JP2013243605A - Communication device and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize effective utilization of a resource.SOLUTION: In a base station 10, a scheduler 15 selects a TA (Timing Advance) value from candidate TA values for controlling transmission timing on the basis of reception timing and target timing of a reference signal. Also, a conversion unit 16 converts transmission data that is different from the selected TA value into a TA value included in the candidate TA values. Then, a transmission processing unit 17 transmits the control value selected by the scheduler 15 to a mobile station 20 in a moving mode, and transmits the control value acquired by the conversion unit 16 to the mobile station 20 in a stationary mode instead of the control value selected by the scheduler 15.

Description

  The present invention relates to a communication device and a communication method.

  In 3GPP LTE (3rd Generation Partnership Project Radio Access Network Long Term Evolution), OFDMA (Orthogonal Frequency Division Multiple Access) is adopted as a communication scheme for downlink, SC-FDMA (Single Carrier Frequency Division Multiple Access as an uplink communication system ) Is adopted. 3GPP LTE is sometimes simply referred to as “LTE” in the following.

  In the LTE system, a base station (evolved Node B: eNB) controls transmission timing of RS (Reference Signal) by a mobile station (User Equipment: UE). Specifically, the base station monitors the reception timing of an SRS (Sounding Reference Signal) transmitted from a mobile station whose transmission timing is to be controlled. Then, the base station transmits a timing control signal (that is, a TA (Timing Advance) signal) including a control value (that is, a TA (Timing Advance) value) corresponding to the difference between the reception timing and the target timing to the mobile station. . Then, the mobile station adjusts the RS transmission timing based on the received timing control signal. Here, the mobile station with a longer separation distance from the base station will advance the RS transmission timing. That is, the TA value is a value that depends on the separation distance between the mobile station that is the transmission timing control target and the base station.

  Further, the TA signal is used for updating the Time Alignment Timer in the mobile station. That is, in the 3GPP system, when the Time Alignment Timer expires, the mobile station releases PUCCH (Physical Uplink Control Channel) and SRS uplink resources. Accordingly, when it is desired to maintain uplink resources between the base station and the mobile station, the TA signal is periodically transmitted.

JP 2011-199356 A

  By the way, as described above, the TA value depends on the distance between the base station and the mobile station whose transmission timing is to be controlled, so it does not change when the mobile station is stationary, and ideally the same value. It becomes. Therefore, continuing to transmit the TA signal when the mobile station is stationary is a waste of resources.

  On the other hand, if the TA signal is not transmitted, waste of resources can be eliminated. However, as described above, since the TA signal has a function of updating the Time Alignment Timer, it is transmitted at a predetermined cycle.

  The disclosed technology has been made in view of the above, and an object thereof is to provide a communication device and a communication method that realize effective use of resources.

  According to an aspect of the disclosure, a communication device that controls transmission timing of a reference signal in another communication device, the control value for controlling the transmission timing based on reception timing and target timing of the reference signal in its own device In the selection mode for selecting a control value from the candidate group, the conversion unit for converting transmission data other than the control value to the control value in the candidate group, and the movement mode of the other communication device, the selection is performed. A transmission processing unit that transmits the control value obtained by the conversion unit to the other communication device instead of the selected control value in the stationary mode. It comprises.

  According to the disclosed aspect, effective use of resources can be realized.

FIG. 1 is a block diagram illustrating an example of a base station according to the first embodiment. FIG. 2 is a diagram illustrating an example of the conversion table. FIG. 3 is a block diagram illustrating an example of a mobile station according to the first embodiment. FIG. 4 is a block diagram illustrating an example of a mobile station according to the second embodiment. FIG. 5 is a block diagram illustrating an example of a base station according to the second embodiment. FIG. 6 is a diagram for explaining the reference timing adjustment. FIG. 7 is a diagram illustrating a hardware configuration of the base station. FIG. 8 is a diagram illustrating a hardware configuration of the mobile station.

  Hereinafter, embodiments of a communication device and a communication method disclosed in the present application will be described in detail with reference to the drawings. Note that the communication device and the communication method disclosed in the present application are not limited by this embodiment. Moreover, the same code | symbol is attached | subjected to the structure which has the same function in embodiment, and the overlapping description is abbreviate | omitted.

[Example 1]
[Base station configuration]
FIG. 1 is a block diagram illustrating an example of a base station according to the first embodiment. In FIG. 1, a base station 10 includes an RF (Radio Frequency) receiving unit 11, a reception processing unit 12, a determination information acquisition unit 13, an RS acquisition unit 14, a scheduler 15, a conversion unit 16, and a transmission processing unit. 17 and an RF transmitter 18.

