JP2000324528A - Mobile station device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the constitution of the mobile station device which establishes synchronism with a base station device according to a pilot symbol signal sent by radio from the base station device at prescribed intervals of time. SOLUTION: The mobile station device is equipped with antennas 1a and 1b which receive a signal transmitted by radio from for example, the base station device and also equipped with synchronism establishing means (matched filters 5a and 5b and profile parts 6a and 6b) which establish synchronism with the base station device according to the pilot signals received from the station device with the antennas and when a composing means 8 puts together signals of the same information obtained with those antennas and synchronism establishing means, a control means uses at least one of the synchronism establishing means on a time-division basis at the time of a hand-over between at least different base station devices to establish synchronism with those base station devices.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile station apparatus (for example, an MS) that establishes synchronization with a base station apparatus based on a pilot symbol signal wirelessly transmitted from the base station apparatus (for example, a BTS). The present invention relates to a mobile station device that achieves synchronization with a plurality of base station devices during a handover with a simple configuration.

[0002]

2. Description of the Related Art For example, CDMA (Code Division Multip
le Access) system is known as a multiple access system using a spread spectrum communication system.
In a mobile communication system adopting the scheme, studies are being made on performing diversity handover (DHO).

First, the operation at the time of DHO will be described. When the mobile station apparatus performs DHO, the mobile station apparatus receives a radio frame of a perch channel (perch Ch) when wirelessly transmitted from the DHO destination base station apparatus (DHO destination BTS).
FIG. 3A shows a configuration example of a radio frame (for example, a frame having a length of 10 ms) of a perch channel wirelessly transmitted in downlink communication from the base station device to the mobile station device. As shown in FIG. 3A, the radio frame of the perch channel transmitted from the base station apparatus has a plurality of slots (for example, 16 slots # 1 to # 16).
It is composed of

Further, as shown in FIG. 1B, each slot has a plurality of symbols (for example, 10 symbols # 1).
To # 10), and a symbol called a pilot symbol is arranged in the first few symbols of each slot. Note that the pilot symbols are used to establish synchronization between the base station device and the mobile station device, as described later. One symbol at the end of each slot is used as a long code mask symbol, and is spread with, for example, a common short code.

When performing DHO, the mobile station apparatus transmits a radio frame of the uplink dedicated physical channel (uplink dedicated physical channel) currently being transmitted in uplink communication to the base station apparatus and the DHO destination BT.
It is necessary to measure the time difference from the perch channel radio frame from S and, as described below, based on the perch channel (DHO destination perch channel) radio frame from the DHO destination BTS, Must be synchronized.

[0006] Specifically, the mobile station device receives the received DH.
The O perch channel is despread with a long code to obtain a correlation. The long code used at this time is broadcast from the DHO source base station apparatus (DHO source BTS), and its phase is the same as the phase of the DHO destination perch channel. Upon establishing synchronization with the radio frame of the DHO destination perch channel, the mobile station device measures the time difference between the radio frame of the DHO destination perch channel and the radio frame of the same frame number of the uplink dedicated physical channel being transmitted,
The measured time difference (measured frame time difference) is DHO source B
Notify the DHO destination BTS via the TS.

[0007] Based on the notified time difference, the DHO destination BTS sends the downlink dedicated physical channel to the mobile station apparatus so that the transmission timing is the same as the transmission timing of the radio frame of the downlink dedicated physical channel from the DHO source BTS. Transmit a radio frame. The mobile station equipment is the DHO destination BTS
Receive a downlink dedicated physical channel radio frame from
Establish chip synchronization. When the mobile station apparatus establishes chip synchronization, it starts maximum ratio combining processing on the radio frame of the downlink dedicated physical channel received from the DHO destination BTS.

Here, FIG. 4A shows an example of the reception timing of a radio frame of the perch channel of the DHO destination received by the mobile station apparatus, and FIG. 4B shows the timing of transmission from the mobile station apparatus. FIG. 3C shows an example of the transmission timing of the radio frame of the uplink dedicated physical channel, and FIG. 3C shows the DHO source BTS received by the mobile station apparatus.
FIG. 4D shows an example of the reception timing of the radio frame of the downlink dedicated physical channel from DHO.
3 shows an example of reception timing of a radio frame of a downlink dedicated physical channel transmitted from a TS by a mobile station device. In addition, in FIGS. 6A to 6D, as an example,
The figure shows a radio frame whose frame number is “2 ¹⁶ −1”, “0”, or “1”, and also shows a case where the measured frame time difference T is “1280 chips”.

