JP2001244859A - Mobile radio communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile radio communication terminal which can efficiently assign a path to a finger circuit and then effectively improve reception quality. SOLUTION: This mobile radio communication terminal which receives a signal sent after band spreading, separates the received signal by reception paths and selectively assigns them to plural fingers to perform reverse spreading, and performs the RAKE synthesis of the outputs of the respective fingers controls reception paths which are assigned to the respective fingers or not assigned according to any of the following factors: the reception levels and reception quality of the received signal by the paths, the reception level and reception quality after the RAKE synthesis, and the reception quality by base stations.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an improvement of a mobile radio communication terminal using a spread spectrum communication technique of a direct spread system, such as a (Code Division Multiple Access) system.

[0002]

2. Description of the Related Art As is well known, a mobile radio communication system using a direct spread type spread spectrum communication technique as described in the head of this document has been widely used as a communication system having excellent noise and interference characteristics. There is a tendency to go. In this mobile radio communication system, communication is performed by spreading an information signal to be transmitted with a spread code having a band much wider than the signal.

[0003] Specifically, on the transmitting side, an information signal is represented by P
A PN code to be used, which performs spread modulation for multiplying by an N (Pseudorandom Noise) code, transmits the signal, and performs demodulation by performing despreading processing for multiplying the received signal by the same PN code on the receiving side. Are made different between different communications, thereby realizing multiple access in the same frequency band.

In general, in a mobile radio communication system, radio waves transmitted from a base station, a sector, or the like are separated into a plurality of transmission paths (hereinafter, referred to as paths) by, for example, reflection, diffraction, transmission, or the like by a building or the like. At present, a so-called multi-path phenomenon that arrives at the receiving side with a different delay time difference for each path has occurred, and at present, communication quality is degraded due to interference between paths.

[0005] On the other hand, in the mobile radio communication system of the CDMA system described above, when a band-spread radio wave is received, it is possible to separate radio waves for each path having different arrival times.

For this reason, on the receiving side, a finger circuit is assigned to each path one by one to perform despreading processing, and the processed signals are combined by the RAKE combining circuit at the same timing to combine them. The problem of interference between paths can be solved to improve communication quality.

In the CDMA mobile radio communication system, when switching base stations (handover), RAKE combining is applied to paths from a plurality of base stations or to multipaths. Communication without instantaneous interruption can be realized.

By the way, in this mobile radio communication system, the intensity of radio waves and the reception timing of each received path usually change with the position of the mobile terminal. For this reason, the mobile terminal periodically starts a process called a path search process, and monitors the intensity of the radio wave and the change of the reception timing for each received path as needed.

[0009] In the mobile terminal, based on the latest information of each path obtained by the path search processing, an optimum path is always assigned to the finger circuit, so that communication can be maintained even if the radio wave environment changes. I can do it.

[0010] In this case, whether to assign a new path detected in the path search process to the finger circuit, that is, whether or not to add the new path to the RAKE combining, is determined by setting the reception level of the new path to a predetermined threshold value. It is determined by satisfaction or with further protection steps.

That is, only the reception path having a certain level or more, or additionally, only the reception path whose existence has been confirmed for a certain time or more is assigned to the finger circuit, that is, RAKE. It will be controlled to be added to the composition.

This is because even if a path having a low reception level or a path which is observed only for a short time is added to RAKE combining, the effect on the improvement of the reception characteristics is small, so that the finger circuit is not consumed more than necessary. is there.

[0013] Similarly, it is determined whether or not a path whose reception level has decreased due to movement of a mobile terminal is excluded from RAKE combining, depending on whether the reception level of the path has fallen below a predetermined threshold. , Or with additional protection steps.

Further, it is determined whether or not to receive a multipath (including a path) from the base station or sector currently communicating or from another base station or sector, that is, whether to add or delete a branch. Is determined based on the same determination as the above-described assignment of the new path to the finger circuit.

In general, the compression ratio at the time of encoding differs depending on the type of media (for example, voice, image, data, etc.) to be communicated, and a bit error occurs due to a difference in the compression ratio and a difference in characteristics of human perception of each medium. Resistance is higher.