  The RF receiving unit 11 receives a radio signal transmitted from the mobile station 20 described later, and obtains a baseband signal by performing radio processing such as down-conversion on the received radio signal.

  The reception processing unit 12 performs demodulation processing on the baseband signal obtained in the RF reception unit 11 and outputs the obtained reception signal.

  The determination information acquisition unit 13 acquires stillness determination information from the reception signal obtained by the reception processing unit 12 and outputs the acquired stillness determination information to the scheduler 15. The stationary determination information is information transmitted from the mobile station 20 when the later-described mobile station 20 is in a stationary state without moving.

  The RS acquisition unit 14 acquires an RS signal from the reception signal obtained by the reception processing unit 12, and outputs the acquired RS signal and information regarding the reception timing of the RS signal to the scheduler 15.

  When the scheduler 15 receives the stationary determination information from the determination information acquisition unit 13, the scheduler 15 enters the “stationary mode” with the mobile station 20 described later, and in the state where the stationary determination information is not received from the determination information acquisition unit 13, the “movement mode” "

  Then, in the movement mode, the scheduler 15 determines the TA value based on the information regarding the reception timing of the RS signal received from the RS acquisition unit 14, and outputs the determined TA value to the transmission processing unit 17. Specifically, in the movement mode, the scheduler 15 selects a TA value candidate corresponding to the difference between the reception timing indicated by the information related to the reception timing of the RS signal and the target timing from the TA value candidate group as the TA value. . The selected TA value is output to the transmission processing unit 17.

  Further, the scheduler 15 outputs a “conversion instruction signal” to the conversion unit 16 in the still mode.

  When receiving the conversion instruction signal from the scheduler 15, that is, in the still mode, the conversion unit 16 converts the input transmission data into a TA value based on the conversion table. The TA value obtained by converting the transmission data is output to the transmission processing unit 17. Specifically, the conversion table is stored in a memory (not shown) included in the conversion unit 16. In the conversion table, the above-described TA value candidate group is associated with the bit pattern corresponding to each TA value candidate. FIG. 2 is a diagram illustrating an example of the conversion table. Then, the conversion unit 16 replaces each bit string of the processing target unit included in the input transmission data string with a TA value candidate associated with the same bit pattern as the pattern of each bit string in the correspondence table.

  The transmission processing unit 17 maps the TA signal including the TA value received from the scheduler 15 or the conversion unit 16 to a resource allocated for transmission of the TA signal, and forms a transmission signal.

  The RF transmission unit 18 performs radio processing such as up-conversion on the transmission signal formed by the transmission processing unit 17 to form a radio signal and transmits it to the mobile station 20 described later.

[Configuration of mobile station]
FIG. 3 is a block diagram illustrating an example of a mobile station according to the first embodiment. In FIG. 3, the mobile station 20 includes an RF reception unit 21, a reception processing unit 22, a conversion unit 23, an acquisition unit 24, a control unit 25, an RS generation unit 26, a transmission processing unit 27, and a stationary determination. Unit 28 and an RF transmission unit 29.

  The RF receiver 21 receives a radio signal transmitted from the base station 10 and performs a radio process such as down-conversion on the received radio signal to obtain a baseband signal.

  The reception processing unit 22 performs demodulation processing on the baseband signal obtained by the RF reception unit 21 and outputs the obtained reception signal.

  When receiving the stillness determination information from the stillness determination unit 28, the conversion unit 23 enters the “still mode”, and when not receiving the stillness determination information from the stillness determination unit 28, the conversion unit 23 enters the “movement mode”.

  Then, in the still mode, the conversion unit 23 converts the TA signal included in the reception signal output from the reception processing unit 22 into reception data based on the conversion table. Specifically, the conversion table is the same as that of the base station 10 and is stored in a memory (not shown) included in the conversion unit 23. Then, the conversion unit 23 replaces the TA value candidate having the same value as the TA value included in the TA signal with a bit pattern associated with the correspondence table. Note that the conversion unit 23 does not operate in the movement mode.

  The acquisition unit 24 becomes “still mode” when receiving the stillness determination information from the stillness determination unit 28, and enters “movement mode” when no stillness determination information is received from the stillness determination unit 28.