FIG. 5 shows an example of a procedure of processing performed by the mobile station apparatus, the DHO source BTS, and the DHO destination BTS at the time of DHO. As shown in the figure, first, the mobile station apparatus communicates with the DHO source BTS during the DHO.
The radio frame of the uplink dedicated physical channel is transmitted to the source BTS, and when the radio frame of the perch channel is received from the DHO destination BTS, the measured frame time difference is notified to the DHO source BTS, and as shown below. Then, a process of establishing synchronization with the DHO destination BTS is started.

[0010] That is, the DHO source BTS notifies the DHO destination BTS of the frame time difference measurement value notified from the mobile station device via, for example, a line, and the DHO destination BTS moves at the transmission timing based on the notified frame time difference measurement value. The mobile station device transmits the radio frame of the downlink dedicated physical channel to the station device, and the mobile station device receives the radio frame of the downlink dedicated physical channel from the DHO destination BTS to establish chip synchronization.

Next, an example of a conventional mobile station device that performs the above-described operation at the time of DHO will be described. FIG. 6 shows an example of a conventional mobile station apparatus in which the number of branches of space diversity used to reduce the effect of fading is two.
2 shows an example of the configuration of the mobile station device, and an example of the configuration and operation of the mobile station device will be described below. In the following, the two branches are shown as branch 1 and branch 2, respectively.

The antenna 11a of the branch 1 and the branch 2
Antenna 11b receives a radio signal. The radio section 12a of the branch 1 converts the frequency of the high-frequency signal received by the antenna 11a of the branch 1 and converts the signal into a baseband signal. The radio section 12b of the branch 2 converts the frequency of the high-frequency signal received by the antenna 11b of the branch 2 and converts the signal into a baseband signal. The A / D converter 13a of the branch 1 converts a baseband analog signal output from the radio unit 12a of the branch 1 into a digital signal, and the A / D converter 13b of the branch 2 outputs a base signal output from the radio unit 12b of the branch 2. Converts a band analog signal to a digital signal.

When a spreading code number reported from a base station apparatus on the transmitting side is externally set, the spreading code generator 14 generates a long code and a short code corresponding to the number. Note that the spread code generator 14 generates a spread code (code) used for despreading the received signal (the above-described digitized baseband signal) by using the branch 1, branch 2, and a plurality of delay paths of each branch. A code can be generated independently for each timing.

The matched filter (searcher) 15a of the branch 1 is a code obtained by multiplying the baseband signal output from the A / D converter 13a of the branch 1 by the long code and the short code generated by the spreading code generator 14, or , The correlation with the code of the short code only. Matched filter (searcher) 1 of branch 2
5b calculates a correlation between the baseband signal output from the A / D converter 13b of the branch 2 and a code obtained by multiplying the long code and the short code generated by the spreading code generator 14, or a code consisting of only the short code. I do.

[0015] Profile section of branch 1 (Profile)
16a estimates the delay path timing by taking the absolute value of the correlation operation result of the matched filter 15a of the branch 1 and averaging over a plurality of symbols.
The profile unit 16b of the branch 2 estimates the delay path timing by taking the absolute value of the correlation operation result of the matched filter 15b of the branch 2 and averaging over a plurality of symbols.

The sliding correlator (SC) 17a of the branch 1 is an A / D converter 13a of the branch 1.
The correlation calculation between the baseband signal converted into a digital value by the above and the spread code generated by multiplying the long code and the short code generated by the spread code generator 14 is performed by the profile unit 16.
By performing at the path timing estimated in a, the baseband signal is despread, and the despread signal is output.
The sliding correlator 17b of the branch 2 performs a correlation operation between the baseband signal converted into a digital value by the A / D converter 13b of the branch 2 and a spread code generated by multiplying the long code and the short code generated by the spread code generator 14. By performing at the path timing estimated by the profile unit 16b, the baseband signal is despread, and the despread signal is output.

The RAKE combining section 18 combines the results of the correlation operation (despread signals) of the delay paths having different phases obtained by the sliding correlators 17a and 17b of the branch 1 and the branch 2 at the maximum ratio and demodulates the received signal.
Here, at the time of DHO, it is necessary to receive a perch channel radio frame of the DHO destination BTS and establish synchronization with the DHO destination BTS. Therefore, the mobile station device needs a synchronization circuit that receives the DHO destination perch channel, despreads it, and determines the downlink long code and establishes the synchronization of the radio frame.

For example, in the conventional mobile station apparatus shown in FIG. 6, a matched filter (searcher) 19 dedicated to a DHO destination perch channel, a profile section 20 and a sliding correlator 21 are matched filters 15a used in two-branch space diversity. , 15b, profile sections 16a, 16b, and sliding correlators 17a, 17b.

The mobile station apparatus shown in FIG.
An example of the operation performed at the time is shown. The mobile station device is a DHO
Sometimes, the time difference between the radio frame of the uplink dedicated physical channel transmitted to the DHO source BTS and the radio frame of the perch channel transmitted from the DHO destination BTS is measured, and the measured time difference (frame time difference measured value) is calculated. D
Notify the DHO destination BTS via the HO source BTS. In order to measure this time difference, it is necessary to synchronize with a perch channel radio frame transmitted from the DHO destination BTS.