For example, the higher the compression rate at the time of encoding, the lower the resistance to bit errors. Therefore, it can be said that an image with a high compression rate at the time of encoding has lower resistance to bit errors than audio. In other words, the required receiving characteristics are different depending on the media type, for example, the image needs higher receiving characteristics than the audio.

In general, as the number of finger circuits to which RAKE combining is applied increases, the reception characteristics are expected to improve. However, the finger circuit, which is a finite resource,
Since it is also used for other communication and path search processing, etc., between the degree of improvement of the reception characteristics and the number of finger circuits consumed,
There is a trade-off relationship.

For this reason, from the viewpoint of efficiently allocating finger circuits, when communication with lower reception characteristics is required, communication with higher reception characteristics is required as compared with the case where higher reception characteristics are required. It is important to control not to assign more than necessary.

[0019]

However, in this type of conventional mobile radio communication system, the required reception characteristics for each communication are not taken into account for the assignment of paths to the finger circuits, so that the efficiency is high. At present, no assignment has been made.

That is, for example, finger circuits are allocated to communication requiring low reception characteristics as well as communication requiring high reception characteristics, so that finger circuits are allocated more than necessary and power consumption is increased. This leads to a problem that the increase in the number and the like are caused.

Conventionally, the relationship between the actually obtained reception characteristics and the required reception characteristics for each communication is not taken into account for the assignment of finger circuits.
The disadvantage is that a new finger circuit is allocated in the same way as a communication requiring a high reception characteristic, even if a reception characteristic more than necessary is actually obtained for a sufficient communication with a low reception characteristic. Has also occurred.

Further, in the conventional mobile radio communication system, the condition for selecting a path to be assigned to or deallocated from the finger circuit is uniformly defined regardless of information on each path. However, there is a problem that the path is not allocated despite the existence of a path having a high transmission rate, or the path with good reception quality is removed from the allocation due to instantaneous reception level deterioration such as fading.

The conventional assignment of a path to a finger circuit is performed by a path search function that obtains the power of a received signal and the phase in a path slot and selects a path having a large received power as a candidate for assignment to the finger circuit. A method of sequentially selecting as a candidate for assignment to a finger circuit by using a method such as a descending order of power and allocating to an empty finger circuit and a finger circuit to which a path of reception power lower than the reception power of the candidate path is allocated is adopted. ing.

However, in the means for allocating a path to a finger circuit by such a method, a path having a very small phase difference in a path slot (this is considered to be very likely to be the same path) differs. Since the finger circuit is assigned, the utilization efficiency of the finger circuit is reduced, and another effective path cannot be assigned to the finger circuit.

Further, a DLL (Delay Lo) is added to the finger circuit.
In the allocating means incorporating the "cked Loop", even if the different finger circuits are initially allocated as different paths, the phase difference in the path slot of the receiving path becomes extremely small due to the function of the DLL. As a result, a problem arises that the utilization efficiency of the finger circuit is reduced.

In the conventional path search means, the operation of measuring the received power for all the paths and selecting the path to be assigned to the finger circuit based on the measurement result is periodically repeated. I have. For this reason, a considerable time difference is required from when the received power is measured to when the received signal of the selected path is actually supplied to the finger circuit, and the possibility that the path exists is considerably reduced. Problems have arisen.

Therefore, the present invention has been made in consideration of the above circumstances, and it is possible to efficiently assign paths to finger circuits, and it is possible to effectively improve reception quality. An object of the present invention is to provide an extremely good mobile radio communication terminal.

[0028]

SUMMARY OF THE INVENTION A mobile radio communication terminal according to the present invention receives a signal subjected to a spread spectrum process and transmits the received signal. Are subjected to despreading processing by selectively assigning them to the respective fingers, and RAKE combining the outputs of the fingers.

The reception paths to be assigned to or deassigned from the plurality of fingers are at least received level, reception quality, R
A finger assignment control means for controlling based on any one of the reception level after AKE combining, the reception quality, and the reception quality for each base station is provided.