  Then, the acquisition unit 24 acquires the TA signal included in the reception signal output from the reception processing unit 22 and outputs the TA signal to the control unit 25 in the movement mode. Note that the acquisition unit 24 may not operate when no TA signal is transmitted in the still mode. In addition, even when the TA signal including the original TA value is transmitted less frequently than in the movement mode even in the stationary mode, the acquisition unit 24 may acquire the TA signal at that timing and output the TA signal to the control unit 25. Good.

  The control unit 25 generates a timing shift instruction corresponding to the TA value included in the TA signal received from the acquisition unit 24 and outputs the timing shift instruction to the transmission processing unit 27. Thereby, the RS transmission timing in the transmission processing unit 27 is controlled.

  The RS generation unit 26 generates an RS and outputs it to the transmission processing unit 27.

  The stationary determination unit 28 determines whether or not the own device is stationary based on the position information of the own device acquired by a GPS receiving unit (not shown). If the stillness determination unit 28 determines that it is still, it generates stillness determination information and outputs it to the conversion unit 23, the acquisition unit 24, and the transmission processing unit 27.

  The transmission processing unit 27 generates a transmission signal including stillness determination information received from the stillness determination unit 28 and outputs the transmission signal to the RF transmission unit 29. In addition, the transmission processing unit 27 generates a transmission signal included in the time resource, that is, a timing in which the RS received from the RS generation unit 26 is shifted from the reference timing by the time indicated by the timing shift instruction received from the control unit 25. To the unit 29. Thereby, RS will be transmitted at the timing according to TA value.

  The RF transmission unit 29 forms a radio signal by performing radio processing such as up-conversion on the transmission signal formed by the transmission processing unit 17 and transmits the radio signal to the base station 10.

[Operation of base station and mobile station]
Operations of the base station 10 and the mobile station 20 having the above configuration will be described.

  As described above, the processing operations in the base station 10 and the mobile station 20 are different between the movement mode and the stationary mode. When receiving the stationary determination information from the mobile station 20, the base station 10 switches from the moving mode to the stationary mode. In addition, when the stationary determination unit 28 determines that the mobile station 20 is stationary, the mobile station 20 switches from the movement mode to the stationary mode.

<Move mode>
In the base station 10, in the mobile mode, the scheduler 15 determines the TA value based on the information regarding the reception timing of the RS signal received from the RS acquisition unit 14, and outputs the determined TA value to the transmission processing unit 17. .

  The transmission processing unit 17 maps the TA signal including the TA value received from the scheduler 15 to the resource allocated to the TA signal transmission, and forms a transmission signal.

  This transmission signal is transmitted to the mobile station 20 via the RF transmission unit 18 and the antenna.

  In the mobile station 20, the acquisition unit 24 acquires a TA signal included in the reception signal output from the reception processing unit 22 and outputs the TA signal to the control unit 25.

  The control unit 25 generates a timing shift instruction corresponding to the TA value included in the TA signal received from the acquisition unit 24 and outputs the timing shift instruction to the transmission processing unit 27.

  The transmission processing unit 27 generates a transmission signal included in a time resource, that is, a timing at which the RS received from the RS generation unit 26 is shifted from the reference timing by the time indicated by the timing shift instruction received from the control unit 25.

  This transmission signal is transmitted to the base station 10 via the RF transmission unit 29 and the antenna.

<Still mode>
In the base station 10, the scheduler 15 outputs a “conversion instruction signal” to the conversion unit 16.

  The conversion unit 16 replaces each bit string of the processing target unit included in the input transmission data string with a TA value candidate associated with the same bit pattern as the pattern of each bit string in the correspondence table (see FIG. 2). .

  Specifically, it is assumed that the transmission data string is “100101011110111011011...” And the length of the processing target unit is 3 bits.

  In this case, the transmission data string described above can be divided into bit strings of processing target units such as “100” “101” “011” “110” “111” “011” “011”.

  Then, when each bit string of the processing target unit is converted using the correspondence table of FIG. 2, “0 × 20” “0 × 21” “0 × 1E” “0 × 22” “0 × 23” “0 × 1E” The TA value candidate string is “0 × 1E”.

  Then, the transmission processing unit 17 maps the TA signal including the TA value received from the conversion unit 16 to a resource allocated for transmission of the TA signal, and forms a transmission signal.

  This transmission signal is transmitted to the mobile station 20 via the RF transmission unit 18 and the antenna.

  In the mobile station 20, the conversion unit 23 replaces the TA value candidate having the same value as the TA value included in the received TA signal with the bit pattern associated with the correspondence table (see FIG. 2).