That is, first, the mobile station device converts the perch channel signal received from the DHO destination BTS into a baseband signal by the radio unit 12b or the A / D converter 13b of the branch 2, and converts the signal into a long code. The correlation is calculated by the sliding correlator 21. In the mobile station apparatus shown in FIG. 6, such a long code is generated by the spreading code generator 14, and the correlation between the perch channel signal converted into the baseband signal and the generated code is matched. The path is detected by the filter 19 and the effective path is detected by the profile unit 20 from the plurality of delay paths. As the long code used at this time, the long code number is broadcast from the DHO source BTS to the mobile station apparatus, and the phase is the same as that of the DHO destination perch channel.

Next, the mobile station apparatus operates as described above.
When the synchronization with the radio frame of the HO destination perch channel is established, as described above, the time difference between the radio frame of the DHO destination perch channel and the radio frame of the currently transmitted uplink dedicated physical channel is measured, and the measured time difference is calculated. Notify the DHO destination BTS via the DHO source BTS. D
The HO destination BTS transmits a downlink dedicated physical channel radio frame to the mobile station device at a transmission timing based on the frame time difference measurement value notified from the mobile station device, and the mobile station device transmits the downlink dedicated physical channel from the DHO destination BTS. And starts a process of establishing downlink chip synchronization.

When the mobile station apparatus establishes chip synchronization with the DHO destination BTS, it operates the matched filter 19, detects a plurality of delay path timings by the profile unit 20, and slides while maintaining the established synchronization. The received signal is despread by the correlator 21,
The RAKE combining unit 18 performs a maximum ratio combining process.

Next, another example of the conventional mobile station apparatus which performs the operation at the time of DHO as described above will be described. FIG. 7 shows, as another example of a conventional mobile station apparatus, a configuration example of a mobile station apparatus in the case where the number of branches of space diversity used to reduce the effect of fading is 2, as described above. A configuration example and an operation example of the mobile station device will be described below. In the following, the two branches are shown as branch 1 and branch 2 as described above.

The mobile station apparatus shown in FIG. 2 includes, for example, antennas 31a and 31b, radio sections 32a and 32b, and A / D converters 33a and 33b similar to those provided in the mobile station apparatus shown in FIG. , A spread code generator 34, matched filters (searchers) 35a, 35b, profile units 36a, 36b, a sliding correlator 37a,
37b and a RAKE combining unit 38, and a memory 39 for holding a perch channel signal received from the DHO destination BTS during DHO.

Here, the processing units 31a to 33a and 31b other than the memory 39 provided in the mobile station apparatus shown in FIG.
~ 33b, 34, 35a ~ 37a, 35b ~ 37b, 3
Since the configuration and operation of the memory 8 are substantially the same as those provided in the mobile station apparatus shown in FIG. 6, for example, an operation example of the memory 39 at the time of DHO will be mainly described below.

In the mobile station device, when performing DHO, DH
It is necessary to notify the O source BTS of the time difference between the radio frame of the perch channel received from the DHO destination BTS and the radio frame of the uplink dedicated physical channel transmitted to the DHO source BTS. For this reason, the mobile station device must establish synchronization with the perch channel radio frame transmitted from the DHO destination BTS. The long code used at this time is DHO
The long code number is broadcast from the source BTS, and the phase is the same as the perch channel of the DHO destination BTS.

At the time of DHO, the memory 39 has a branch 2
The signal converted into the baseband signal by the wireless unit 32b and the A / D converter 33b is held. This signal is held in the memory 39 in units of one symbol or several symbols. The memory 39 is used, for example, in a first-in first-out manner, that is, when the arithmetic processing of the previously held signal is performed first, and the arithmetic processing of the previously held signal is terminated, the signal is discarded and held. The written signal is shifted, and the next signal is written in the empty space.

Matched filters (searchers) 35a, 3
5b operates on the pilot symbol portion in the radio frame received from the DHO source BTS, and transmits the signal held in the memory 39 to the matched filter 35b of the branch 2 in the portion other than the inactive pilot symbol. Thereby, the matched filter 35 of the branch 2
b detects a path by performing a correlation operation between the long code generated by the spreading code generator 34 and the signal transmitted from the memory 39 based on the long code number broadcast from the DHO source BTS. The profile unit 36b detects a valid path from a plurality of delay paths. In this way, the mobile station apparatus shown in FIG. 7 establishes synchronization with the DHO destination perch channel radio frame.