A mobile radio communication terminal according to the present invention receives a signal which has been subjected to band spreading processing and is transmitted. The mobile radio communication terminal separates the received signal into a plurality of reception paths and separates the received signals into a plurality of fingers. It is intended to selectively deallocate and perform despreading.

Measuring means for measuring the output level of the finger to which the receiving path is assigned, or the reception quality of the receiving path assigned to the finger, and comparing the measurement result of the measuring means with a predetermined threshold value Based on the result,
A comparison means for controlling assignment or release of a reception path to a finger, and a correction means for correcting a threshold value used in the comparison means based on desired communication quality.

Further, the mobile radio communication terminal according to the present invention receives a signal which has been subjected to band spreading processing and is transmitted. The mobile radio communication terminal separates the received signal into a plurality of reception paths and separates the received signals into a plurality of fingers. It is intended to selectively assign and despread, and RAKE combine the output of each finger.

The number of fingers to which a reception path is assigned based on at least one of the reception level of each received signal, reception quality for each path, reception level after RAKE combining, reception quality, and reception quality for each base station. Is provided.

Further, the mobile radio communication terminal according to the present invention receives a signal which has been subjected to band spreading processing and is transmitted. The mobile radio communication terminal separates the received signal into a plurality of reception paths and separates the received signals into a plurality of fingers. It is intended to selectively deallocate and perform despreading. Then, a determination means for determining that the same reception path is assigned to a different finger is provided.

Further, the mobile radio communication terminal according to the present invention receives a signal which has been subjected to band spreading processing and is transmitted. The mobile radio communication terminal separates the received signal into a plurality of reception paths and separates the received signals into a plurality of fingers. It is intended to selectively assign and despread, and RAKE combine the output of each finger. Then, the output power of each of the plurality of fingers is measured, and the output of the finger whose measured power substantially exceeds a predetermined threshold is added to the RAKE synthesis.

According to the above configuration, the paths can be efficiently assigned to the finger circuits, and the reception quality can be effectively improved.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, a spread signal received by an antenna 11 is RF (Radiation).
o) after the frequency conversion by the
The signal is sampled by a D (Analog / Digital) converter 13 to be a received baseband signal, which is supplied to a matched filter 14 and a plurality of finger circuits 15, respectively.

Among them, the matched filter 14 has a spreading code for performing synchronization acquisition as a tap coefficient, performs despreading processing on the input received baseband signal, and outputs it to the signal power integrator 16 at sample timing. I have. The signal power integrator 16 integrates the correlation output power value from the matched filter 14 for a certain period and outputs the integration result.

The output of the signal power integrator 16 is taken into the path search section 17 together with the phase in the path slot.
The phase in the pass slot of the correlation peak is detected. Then, based on the detected phase in the path slot, the path search unit 17 requests the finger management unit 18 for a set of paths to be supplied to the finger circuit 15 together with the demodulation spreading code.

The finger management section 18 sets the spreading code for demodulation and the phase in the path slot in the finger circuit 15. Then, the finger circuit 15 outputs the demodulated signal information to the path search unit 17 and
Outputs the reception level, reception quality, and phase in the path slot of the path to the new path information storage unit 19.

The finger circuit 15 demodulates the received baseband signal from the A / D converter 13 and outputs the demodulated result to the path search unit 17 and the RAKE combining unit 20, respectively. Therefore, the path search unit 17 outputs the reception level, the reception quality, and the phase in the path slot of the currently receiving path to the reception path information storage unit 21.

Further, the RAKE combiner 20 RAKE combines the demodulation result from the finger circuit 15 and outputs the received level after RAKE combining, the received quality and the received quality for each base station to the received path information storage 21 respectively. At the same time, the RAKE combining result is stored in the memory 22.

The path information stored in the new path information storage unit 19 and the received path information storage unit 21 is supplied to a finger assignment condition setting unit 23. The finger assignment condition setting unit 23 sets the priority of finger assignment and deassignment for each input path.