  That is, here, a TA value sequence of “0 × 20”, “0 × 21”, “0 × 1E”, “0 × 22”, “0 × 23”, “0 × 1E”, “0 × 1E”,. The

  Therefore, when this TA value sequence is converted using the correspondence table of FIG. 2, a data sequence “100101011110111011011...” Is obtained.

  As described above, according to the present embodiment, in the base station 10, the scheduler 15 selects a TA value from a candidate group of TA values for controlling the transmission timing based on the reception timing and the target timing of the reference signal. To do. Further, the conversion unit 16 converts transmission data other than the TA value into a TA value in the TA value candidate group. The transmission processing unit 17 transmits the control value selected by the scheduler 15 to the mobile station 20 in the mobile mode, and is obtained by the conversion unit 16 instead of the control value selected by the scheduler 15 in the stationary mode. The control value is transmitted to the mobile station 20.

  In the mobile station 20, the reception processing unit 22 receives a signal including a TA value for RS transmission timing. And the control part 25 adjusts the transmission timing of RS based on TA value contained in the signal received by the reception process part 22 in movement mode. Then, the conversion unit 23 converts the control value included in the signal received by the reception processing unit 22 into a bit pattern in the still mode.

  By doing so, other transmission data can be transmitted using the TA value in the static mode in which the TA value does not change, so that effective use of resources can be realized.

[Example 2]
In the second embodiment, in the stationary mode, the mobile station superimposes transmission data on the RS transmission timing.

[Configuration of mobile station]
FIG. 4 is a block diagram illustrating an example of a mobile station according to the second embodiment. In FIG. 4, the mobile station 30 includes an RF receiving unit 31, a reception processing unit 32, an acquisition unit 33, a control unit 34, an RS generation unit 35, a transmission processing unit 36, a stationary determination unit 37, an RF And a transmission unit 38.

  The RF receiver 31 receives a radio signal transmitted from a base station 40 described later, and performs a radio process such as down-conversion on the received radio signal to obtain a baseband signal.

  The reception processing unit 32 performs demodulation processing on the baseband signal obtained by the RF reception unit 31 and outputs the obtained reception signal.

  The acquisition unit 33 acquires the TA signal included in the reception signal output from the reception processing unit 32 and outputs the TA signal to the control unit 25.

  When receiving the stillness determination information from the stillness determination unit 37, the control unit 34 enters “still mode”, and when not receiving the stillness determination information from the stillness determination unit 37, the control unit 34 enters “movement mode”.

  In the movement mode, the control unit 34 generates a timing shift instruction corresponding to the TA value included in the TA signal received from the acquisition unit 33 and outputs the timing shift instruction to the transmission processing unit 36.

  On the other hand, in the still mode, the control unit 34 generates a timing shift instruction according to the transmission data and outputs the timing shift instruction to the transmission processing unit 36. Specifically, in the stationary mode, the control unit 34 uses a correspondence table (see FIG. 2) for each bit string of the processing target unit included in the input transmission data string with respect to the same bit pattern as the pattern of each bit string. Replace with the associated TA value candidate. Then, the control unit 34 generates a timing shift instruction corresponding to the TA value candidate obtained by the replacement, and outputs it to the transmission processing unit 36. As a result, the transmission data is superimposed on the transmission timing.

  The RS generation unit 35 generates an RS and outputs the RS to the transmission processing unit 36.

  The transmission processing unit 36 generates a transmission signal including stillness determination information received from the stillness determination unit 37 and outputs the transmission signal to the RF transmission unit 38. Further, the transmission processing unit 36 generates a transmission signal included in the time resource, that is, a timing in which the RS received from the RS generation unit 35 is shifted from the reference timing by the time indicated by the timing shift instruction received from the control unit 34, that is, RF transmission. To the unit 38. Thereby, RS will be transmitted at the timing according to TA value.

  The stationary determination unit 37 determines whether or not the own device is stationary based on the position information of the own device acquired by a GPS receiving unit (not shown). And when it determines with the still determination part 37 being still, still determination information is produced | generated and it outputs to the control part 34 and the transmission process part 36. FIG.

  The RF transmission unit 38 forms a radio signal by performing radio processing such as up-conversion on the transmission signal formed by the transmission processing unit 36, and transmits the radio signal to the base station 40 described later.

[Base station configuration]
FIG. 5 is a block diagram illustrating an example of a base station according to the second embodiment. In FIG. 5, the base station 40 includes an RF reception unit 41, a reception processing unit 42, a determination information acquisition unit 43, an RS acquisition unit 44, a scheduler 45, a conversion unit 46, a transmission processing unit 47, an RF And a transmission unit 48.