After the synchronization is established as described above, the mobile station device transmits the radio frame of the perch channel and the DHO source BTS to the DHO source BTS when received from the DHO destination BTS. The time difference from the radio frame of the uplink dedicated physical channel is notified. This time difference is notified from the DHO source BTS to the DHO destination BTS, and DH
The O-destination BTS sets the timing of the radio frame of the downlink dedicated physical channel to the DHO
The downlink dedicated physical channel is adjusted so as to match the timing of the radio frame of the downlink dedicated physical channel transmitted from the TS (accurately to match the reception timing of the radio frame in the mobile station device). Transmit the wireless frame.

As a result, the mobile station apparatus can receive the DHO source BT
The radio frame of the downlink dedicated physical channel from the DHO destination BTS is received at the same timing as the radio frame of the downlink dedicated physical channel from S, and the process of chip synchronization is started. Then, after establishing the chip synchronization, the mobile station device despreads the received signal by the sliding correlators 37a and 37b, and performs the maximum ratio combining process by the RAKE combining unit 38.

As described above, in the mobile station apparatus shown in FIG. 6 and the mobile station apparatus shown in FIG. 7, a synchronization circuit (for example, a searcher, a profile section, and a sliding correlator) for a DHO source BTS is provided as a hardware configuration. Separately from DH
By providing a dedicated synchronization circuit and memory for the destination BTS, the DH is maintained while the process of receiving the signal transmitted from the DHO source BTS by the two-branch diversity is continued.
Establishing synchronization with the O-destination BTS is realized.

[0032]

However, in the mobile station apparatus as described above, the DHO destination BTS
Since a dedicated synchronization circuit and memory are provided, there is a problem in that the scale of hardware is greatly increased by such a synchronization circuit and memory that operates only at the time of DHO, and the cost and power consumption are further increased.

The present invention has been made to solve such a conventional problem, and synchronizes with a base station apparatus based on a pilot symbol signal wirelessly transmitted from the base station apparatus at predetermined time intervals. It is an object of the present invention to provide a mobile station device that can realize, with a simple configuration, synchronization with a plurality of base station devices at the time of handover when establishing and wirelessly communicating with the base station device.

[0034]

In order to achieve the above-mentioned object, a mobile station apparatus according to the present invention is adapted to communicate with a base station apparatus based on a pilot symbol signal wirelessly transmitted from the base station apparatus at predetermined time intervals. When establishing synchronization and performing wireless communication with the base station apparatus, synchronization with a plurality of base station apparatuses is established at the time of handover as follows. That is, an antenna that receives a signal wirelessly transmitted from the base station device, and a synchronization establishing unit that establishes synchronization with the base station device based on a pilot symbol signal received from the base station device, wherein the control unit has at least At the time of handover between different base station apparatuses, synchronization with the plurality of base station apparatuses is established by using the synchronization establishing means in a time division manner.

Therefore, for example, since one synchronization establishing means is used in a time-sharing manner at the time of handover, synchronization with a plurality of base station apparatuses is established. Therefore, it is necessary to establish synchronization with a plurality of base station apparatuses at the time of handover. This can be realized with a simple configuration, whereby, for example, the size of hardware can be reduced and the weight can be reduced, and the cost and power consumption can be reduced.

In the mobile station apparatus according to the present invention, for example, diversity handover (DHO) is performed, and synchronization with a plurality of base station apparatuses is established at the time of handover as follows. That is, a plurality of antennas are provided and a synchronization establishing means is provided for each antenna, and a synthesizing means for synthesizing signals of the same information obtained by the plurality of antennas and the synchronization establishing means is provided. At the time of handover, the synchronization with the plurality of base station apparatuses is established by using one of the plurality of synchronization establishing means in a time division manner.

Accordingly, for example, in the same manner as described above, the synchronization with a plurality of base station apparatuses is established by using one synchronization establishing means in a time division manner at the time of handover. Can be realized with a simple configuration, whereby, for example, the scale of hardware can be made small and light, and the cost and power consumption can be reduced.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment according to the present invention will be described with reference to the drawings. Note that, in this example, a case is shown in which the present invention is applied to a mobile station apparatus that performs synchronization establishment processing at the time of DHO, for example, as described with reference to FIGS. FIG.
Shows a configuration example of the mobile station apparatus of the present example in which the number of branches of space diversity used for reducing the effect of fading is 2, for example, and a configuration example and an operation example of this mobile station apparatus will be described below. explain. In the following,
The two branches are shown as branch 1 and branch 2, respectively.

As shown in the figure, the mobile station apparatus of the present embodiment has antennas 1a and 1b, radio units 2a and 2b, A / D converters 3a and 3b, (Searcher) 5a,
5b, profile parts (Profile) 6a, 6b and sliding correlators (SC) 7a, 7b are provided, and a spreading code generator 4 and a RAKE combining part 8 are provided as a common configuration for the branches 1 and 2. Have been.