The priority set by the finger assignment condition setting unit 23 is supplied to the finger management unit 18. Then, the finger management unit 18 sets a path in the finger circuit 15 based on the input priority, and sets a reception level for each path,
The assignment of the finger circuit 15 is changed according to the reception quality, the phase in the path slot, and the like.

According to the first embodiment, the finger assignment condition setting unit 23 can set the priority of finger assignment or finger assignment for each path. Can be efficiently assigned, and the reception quality can be improved.

Further, based on the reception quality after RAKE combining, the priority of assignment or de-allocation of all finger circuits 15 is changed at once, or assigned to each base station based on the reception quality of each base station. Finger circuit 15
The finger circuit 15, which is a limited resource, can be used more efficiently by changing the number.

FIG. 2 is a flowchart summarizing the operation of the finger assignment condition setting unit 23. The finger assignment condition setting unit 23 has a timer (not shown), and when started (step S1), the operation is periodically executed by the timer in step S2.

That is, in step S3, the reception path is read from the reception path information storage unit 21, and the process proceeds to step S4.
Then, it is checked whether or not there is a path that satisfies the conditions for removing from the finger assignment. Then, when it is determined that there is a path that satisfies the conditions for removing from finger assignment (YE
S) In step S5, the finger management unit 18 is instructed to delete the finger assignment.

Thereafter, or if it is determined in step S4 that there is no path that satisfies the conditions for removing the finger assignment (NO), the finger circuit 1 is determined in step S6.
It is checked whether or not there is a free space in No. 5 and if it is determined that there is no free space (NO), the process returns to step S2, and if it is determined that there is a free space (YES), in step S7,
Read the reception path information from the new path information storage unit 19,
In step S8, it is checked whether or not there is a path for which conditions to be newly assigned to the finger circuit 15 are satisfied.

If it is determined that there is no path satisfying the condition to be newly assigned to the finger circuit 15 (NO), the process returns to step S2, and the path satisfying the condition newly assigned to the finger circuit 15 is determined. If it is determined that the new path exists (YES), the finger management unit 18 is instructed to add a finger assignment of a new path in step S9, and the process returns to step S2.

Since the finger assignment condition setting unit 23 performs the above-described operation, assignment to the finger circuit 15 is always performed based on the latest path information, and the switching of paths is smooth. Will be able to do it.

Next, FIG. 3A shows a first example of the priority determination of finger assignment and finger assignment removal. That is, now, assume that the path slot phase delay time 0 in the presence of a peak level, path exists it the delay time to the reference tau ₁ and tau ₂ and.

In general, it is said that a path having a longer delay time has a lower reception level and has a shorter duration. For this reason, in the case of | τ ₁ | <| τ ₂ |, it is better to assign the path of τ ₁ with priority over the path of delay time τ ₂ . In addition, it is better to preferentially remove the path of τ ₂ from the assignment than the path of delay time τ ₁ .

Therefore, the finger assignment condition setting unit 23
Then, when the delay time is shorter than τ, n ₁Times peak level
If the value exceeds p, it is assumed that the assignment condition has been satisfied.
When the distance is τ or more, n₂Times peak level -p
It is assumed that the assignment conditions are satisfied.

When the delay time is less than the delay time τ, it is assumed that conditions for removing the assignment are satisfied when the peak level falls below the peak level −p _three times, and when the delay time is more than the delay time τ, the peak level falls below the peak level −p _four times. The conditions for removal from the assignment are established. _{However, n 1 <n 2 n 3} > n is _4. Of course, the boundary delay time τ does not need to be one, and a plurality of delay times may be present, and a plurality of n may be present. Further, the magnitude relationship between n ₁ and n ₂ and between n ₃ and n ₄ may be different from the above.

Next, FIG. 3B shows a second example of the priority determination of finger assignment and finger assignment non-assignment. That is, it is assumed that the phase in the path slot where the peak level exists is set to the delay time 0, and based on the delay time, a path exists at the delay times τ ₃ and τ ₄ .