  The RF receiving unit 41 receives a radio signal transmitted from the mobile station 30, and performs a radio process such as down-conversion on the received radio signal to obtain a baseband signal.

  The reception processing unit 42 performs demodulation processing on the baseband signal obtained by the RF reception unit 41 and outputs the obtained reception signal.

  The determination information acquisition unit 43 acquires stillness determination information from the reception signal obtained by the reception processing unit 42 and outputs the acquired stillness determination information to the scheduler 45 and the conversion unit 46.

  The RS acquisition unit 44 acquires an RS signal from the reception signal obtained by the reception processing unit 42, and outputs the acquired RS signal and information regarding the reception timing of the RS signal to the scheduler 45 and the conversion unit 46.

  When the scheduler 45 receives the stationary determination information from the determination information acquisition unit 43, the scheduler 45 becomes “stationary mode” with the mobile station 30, and when the stationary determination information is not received from the determination information acquisition unit 43, the scheduler 45 becomes “movement mode”. Become.

  In the movement mode, the scheduler 45 determines the TA value based on the information regarding the reception timing of the RS signal received from the RS acquisition unit 44, and outputs the determined TA value to the transmission processing unit 47. Specifically, in the movement mode, the scheduler 45 selects, as a TA value, a TA value candidate corresponding to the difference between the reception timing indicated by the information related to the reception timing of the RS signal and the target timing from the TA value candidate group. . The selected TA value is output to the transmission processing unit 47. Note that the scheduler 45 may not perform the TA value selection operation when no TA signal is transmitted in the still mode. In addition, when the TA signal including the original TA value is transmitted less frequently than in the movement mode even in the stationary mode, the scheduler 45 may perform the TA value selection operation at that timing.

  When the conversion unit 46 receives the stillness determination information from the determination information acquisition unit 43, the conversion unit 46 becomes “still mode”, and when the stillness determination information is not received from the determination information acquisition unit 43, the conversion unit 46 becomes “movement mode”.

  And the conversion part 46 converts the information regarding the reception timing of RS signal received from the RS acquisition part 44 into reception data based on a conversion table in still mode. Specifically, the conversion unit 46 reads information regarding the reception timing of the RS signal into a bit pattern associated with the TA value candidate having the same value as the TA value according to the reception timing of the RS signal in the correspondence table. . Note that the converter 46 does not operate in the movement mode.

  The transmission processing unit 47 maps the TA signal including the TA value received from the scheduler 45 to the resource allocated to the TA signal transmission, and forms a transmission signal.

  The RF transmission unit 48 forms a radio signal by performing radio processing such as up-conversion on the transmission signal formed by the transmission processing unit 47 and transmits the radio signal to the mobile station 30.

[Operation of base station and mobile station]
Operations of the mobile station 30 and the base station 40 having the above configuration will be described.

  As described above, the processing operations in the mobile station 30 and the base station 40 differ between the movement mode and the stationary mode. When receiving the stationary determination information from the mobile station 30, the base station 40 switches from the moving mode to the stationary mode. In addition, when the stationary determination unit 37 determines that the mobile station 30 is stationary, the mobile station 30 switches from the movement mode to the stationary mode.

<Move mode>
In the base station 40, in the mobile mode, the scheduler 45 determines the TA value based on the information regarding the reception timing of the RS signal received from the RS acquisition unit 44, and outputs the determined TA value to the transmission processing unit 47. .

  The transmission processing unit 47 maps the TA signal including the TA value received from the scheduler 45 to the resource allocated to the TA signal transmission, and forms a transmission signal.

  This transmission signal is transmitted to the mobile station 30 via the RF transmission unit 48 and the antenna.

  In the mobile station 30, the acquisition unit 33 acquires a TA signal included in the reception signal output from the reception processing unit 32 and outputs the TA signal to the control unit 34.

  The control unit 34 generates a timing shift instruction corresponding to the TA value included in the TA signal received from the acquisition unit 33 and outputs the timing shift instruction to the transmission processing unit 36.

  The transmission processing unit 36 generates a transmission signal included in the time resource, that is, a timing shifted from the first reference timing by the time indicated by the timing shift instruction received from the control unit 34 for the RS received from the RS generation unit 35.

  This transmission signal is transmitted to the base station 40 via the RF transmission unit 38 and the antenna.

<Still mode>
In the mobile station 30, the control unit 34 associates each bit string of the processing target unit included in the input transmission data string with the same bit pattern as the pattern of each bit string in the correspondence table (see FIG. 2). Read as TA value candidate.