The antenna 1a of the branch 1 has a function of receiving a signal wirelessly transmitted from, for example, a base station apparatus and outputting the signal to the radio unit 2a of the branch 1. The antenna 1b of the branch 2 has a function of receiving a signal wirelessly transmitted from, for example, a base station apparatus and outputting the signal to the wireless unit 2b of the branch 2. In this example, the antennas 1a and 1b constitute an antenna for receiving a signal wirelessly transmitted from the base station device according to the present invention. In this example,
In order to perform space diversity, a plurality of antennas are provided.

The radio section 2a of the branch 1 has a function of converting a high-frequency reception signal input from the antenna 1a into an analog baseband signal and outputting the analog baseband signal to the A / D converter 3a of the branch 1. The radio unit 2b of the branch 2 has a function of converting a high-frequency reception signal input from the antenna 1b into an analog baseband signal and outputting the analog baseband signal to the A / D converter 3b of the branch 2.

The A / D converter 3a of the branch 1 has a function of converting an analog baseband signal input from the radio unit 2a into a digital baseband signal and outputting the digital baseband signal to the matched filter 5a and the sliding correlator 7a of the branch 1. . A / D converter 3b of branch 2
It has a function of converting an analog baseband signal input from the radio unit 2b into a digital baseband signal and outputting the digital baseband signal to the matched filter 5b and the sliding correlator 7b of the branch 2.

The spreading code generator 4 responds to the setting of a spreading code number notified by wireless communication from the base station apparatus by a control unit (not shown) or the like. , And the generated code is transferred to branch 1 and branch 2
Has a function of outputting to the matched filters 5a and 5b and the sliding correlators 7a and 7b. Note that the spread code generator 4 of this example, when generating a spread code (code) used for despreading the received signal (the above-described digitized baseband signal), uses the branch 1, the branch 2, and each A code can be generated independently for each timing of a plurality of delay paths of a branch.

The matched filter 5a of the branch 1 is A /
It has a function of calculating the correlation between the baseband signal input from the D converter 3a and the spreading code generated by the spreading code generator 4, and outputting the calculation result to the profile unit 6a of the branch 1. The matched filter 5b of the branch 2 calculates the correlation between the baseband signal input from the A / D converter 3b and the spreading code generated by the spreading code generator 4, and outputs the calculation result to the profile unit 6b of the branch 2. Has a function.

The profile section 6a of the branch 1 takes the absolute value of the operation result input from the matched filter 5a,
It has a function of estimating the timing of the delay path by averaging the absolute value over a plurality of symbols, and has a function of notifying the sliding correlator 7a of the branch 1 of the estimated path timing. The profile part 6b of the branch 2 is a matched filter 5b
Has a function of estimating the timing of the delay path by taking the absolute value of the operation result input from, and averaging the absolute value over a plurality of symbols. 7b.

In this example, the matched filter 5 described above is used.
According to the present invention, a and 5b and the profile units 6a and 6b are controlled by, for example, a control unit (not shown) to establish synchronization with the base station device based on a pilot symbol signal received from the base station device. Synchronization establishing means for establishing synchronization with the base station device based on a pilot symbol signal received from the base station device is configured. In this example, a synchronization establishing means is provided for each of the antennas 1a and 1b (that is, each branch).

In this example, a radio frame of a perch channel similar to that shown in FIG. 3 is broadcast (radio-transmitted) from the base station apparatus to the mobile station apparatus. The pilot symbol signal shown corresponds to a pilot symbol signal wirelessly transmitted from the base station apparatus according to the present invention at predetermined time intervals. After establishing synchronization with the base station apparatus based on such a pilot symbol signal, the mobile station apparatus of this example wirelessly communicates data signals and the like with the base station apparatus using a radio frame of a dedicated physical channel. In this example, the signal of each channel is transmitted from the base station apparatus to the mobile station apparatus using a multiplexing method such as time division multiplexing, frequency division multiplexing, and code division multiplexing.

Sliding correlator 7 of branch 1
“a” despreads the baseband signal by performing a correlation operation between the baseband signal input from the A / D converter 3 a and the spreading code generated by the spreading code generator 4 at the timing of the path estimated by the profile unit 4. Then, it has a function of outputting the despread signal to the RAKE combining unit 8. The sliding correlator 7b of the branch 2 is A /
By performing a correlation operation between the baseband signal input from the D converter 3b and the spreading code generated by the spreading code generator 4 at the timing of the path estimated by the profile unit 4, the baseband signal is despread and despread. And a function of outputting the resulting signal to the RAKE combining unit 8.