In general, it is said that a path having a longer delay time has a lower reception level and a shorter duration of the path. However, depending on the propagation environment, reflected waves from distant large buildings or mountains may cause reflected waves. There may be a path that has a large delay time and a high reception level. In such a case, it is better to assign the path of τ ₄ with priority over the path of delay time τ ₃ . Also, τ is longer than the path having the delay time τ _4.
It is better to preferentially remove path ₃ from allocation.

Therefore, the finger assignment condition setting unit 23
Then, when the delay time is shorter than τ, n ₅Times peak level
p₅If the value exceeds
If the time is longer than τ, n₆Times peak level -p₆Above
It is assumed that the allocation condition is satisfied once.

[0059] In addition, when less than the delay time τ, it is assumed that conditions be removed from the assignment Once below the n ₇ times the peak level -p ₇ is well-equipped, when more than delay time τ, n ₈ times the peak level -p ₈ It is assumed that the condition for removing from the assignment when the value falls below is satisfied. However, it is _{n 5> n 6 p 5>} p 6 n 7 <n 8 p 7> p 8. Of course, the delay time τ serving as the boundary does not need to be one, and a plurality of delay times may be present, and a plurality of n and p may be present. In addition, _{n 5} and _n 6,
p ₅ and _{p 6,} and, the magnitude relation of _{n 7} and _n 8, _{p 7} and _{p 8} are may be different from above.

Next, FIG. 3C shows a third example of the priority determination of finger assignment and finger unassignment. That is, now, assume that the path slot phase delay time 0 in the presence of a peak level, path exists it the delay time tau ₅ to standards and tau _6.

In this system, the reception quality is measured for each path, and the reception quality is set to QOS ₅ and QOS ₆ , respectively. Finger path 15 for better reception quality path
Is more likely to improve the total reception quality, so if QOS ₅ <QOS ₆ , it is better to assign the path of τ ₆ preferentially.
It is better to preferentially remove the path of τ ₅ from the assignment.

Therefore, the finger assignment condition setting unit 23
So when the above reception quality QOS, it is assumed that allocation condition is in place Once above the _{n 9} times the peak level -p, when the following reception quality _{QOS, n 10} times the peak level -p
It is assumed that the assignment condition is satisfied when the value exceeds.

When the reception quality is equal to or higher than QOS, n
_It is assumed that the condition for removing from the assignment when the peak level falls below the peak level −p ₁₁ times is satisfied.
It is assumed that the conditions for removing from the assignment when the peak level falls below the peak level −p for n ₁₂ times are satisfied. _{However, n 9 <n 10 n 11} > is _{n 12.} Of course, the reception quality QOS serving as the boundary does not need to be one, and a plurality of reception quality QOSs may be present, and a plurality of n may be present. Also, the reception quality QO
The condition may be set by combining the level difference between S and the peak level p.

FIG. 4A shows a fourth example of the priority determination of finger assignment and finger assignment elimination. That is, now, the RAKE combining unit 20 periodically outputs the reception quality after RAKE combining for the path search, and the reception quality at time T ₇ is QOS ₇ , and the reception quality at time T ₈ is QOS ₈ . Suppose there was.

When the reception quality after RAKE combining is high, it is better to maintain the reception state of the current path as much as possible, and when the reception quality is low, it is better to improve the reception state of the current path as quickly as possible.

It is assumed that the reception quality after RAKE combining as a certain reference is QOS _RAKE, and that QOS ₇ <QOS _RAKE <QOS ₈ .

Then, the reception quality after RAKE combining is QO
When S _7, FIGS. 3 (a) each condition value described in ~ (c) (n, p , QOS) the likely overall assigned finger circuits 15, shift towards easily removed from the finger assignment, RAKE synthesis When the subsequent reception quality is QOS ₈ , each of the condition values (n, p, QO) described with reference to FIGS.
S) is shifted to a direction in which it is difficult to assign the finger circuit 15 as a whole, and to remove it from the finger assignment.