  Specifically, it is assumed that the transmission data string is “100101011110111011011...” And the length of the processing target unit is 3 bits.

  In this case, the transmission data string described above can be divided into bit strings of processing target units such as “100” “101” “011” “110” “111” “011” “011”.

  Then, when each bit string of the processing target unit is converted using the correspondence table of FIG. 2, “0 × 20” “0 × 21” “0 × 1E” “0 × 22” “0 × 23” “0 × 1E” The TA value candidate string is “0 × 1E”.

  Here, in FIG. 2, “0 × 1E”, “0 × 1D”, “0 × 1C”, and “0 × 1B” correspond to the timing earlier by 0.5 μsec with “0 × 1F” as a reference. It is attached. On the other hand, “0 × 20”, “0 × 21”, “0 × 22”, and “0 × 23” are respectively associated with timings delayed by 0.5 μsec with “0 × 1F” as a reference. The timing corresponding to “0 × 1F” is matched with the second reference timing.

  Then, the control unit 34 selects a TA value candidate string of “0 × 20”, “0 × 21”, “0 × 1E”, “0 × 22”, “0 × 23”, “0 × 1E”, “0 × 1E”,. A timing shift instruction corresponding to the timing is generated. That is, the control unit 34 first generates a timing shift instruction corresponding to a timing that is 0.5 μsec later than the second reference timing in accordance with “0 × 20”. Next, in accordance with “0 × 21”, the control unit 34 generates a timing shift instruction corresponding to a timing that is 1.0 μsec later than the second reference timing. Similarly, timing shift instructions are sequentially generated.

  Then, the transmission processing unit 36 generates a transmission signal included in the time resource, that is, a timing at which the RS received from the RS generation unit 35 is shifted from the second reference timing by the time indicated by the timing shift instruction received from the control unit 34. .

  This transmission signal is transmitted to the base station 40 via the RF transmission unit 38 and the antenna.

  In the base station 40, the conversion unit 46 reads the information regarding the reception timing of the RS signal into a bit pattern associated with the TA value candidate having the same value as the TA value according to the reception timing of the RS signal in the correspondence table. .

  That is, here, the RS is a TA value sequence of “0 × 20”, “0 × 21”, “0 × 1E”, “0 × 22”, “0 × 23”, “0 × 1E”, “0 × 1E”,. Are received at a reception timing group corresponding to the.

  Therefore, when this TA value sequence is converted using the correspondence table of FIG. 2, a data sequence “100101011110111011011...” Is obtained.

  Note that the second reference timing can be adjusted as follows. FIG. 6 is a diagram for explaining the reference timing adjustment. That is, in the stationary mode, before superimposing transmission data on the RS signal transmission timing, gradually change the transmission timing, identify the boundary where the TA value changes, and adjust the reference timing based on the identified boundary Is preferred. Specifically, in FIG. 6, the transmission timing is shifted by 0.2 μsec. The TA value is “0 × 1F” from the first time to the third time, and is changed to “0 × 1E” at the fourth time. At this time, the TA boundary can be specified between the third transmission timing and the fourth transmission timing. The reference timing is preferably set at the center between adjacent TA boundaries. That is, 1TA is 0.5 μsec as described above. Therefore, it is preferable to set the timing that is offset by 0.25 (= 0.5 / 2) μsec from the specified TA boundary as the reference timing.

  As described above, according to the present embodiment, in the mobile station 30, the reception processing unit 32 receives a signal including a TA value regarding the transmission timing of the RS. And the transmission process part 36 transmits RS with the transmission timing according to TA value in movement mode, and transmits RS with the transmission timing according to the bit pattern of transmission data other than RS in static mode.

  In the base station 40, the scheduler 45 selects a TA value from a candidate group of TA values for controlling the transmission timing based on the RS reception timing and the target timing in the own device in the mobile mode. Then, the transmission processing unit 47 transmits the TA value selected by the scheduler 45 to the mobile station 30. The conversion unit 46 converts the RS reception timing into a bit pattern in the still mode.

  By doing so, other transmission data can be transmitted using the RS transmission timing in the static mode in which the TA value does not change, so that effective use of resources can be realized.

[Example 3]
In the first and second embodiments, the content of transmission data superimposed on the TA value or SR transmission timing in the still mode is not particularly limited. In contrast, in the third embodiment, a case will be described in which transmission data is data on control information, particularly quality information.