The RAKE combiner 8 combines the correlation calculation results (despread signals) of the delay paths having different phases input from the sliding correlators 7a and 7b of the branch 1 and the branch 2 at the maximum ratio and demodulates the received signal. It has the function to do. In the present example, such a RAKE combining unit 8 combines signals of the same information (despread signals) obtained in the respective branches, so that the same information obtained by a plurality of antennas and synchronization establishing means according to the present invention is obtained. Combining means for combining the signals is configured. Note that, in this example, the reception efficiency is also increased by RAKE-combining a signal (a signal of the same information that has been despread) for each delay path having a different phase.

With the above configuration, in the mobile station apparatus of the present embodiment, for example, in a 2-branch diversity, the searcher composed of the matched filters 5a and 5b calculates the correlation between the received signal of each branch and the spreading code. The path detection and synchronization acquisition of the delay profile are performed, and the profile sections 6a and 6b estimate the path timing of the delay profile by accumulating and averaging the results of the correlation operation in the matched filters 5a and 5b in symbol units. . And the sliding correlators 7a, 7b
The data demodulation (despreading) unit configured from the above obtains a correlation between the received signal and the spread code for each chip at the path timing estimated by the profile units 7a and 7b, and accumulates the result to obtain 1 Symbol (for one spreading code)
Is output to the RAKE combining unit 8, and the RAKE combining unit 8 inputs the correlation values for two branches for each path, and combines the correlation values at the maximum ratio to combine the correlation values.

Further, in the mobile station apparatus of this embodiment, for example, the control unit (not shown) operates the matched filter 5b and the profile unit 6b of the branch 2 described above at the time of DHO in a time-sharing manner. 5 realizes a synchronization establishment process at the time of DHO similar to that described with reference to FIG.
The details will be described below.

That is, the matched filter 5b and the profile unit 6b of the branch 2 performing the synchronization acquisition are:
Each slot (in this example, 10 symbols as shown in FIG. 3B, for example) operates at the pilot symbol portion of the first four symbols, and does not operate at other symbol portions. Therefore, the radio frame of the perch channel wirelessly transmitted from the DHO source base station device (DHO source BTS) and the radio frame of the perch channel wirelessly transmitted from the DHO destination base station device (DHO destination BTS) have one value. By operating the matched filter 5b and the profile unit 6b in a time-division manner such that the matched filter 5b and the profile unit 6b are operated every slot (time corresponding to one slot), the DHO element B
The synchronization with the DHO destination BTS is established while continuing the process of receiving the downlink dedicated physical channel radio frame transmitted from the TS by the two-branch diversity.

FIG. 2 conceptually shows an example of the synchronization establishing process performed by the matched filter (searcher) 5b of the branch 2 of the present embodiment. Specifically, FIG. 2A shows an example of a radio frame of a perch channel when the mobile station apparatus receives the DHO source BTS,
FIG. 3B shows an example of a radio frame of the perch channel when the mobile station device receives the DHO destination BTS, and FIG. 3C shows the matched filter 5b of the mobile station device.
7 shows an example of a process of establishing synchronization based on pilot symbols from a base station device which differ every time for one slot.

The above-mentioned DHO source BTS is a base station device with which the mobile station device originally communicated wirelessly at the time of handover, and the mobile station device newly communicates with the above-mentioned DHO destination BTS at the time of handover. It is a base station device that starts communication. For example, when the mobile station apparatus moves from the communicable area of the base station apparatus 1 to the communicable area of another base station apparatus 2, the DHO source BTS
Means the base station apparatus 1, and the DHO destination BTS means the base station apparatus 2.

In this example, for example, as described above,
By operating the matched filter 5b and the profile unit 6b of the branch 2 in a time sharing manner at the time of HO, the DHO source BTS
And control for establishing synchronization with a plurality of base station devices by using a synchronization establishing means in a time-sharing manner at least at the time of handover between different base station devices according to the present invention by establishing synchronization with the DHO destination BTS. Means are configured. In this example, the control means is one of a plurality of synchronization establishing means (in this example, branch 2
Is used in a time-division manner to establish synchronization with a plurality of base station apparatuses. Further, the process of using the synchronization establishing means in a time-sharing manner can be performed at a time other than the handover, for example. However, in the present invention, it is sufficient that the process is performed at least at the time of the handover.

Further, an example of the operation performed by the mobile station device of this example at the time of DHO will be described. First, at the start of DHO, the mobile station apparatus of this example sends a DHO
Upon receiving from the destination BTS, a time difference between the radio frame of the perch channel and the radio frame of the uplink dedicated physical channel transmitted to the DHO source BTS is notified. In order to perform this notification, the mobile station apparatus of the present example uses the DHO destination BTS
Establishes synchronization with the perch channel radio frame transmitted from.

