of the transmitting-side radio, and there is an effect of improving the bidirectional communication.

  Moreover, according to this system, an inexpensive slave unit can be realized using a conventional loop antenna without using a slave unit having a good antenna gain, and communication from the master unit to the slave unit can be achieved. There is an effect that sensitivity can be improved.

  INDUSTRIAL APPLICABILITY The present invention is suitable for a radio and a two-way radio system that can absorb a difference in antenna gain between a transmitter and a receiver and improve communication.

1 is a configuration block diagram of an event-type bidirectional wireless system according to an embodiment of the present invention. It is a block diagram of the configuration of a direct spreading transmitter. It is a block diagram of a direct spreading receiver. It is a figure which shows the diffusion gain in each spreading | diffusion length. It is a figure which shows the difference from each spreading | diffusion length. It is a data block diagram of an instruction cycle. It is a data block diagram of a response cycle. It is a flowchart of the process which specifies the spreading | diffusion length for transmission in the control part of a main | base station. It is the schematic of the conventional event type | formula two-way radio system. It is a figure which shows the relationship between a chip | tip, an information code, and a spreading code.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Master unit, 1a ... Transmitter, 1b ... Receiver, 2 ... Slave unit, 2a ... Transmitter, 2b ... Receiver, 10 ... Master unit, 11 ... Control unit, 12 ... Wireless module, 12a ... Transmitter, 12b: receiving unit, 20 ... slave unit, 21 ... control unit, 22 ... wireless module, 22a ... transmitting unit, 22b ... receiving unit, 31 ... carrier wave generator, 32 ... data modulator, 33 ... code generator, 34 ... Wideband code modulator, 35 ... antenna, 41 ... antenna, 42 ... code synchronization / tracking, 43 ... code generator, 44 ... code demodulator, 45 ... carrier wave generator, 46 ... data demodulator, 47 ... field strength detector

Claims (8)

A wireless device of a parent device that performs two-way wireless communication with a child device,
The master unit includes a gain difference between an antenna gain of the slave unit and an antenna gain of the master unit, a spreading length for transmission of the slave unit according to the gain difference, and a spreading length for transmission of the master unit. Is stored, the radio signal from the slave unit is received and demodulated, the spread length when the demodulator is able to be demodulated is specified as the spread length for transmission of the slave unit, and according to the stored gain difference Based on the correspondence relationship, the transmission length of the master unit for the specified transmission length of the slave unit is specified, and transmitted to the slave unit according to the specified transmission length of the master unit for transmission. A wireless device that performs processing. A slave unit that performs two-way wireless communication with the master unit,
The slave unit includes a gain difference between an antenna gain of the slave unit and an antenna gain of the master unit, a spreading length for transmission of the slave unit and a spreading length for reception of the slave unit according to the gain difference, For the transmission of the slave unit that has been subjected to the transmission processing based on the correspondence relationship according to the stored gain difference when the transmission processing is performed to the base unit with a specific transmission spreading length. A wireless device characterized by specifying a spreading length for reception of the slave unit with respect to a spreading length, and performing reception processing on the master unit with the specified spreading length for reception of the slave unit.   The slave unit changes the spreading length for transmission of the slave unit corresponding to the reception sensitivity, and the slave unit for the transmission spreading length of the slave unit changed based on the correspondence relationship corresponding to the stored gain difference 3. The wireless device according to claim 2, wherein a reception spreading length for the reception is specified, and reception processing for the parent device is performed based on the specified diffusion length for reception of the slave device.   The master unit stores, in the storage unit, one spread length as a specific spread length among the transmission spread lengths of the slave units in the correspondence relationship, and the radio signal from the slave unit is stored with the specific spread length. Can be received, demodulated, and demodulated by receiving and demodulating the radio signal from the slave unit using the other spreading lengths of the corresponding spreading lengths 2. The wireless device according to claim 1, wherein a spreading length at the time of transmission is specified as a spreading length for transmission of the slave unit.   The master unit receives and demodulates the radio signal from the slave unit using another spread length among the transmission spreading lengths of the slave units in the correspondence relationship, and the slave unit in the correspondence relationship cannot be demodulated. 5. The radio device according to claim 4, wherein a radio signal from the slave unit is received and demodulated using another spread length among transmission spreading lengths of the unit.   When the base unit selects a specific spreading length among the spreading lengths for transmission of the slave units in the correspondence relationship as a specific spreading length and cannot be demodulated, the master unit transmits the slave unit in the correspondence relationship. 5. The radio apparatus according to claim 4, wherein a diffusion length that is next larger than the specific diffusion length is selected from among the diffusion lengths.   6. The base unit, when unable to demodulate, selects a spreading length in ascending order of spreading length from among unselected spreading lengths for transmission of slave units in a corresponding relationship. Radio.   A bidirectional wireless system comprising the parent device according to any one of claims 1 to 4 and the child device according to claim 2 or 3.

Images