  First, the base station 10 described in the first embodiment replaces uplink quality information with TA values in the stationary mode. The uplink quality information may be information related to the error rate of the uplink data, or may be information related to the reception quality of the RS signal transmitted from the mobile station 20.

  Then, the mobile station 20 can specify the quality information of the uplink by rereading the received TA value. The mobile station 20 can simplify the baseband processing when the uplink quality is higher than a predetermined level, that is, when the quality is good. For example, the mobile station 20 may reduce the search range of the RS signal transmitted from the mobile station 20, may reduce the transmission frequency of the RS signal, and may simplify the channel estimation method.

  In addition, in the stationary mode, the mobile station 30 described in the second embodiment replaces downlink quality information with a TA value, and transmits an RS signal at a transmission timing corresponding to the TA value. The downlink quality information may be information related to the error rate of the downlink data, or may be information related to the reception quality of the RS signal when the RS signal is transmitted from the base station 40.

  Then, the base station 40 can specify the quality information of the uplink by rereading the reception timing of the RS signal. The base station 40 can simplify the baseband processing when the downlink quality is higher than a predetermined level, that is, when the quality is good. For example, the base station 40 may reduce the search range of the RS signal transmitted from the base station 40, may reduce the transmission frequency of the RS signal, or may simplify the channel estimation method.

  As described above, by transmitting the quality information using the TA value or the RS transmission timing in the still mode, it is possible to reduce the load on the baseband processing, and as a result, it is possible to reduce power consumption.

[Other embodiments]
[1] In the third embodiment, the case where the transmission data is control information has been described. However, the present invention is not limited to this. That is, the transmission data may be user data, or data regarding traffic information, failure information, or load information.

  Further, the transmission data may be switched between data about control information and user data. In particular, when transmission data is transmitted from the base station 10 to the mobile station 20 using the TA value, a predetermined format can be used. In the predetermined format, identification information indicating whether the transmission data is control information or user data is included in the first area H1 of the header portion. And the information regarding data length is included in the 2nd field H2 of a header part. The data part includes data of a type corresponding to the identification information included in the first area H1 of the header part.

  In addition, the cause of switching to user data may be a user service contract, an instruction from an upper layer, or a packet type.

  [2] In each of the above embodiments, the description has been given on the assumption that the mobile station uses the GPS function to determine that the mobile station is stationary and notifies the base station of the determination result. However, the present invention is not limited to this. For example, the base station determines whether the mobile station is stationary based on a change in the reception timing of the RS signal, that is, a change in the TA value for the mobile station, and notifies the mobile station of the determination result. Also good. Further, the base station may determine whether or not the mobile station is stationary based on the Doppler frequency of the mobile station and notify the determination result to the mobile station.

  [3] The base station and mobile station of each of the above embodiments can be realized by the following hardware configuration. Since the pair of base station 40 and mobile station 30 can be considered in the same manner as base station 10 and mobile station 20, the base station 10 and mobile station 20 will be described as an example.

  FIG. 7 is a diagram illustrating a hardware configuration of the base station. As shown in FIG. 7, the base station 10 includes, as hardware components, a DSP (Digital Signal Processor) 10a, a memory 10b, an RF (Radio Frequency) circuit 10c, and a network IF (Inter Face) 10d. Have. The RF circuit 10c has an antenna. The memory 10b includes, for example, a RAM such as a SDRAM (Synchronous Dynamic Random Access Memory), a ROM (Read Only Memory), and a flash memory. The reception processing unit 12, the determination information acquisition unit 13, the RS acquisition unit 14, the scheduler 15, the conversion unit 16, and the transmission processing unit 17 are realized by an integrated circuit such as a DSP 10a. The RF receiving unit 11 and the RF transmitting unit 18 are realized by the RF circuit 10c.

  FIG. 8 is a diagram illustrating a hardware configuration of the mobile station. As shown in FIG. 8, in terms of hardware, the mobile station 20 includes a CPU (Central Processing Unit) 20a, a memory 20b, an RF circuit 20c having an antenna, and a display device 20d such as an LCD (Liquid Crystal Display). And have. The memory 20b is composed of, for example, a RAM such as an SDRAM, a ROM, and a flash memory. The RF receiving unit 21 and the RF transmitting unit 29 are realized by the RF circuit 20c. The reception processing unit 22, the conversion unit 23, the acquisition unit 24, the control unit 25, the RS generation unit 26, the transmission processing unit 27, and the stillness determination unit 28 are realized by an integrated circuit such as a CPU 20a. May be. The reception processing unit 22, the conversion unit 23, the acquisition unit 24, the control unit 25, the RS generation unit 26, the transmission processing unit 27, and the stillness determination unit 28 are a baseband CPU, an application CPU, or the like. It may be divided into a plurality of CPUs and mounted. When the mobile station 20 is a mobile phone, a voice input / output unit connected to a microphone and a speaker, an input unit such as an operation key, and the like may be mounted.