Specifically, in the mobile station device of this example, DH
The matched filter 5b, which is a searcher of the branch 2, is operated at intervals of one slot with respect to the perch channel from the O destination BTS, and the received signal is input to the matched filter 5b via the A / D converter 3b.
At the same time, a long code corresponding to the long code number broadcast from the DHO source BTS is generated by the spreading code generator 4, and the generated long code is matched with the matched filter 5b.
To enter.

The matched filter 5b performs a correlation operation between the input received signal and the long code, detects a path and maintains synchronization, and the profile unit 6b detects a valid path from a plurality of delay paths. Do. In this manner, the mobile station apparatus of the present example uses the perch channel radio frame transmitted from the DHO destination BTS to transmit the DHO destination BT.
Establish synchronization with S.

In this example, the long code used for the signal received from the DHO destination BTS is the DHO source BTS.
Is notified to the mobile station device using, for example, a long code number.
There is no need to determine the long code of the perch channel radio frame received from S, and its phase is DHO destination B
This is the same as the phase of the perch channel transmitted from the TS.

Further, the mobile station apparatus of the present embodiment has a DHO source BT
Similarly to the above, the matched filter 5b, which is the searcher of the branch 2, is operated at intervals of one slot from the perch channel from S, and the matched filter 5a, which is the searcher of the branch 1, is always applied to the perch channel. In this case, the reception processing by the diversity of two branches is continued even at the time of DHO.

Next, the DHO source BTS compares the time difference notified from the mobile station device with the DHO destination BTS via, for example, a line.
Notify. Next, the DHO destination BTS is the DHO source BT.
The base station adjusts the timing of the radio frame of the downlink dedicated physical channel based on the time difference notified from S, and matches the timing with the timing of the radio frame of the downlink dedicated physical channel transmitted from the DHO source BTS. Note that, as a preferable aspect, exactly, the timing at which the radio frame of the downlink dedicated physical channel from the DHO source BTS is received by the mobile station device, and the timing at which the radio frame of the downlink dedicated physical channel from the DHO destination BTS is determined by the mobile station device It is better to match the timing of reception.

Then, the mobile station device is, for example, a DHO destination B
At the timing based on the reception timing of the perch channel radio frame transmitted from the TS, the DHO destination BTS
And receives a radio frame of a downlink dedicated physical channel wirelessly transmitted from the base station, and starts a chip synchronization process using the radio frame. The phase of the long code does not change, for example, with the timing of the perch channel. After the chip synchronization is thus established, the mobile station device despreads the received signal by, for example, the sliding correlators 7a and 7b, and combines the signals despread by the RAKE combining unit 8 by a maximum ratio combining process.

As described above, in the mobile station apparatus of this example, D
Synchronization with a plurality of base station apparatuses is established by using the matched filter 5b or the like in a time-division manner at the time of HO. Synchronization with the DHO destination BTS can be established while continuing the process of receiving the received signal by the two-branch diversity, thereby performing a handover without instantaneously interrupting communication.

Therefore, in the mobile station apparatus of the present embodiment, it is possible to realize the synchronization with a plurality of base station apparatuses at the time of handover with a simple configuration, thereby reducing, for example, the scale of hardware. And cost and power consumption can be reduced. Also, by realizing such hardware miniaturization and cost reduction,
It is possible to improve the usability of the mobile station device by the user.

In this example, as a configuration particularly effective for applying the mobile station apparatus according to the present invention, a plurality of base station apparatuses (for example, a DHO source BTS and a DHO destination BTS) are asynchronous with each other, and wirelessly transmit a perch channel. The case where the mobile station apparatus of the present example is applied to a system for transmitting a frame is shown. That is, in such a configuration, for example, the pilot symbol signal transmitted from the DHO source BTS and the DHO destination BTS
Since there is a possibility that the pilot symbol signal transmitted from the mobile station device may overlap at the same time, synchronization with each base station device is performed by, for example, time-division processing for each slot, as in the above-described mobile station device. Establishing is especially necessary.

On the other hand, in a configuration in which the radio frames of the perch channel transmitted from a plurality of base station apparatuses are synchronized with each other, for example, the phase of the pilot symbol signal in the radio frame of the perch channel is made different between the base station apparatuses. It is also possible to hold. For this reason, in the mobile station device, for example, each base station device (for example, the DHO source BTS and the DHO
By changing the long code for each phase corresponding to the HO destination BTS, it is also possible to establish synchronization for each base station device using the same matched filter (searcher) 5b or the like. Therefore, in such a configuration, the mobile station apparatus does not need to perform the time-division processing for each slot as in this example,
For example, by performing synchronization establishment processing for the DHO destination BTS at a symbol portion other than the pilot symbol signal (ie, a phase different from the phase of the pilot symbol signal) in the radio frame of the perch channel when received from the DHO source BTS, The same effect as described above can be obtained.