Next, FIG. 4B shows an example of a method for changing the number of finger assignments for each base station. That is, at the time of a so-called handover in which one mobile terminal transmits and receives the same information to and from a plurality of base stations, the RAKE combining unit 20 periodically performs R search for each base station for path search.
And outputs the reception quality after AKE synthesis, the reception quality of the base station A at time _{T 9} are assumed _{QOS 9A,} the reception quality of the base station B was _{QOS 9B.}

For a base station with high reception quality, it is better to receive as many paths as possible using as many finger circuits 15 as possible. For a base station with low reception quality, use of finger circuit 15 is preferable. It is better to limit.

When the reception quality after RAKE combining for each base station as a reference is QOS _BTS, and the reception quality after RAKE combining for each base station is QOS _9A and QOS _9B , respectively, the number of finger circuits 15 to be assigned is N _9A and N _9B .

Then, when QOS _9A <QOS _BTS <QOS _9B (condition Z), N _9A <N _9B , and when QOS _9A > QOS _BTS > QOS _9B (condition X), N _9A > N _9B and QOS _When both _9A and QOS _9B are higher than QOS _BTS , or when both QOS _9A and QOS _9B are lower than QOS _BTS (condition Y), N _9A = N _9B .

Here, N _9A + N _9B = the total number of finger circuits. Of course, the reception quality QOS _{BTS at the} boundary
Is not required to be one, and a plurality of N may be present, and a plurality of N may be present. Also, N
The magnitude relationship between _9A and N _9B may be different from the above. Furthermore, here, the case where handover is performed with two base stations has been described, but handover with three or more base stations can be similarly described.

As described above, according to the first embodiment, the priority of assigning or unassigning a path to the finger circuit 15 can be dynamically switched for each path, so that more efficiency can be achieved. Good finger management can be performed, and reception quality can be improved.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 5, a received signal received by an antenna 24 is converted into a digital signal by an A / D converter 25, and then finger circuits 27a to 27 assigned by a finger assignment control circuit 26.
d, and then, although not shown, R
AKE is combined and demodulated.

Here, the finger assignment control circuit 2
6 denotes finger circuits 27a to 27 applied to the despreading process.
d, and the selected finger circuits 27a to 27d
By setting the PN code and the timing, the despreading process is controlled. The finger assignment control circuit 26 according to the second embodiment performs both finger assignment control for path search processing and finger assignment control for communication.

In FIG. 5, a desired quality acquisition circuit 2
Numeral 8 acquires information relating to desired quality such as a media type such as voice and data and a communication speed from control information at the time of call setting. Further, the quality measuring circuit 29 measures the output levels of the finger circuits 27a to 27d in the path search processing.

Then, the judgment circuit 30 is connected to the quality measurement circuit 2
9, the output levels of the finger circuits 27a to 27d and the threshold value for finger assignment are compared, and it is determined whether or not to assign the finger circuits 27a to 27d based on the comparison result. Further, the criterion adjustment circuit 31 determines the judgment circuit 3 based on the information on the desired quality acquired by the desired quality acquisition circuit 28.
The threshold used at 0 is adjusted.

The operation of the above configuration will be described below. That is, the finger assignment control circuit 26 assigns vacant finger circuits 27a to 27d for a path search that is periodically started. However, the path search process itself, such as a method of setting the PN code and timing at the time of the path search, is outside the scope of the present invention, and thus the description is omitted.

Then, from the finger assignment control circuit 26, any of the finger circuits 27a-2
The information indicating whether 7d is assigned is transmitted to the quality measurement circuit 2
9. Then, the quality measuring circuit 29 outputs the finger circuits 27a to 27 assigned for the path search.
d is measured, and the measurement result is determined by the judgment circuit 30.
Output to

On the other hand, the desired quality obtaining circuit 28 obtains information on desired quality such as the type of media used for communication and the communication speed from the control information at the time of call setting. In the second embodiment, it is assumed that a media type is obtained.
Then, the media type information obtained by the desired quality obtaining circuit 28 is supplied to the criterion adjusting circuit 31.

The criterion adjusting circuit 31 determines a correction amount for the level threshold for finger assignment based on a table as shown in FIG. That is, the table shown in FIG. 6 indicates that if the media type is audio, the correction amount is -Δv (dB), and if the media type is image, the correction amount is + Δi (dB).