  The various processes described in the above embodiments can be realized by executing a prepared program on a computer. That is, a program corresponding to each process executed by the reception processing unit 12, the determination information acquisition unit 13, the RS acquisition unit 14, the scheduler 15, the conversion unit 16, and the transmission processing unit 17 is recorded in the memory 10b. Each program may be read by the DSP 10a to function as a process. A program corresponding to each process executed by the reception processing unit 22, the conversion unit 23, the acquisition unit 24, the control unit 25, the RS generation unit 26, the transmission processing unit 27, and the stillness determination unit 28. May be recorded in the memory 20b, and each program may be read by the CPU 20a to function as a process.

  [4] In each of the above embodiments, the base station and the mobile station have been described as examples. However, the present invention is not limited to this, and the above-described embodiment also holds true for a communication device and a communication device that receives a reference signal transmitted from the communication device.

10, 40 Base station 11, 21, 31, 41 RF reception unit 12, 22, 32, 42 Reception processing unit 13, 43 Determination information acquisition unit 14, 44 RS acquisition unit 15, 45 Scheduler 16, 23, 46 Conversion unit 17 , 27, 36, 47 Transmission processing unit 18, 29, 38, 48 RF transmission unit 20, 30 Mobile station 24, 33 Acquisition unit 25, 34 Control unit 26, 35 RS generation unit 28, 37 Stationary determination unit

Claims (8)

A communication device that controls transmission timing of a reference signal in another communication device,
A selection unit that selects a control value from a group of control value candidates for controlling the transmission timing based on the reception timing and the target timing of the reference signal in its own device;
A conversion unit that converts transmission data other than the control value into a control value in the candidate group;
In the movement mode of the other communication device, the selected control value is transmitted to the other communication device, and in the stationary mode, the control value obtained by the converter is used instead of the selected control value. A transmission processing unit for transmitting to the other communication device;
A communication apparatus comprising: A storage unit for storing a correspondence relationship between the candidate group and a bit pattern corresponding to each candidate;
The conversion unit converts the transmission data into a control value associated with the bit pattern of the transmission data in the correspondence relationship.
The communication apparatus according to claim 1. A receiver that receives a signal including a control value for the transmission timing of the reference signal;
An adjustment unit that adjusts the transmission timing of the reference signal based on a control value included in the received signal in the movement mode of the device itself;
A conversion unit that converts a control value included in the received signal into a bit pattern in a stationary mode of the device;
A communication apparatus comprising: A storage unit that stores a correspondence relationship between the control value candidate group and a bit pattern corresponding to each candidate;
The converter converts the control value included in the received signal into a bit pattern associated with the correspondence relationship;
The communication apparatus according to claim 3. Based on the reference signal reception timing and the target timing in the first communication device, select a control value from a group of control value candidates for controlling the transmission timing of the reference signal in the second communication device,
Converting transmission data other than the control value into a control value in the candidate group;
In the movement mode of the second communication device, the selected control value is transmitted to the second communication device, and in the stationary mode, the control value obtained by the conversion instead of the selected control value. To the second communication device,
A communication method characterized by the above. Receive a signal containing the control value for the transmission timing of the reference signal,
In the movement mode, based on a control value included in the received signal, adjust the transmission timing of the reference signal,
In the still mode, the control value included in the received signal is converted into a bit pattern.
A communication method characterized by the above. A receiver that receives a signal including a control value for the transmission timing of the reference signal;
In the movement mode of the own apparatus, the reference signal is transmitted at a transmission timing according to the control value, and in the stationary mode, the reference signal is transmitted at a transmission timing according to a bit pattern of transmission data other than the reference signal. A processing unit;
A communication apparatus comprising: A communication device that controls transmission timing of a reference signal in another communication device,
In the movement mode of the other communication device, a selection unit that selects a control value from a group of control value candidates for controlling the transmission timing based on the reception timing and the target timing of the reference signal in its own device;
A transmission processing unit for transmitting the selected control value to the other communication device;
A conversion unit that converts the reception timing into a bit pattern in the still mode of the other communication device;
A communication apparatus comprising:

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