Here, the configuration of the mobile station apparatus according to the present invention is not necessarily limited to the configuration shown in the above embodiment.
In short, various configurations may be used as long as synchronization is established with the plurality of base station devices by using the synchronization establishing means in a time division manner at least at the time of handover between different base station devices.

For example, the number of antennas and the number of synchronization establishing means provided in the mobile station apparatus according to the present invention are not particularly limited, and diversity reception or diversity handover using a plurality of antennas is not necessarily required as in the above embodiment. May not be performed. The method of using the synchronization establishing means in a time-sharing manner is not particularly limited, and the time-sharing processing for each slot does not always have to be performed as in the above embodiment.

Further, the synchronization establishment processing at the time of handover performed by the mobile station apparatus according to the present invention may be controlled by the processor executing a control program in a hardware resource including a processor and a memory, for example. Also, for example, each functional unit for executing the processing may be configured as an independent hardware circuit. Further, the present invention can be understood as a computer-readable recording medium such as a floppy disk or a CD-ROM storing the above-described control program, and the control program is input from the recording medium to the computer and executed by the processor. Thereby, the processing according to the present invention can be performed.

Further, for example, various configurations may be used as the configuration of the base station device, or the method of establishing synchronization between the base station device and the mobile station device. As an example,
Various signals may be used as the pilot symbol signal wirelessly transmitted from the base station device at predetermined time intervals as long as synchronization with the mobile station device can be established. Also, the predetermined time is not particularly limited,
The time does not necessarily have to be constant.

Further, in the above embodiment, a preferred embodiment shows a case where the mobile station apparatus according to the present invention is applied to a communication system adopting a CDMA system such as W-CDMA which is currently under study. However, the present invention
As long as synchronization with the base station device is established based on a pilot symbol signal transmitted from the base station device, the present invention can be applied to various systems.

[0072]

As described above, according to the mobile station apparatus of the present invention, synchronization with the base station apparatus is established based on the pilot symbol signal wirelessly transmitted from the base station apparatus at predetermined time intervals. At the time of wireless communication with the base station device, at least at the time of handover between different base station devices, the synchronization with the plurality of base station devices is established by using time-division synchronization establishment means. Establishing synchronization with the base station device can be realized with a simple configuration, whereby, for example, the scale of hardware can be reduced and the cost and power consumption can be reduced.

Further, the mobile station apparatus according to the present invention has a configuration in which a plurality of antennas are provided, a synchronization establishing means is provided for each antenna, and signals of the same information obtained by the plurality of antennas and the synchronization establishing means are combined. At least at the time of handover between different base station apparatuses, since one of the plurality of synchronization establishing means is used in a time division manner to establish synchronization with the plurality of base station apparatuses, for example, at the time of DHO Establishing synchronization with a plurality of base station apparatuses can be realized with a simple configuration as described above.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a mobile station device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a synchronization establishment process performed by a mobile station device.

FIG. 3 is a diagram illustrating an example of a radio frame of a perch channel.

FIG. 4 is a diagram illustrating an example of a reception timing of a radio frame in a mobile station device.

FIG. 5 is a diagram illustrating an example of a procedure of synchronization establishment processing performed at the time of DHO.

FIG. 6 is a diagram illustrating an example of a mobile station device according to a conventional example.

FIG. 7 is a diagram showing another example of the mobile station device according to the conventional example.

[Explanation of symbols]

1a, 1b ... antenna, 2a, 2b ... radio section, 3
A, 3b A / D converter, 4 spreading code generator, 5a, 5b matched filter (searcher), 6
a, 6b profile section, 7a, 7b sliding correlator, 8 RAKE combining section,

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K059 CC03 CC04 DD33 DD35 EE03 5K067 AA26 AA33 BB04 CC10 DD13 DD19 DD25 EE02 EE24 GG11 HH22 HH24 JJ36 JJ39 KK01

Claims (2)

[Claims] A mobile station device that establishes synchronization with the base station device based on a pilot symbol signal wirelessly transmitted from the base station device at predetermined time intervals and wirelessly communicates with the base station device. An antenna for receiving a signal wirelessly transmitted from the device, synchronization establishment means for establishing synchronization with the base station device based on a pilot symbol signal received from the base station device, at least during handover between different base station devices Control means for establishing synchronization with the plurality of base station apparatuses by using synchronization establishing means in a time-sharing manner. 2. The mobile station apparatus according to claim 1, further comprising: a plurality of antennas; a synchronization establishing means for each antenna; and synthesizing signals of the same information obtained by the plurality of antennas and the synchronization establishing means. The control means establishes synchronization with the plurality of base station apparatuses by using one of the plurality of synchronization establishing means in a time-division manner at least at the time of handover between different base station apparatuses. A mobile station device characterized by the above-mentioned.