The correction amount determined by the criterion adjusting circuit 31 is supplied to the deciding circuit 30. The determination circuit 30 has a threshold value for finger assignment, and corrects the threshold value based on the correction amount supplied from the determination reference adjustment circuit 31. In the second embodiment, the threshold for finger assignment is R
a (dBμ). Therefore, for example, if the media type is audio, the threshold value is Ra−Δv (d
Bμ).

FIG. 7 is a flowchart summarizing the judgment processing operation in the judgment circuit 30. That is,
When started (step S10), in step S11,
The determination circuit 30 determines the threshold value by a determination reference adjustment circuit 31
The value corrected by the correction amount given from the
9. When the measured value is determined to be equal to or more than the corrected threshold value (≧), the measured value is compared with the measured value measured in step 9 (step S1).
At 2, it is determined that the finger circuits 27a to 27d are to be assigned, and the process is terminated (step S13). Step S
If it is determined in step 11 that the measured value is smaller than the corrected threshold value (<), the finger circuit 27a is determined in step S14.
To 27d are not assigned, and the process ends (step S1).
3) is done.

Then, the judgment result of the judgment circuit 30 is
It is supplied to the finger assignment control circuit 26. The finger assignment control circuit 26 determines whether or not the finger circuits 27a to 27a for the paths detected in the path search process based on the finger assignment determination result given from the determination circuit 30.
7d is controlled.

As described above, in the second embodiment, the criterion for finger assignment can be adjusted according to the media types having different request levels for the reception characteristics. As a result, the finger circuit 27 is unnecessarily used for a medium having a low required level for the reception characteristic.
The conventional problem of assigning a to 27d can be solved.

In the above-described second embodiment, an example has been shown in which the media type is applied as the desired quality of communication. However, the desired quality of communication is not limited to this. Information such as an error rate can also be applied. Further, in the second embodiment, an example is described in which a threshold regarding the reception level is applied as a criterion for finger assignment. However, the criterion is not limited to this. Information such as power ratio) can also be applied.

Although an example in which only a threshold value is applied as a criterion has been described, when a protection step using the criterion a plurality of times is added, the number of protection steps is adjusted according to desired quality. Is also possible. Further, in the second embodiment, the finger circuits 27a to 27
Although the determination processing in the assignment of d has been described, the present invention can be similarly applied to the determination in releasing the finger circuits 27a to 27d that have already been allocated.

Next, FIG. 8 shows a first modification of the above-described second embodiment. That is, in FIG. 8, the same parts as those in FIG. 5 are denoted by the same reference numerals, and when assigning finger circuits 27a to 27d for communication, a branch is added [path from a sector not currently communicating (multipath RAKE combining). ) To communications).

For this reason, in the configuration of the first modification, the quality measuring circuit 29 sets the multipath for each sector to R
It is assumed that the output level obtained by RAKE combining by the AKE combining circuit 32 is measured. The determination circuit 30 compares the RAKE combined output level measured by the quality measurement circuit 29 with a threshold value for adding a branch, and determines whether or not to add a branch based on the comparison result. ing.

The operation of the above configuration will be described below. That is, in the first modified example, the path of the broadcast channel from the base station (sector) is multipath RAKE separately from the path search processing started periodically.
It is assumed that the processing of combining and measuring the level is started.

Such a process is called a perch detection process. For this perch detection process, the finger assignment control circuit 26 determines whether or not there are free finger circuits 27a-27.
Assign d. However, the perch detection processing itself, such as the method of setting the PN code and the timing at the time of perch detection, is outside the scope of the present invention, and thus the description is omitted.

The finger circuit 27 for the perch detection process from the finger assignment control circuit 26
Information indicating whether a to 27d have been assigned is supplied to the quality measurement circuit 29. Then, the quality measurement circuit 29
The output levels of the finger circuits 27 a to 27 d assigned for the perch detection process after RAKE synthesis are measured, and the measurement results are output to the determination circuit 30.

On the other hand, the desired quality obtaining circuit 28 obtains information on desired quality such as the type of media used for communication and the communication speed from the control information at the time of call setting. In the first modification, it is assumed that the media type is acquired. Then, the media type information obtained by the desired quality obtaining circuit 28 is supplied to the criterion adjusting circuit 31.

The criterion adjusting circuit 31 determines the correction amount for the level threshold value for branch addition based on the table as shown in FIG. That is,
The table shown in FIG. 9 indicates that the correction amount is -Δvb (dB) if the media type is audio, and + Δib (dB) if the media type is image.

The correction amount determined by the criterion adjustment circuit 31 is supplied to the determination circuit 30. The determination circuit 30 has a threshold value for branch addition, and corrects the threshold value based on the correction amount supplied from the determination reference adjustment circuit 31. Actually, the threshold value also takes into account transmission power information and the like broadcasted by the broadcast information. However, in the first modified example, the threshold value is simply Rab (dBμ) for simplicity. . Therefore, for example, if the media type is audio, the threshold value is R
ab−Δvb (dBμ).

Then, the judgment circuit 30 is connected to the quality measurement circuit 2
9 is compared with the corrected threshold value. If the received level value is equal to or greater than the corrected threshold value, it is determined that a branch is to be added; otherwise, no branch is added. And judge.

The result of this determination is transmitted to the network (base station) side as call control information. When the addition of a branch is approved by the network, information for instructing finger assignment is transmitted to the finger assignment control circuit 26. Then, the finger assignment control circuit 26
The finger circuits 27a to 27d are assigned so that the paths included in the branch are added to the RAKE combining based on the branch addition instruction supplied from.

As described above, in the first modified example, the criterion for adding a branch can be adjusted in accordance with media types having different request levels for reception characteristics. With this, a branch is added more than necessary for a medium having a low required level for reception characteristics.
That is, the conventional problem of allocating the finger circuits 27a to 27d can be solved.

In the first modified example,
Although an example in which a threshold regarding a reception level is applied as a criterion for adding a branch has been described, the criterion is not limited to this, and information such as SIR (desired wave to interference wave power ratio) may be applied. It is possible. Further, in the first modified example, the determination processing for adding a branch has been described, but the present invention can be similarly applied to the determination for deleting a branch.

Next, FIG. 10 shows a second modification of the above-described second embodiment. That is, in the second modified example, in FIG. 10, the same parts as those in FIG. 8 are denoted by the same reference numerals, and the configuration of the first modified example is provided with a second quality measuring circuit 33. It is.

The second quality measuring circuit 33 obtains information on the communication quality obtained in the current communication, for example, the reception levels and the SIR values of all the receiving branches used for the communication after RAKE combining. ing. In the second modification, the second quality measurement circuit 33 acquires the reception levels of all the reception branches used for communication after RAKE combining.

In the second modification, similarly to the first modification, the finger circuit 27a for communication is provided.
In addition, in the assignment of .about.27d, addition of a branch [path from a sector not currently communicating (multipath RAKE)
(Including compositing) to communications). For this reason, the criterion adjustment circuit 31 is used in the determination circuit 30 based on the output level information obtained by the second quality measurement circuit 33 after RAKE combining of all branches used for communication. Adjusting the threshold.

The operation of the above configuration will be described below. In the second modified example, the perch detection process is started as in the first modified example.
That is, the second quality measurement circuit 33 measures the reception levels of all branches currently used for communication after RAKE combining. Then, the measured reception level information is supplied to the criterion adjustment circuit 31.

The criterion adjusting circuit 31 determines a level threshold value for branch addition based on a table as shown in FIG. That is, in the table shown in FIG.
The threshold is determined based on the obtained reception level.

For example, if the media type is audio and the reception level obtained from the second quality measurement circuit 33 is R + R
If not less than v (dBμ), it is determined that a branch cannot be added and R
+ Rv (dBμ), the threshold is set to R−Δvb
(DB).

The threshold value determined by the criterion adjusting circuit 31 is supplied to the deciding circuit 30. This judgment circuit 30 is provided with the input threshold value and the quality measurement circuit 2
9 is compared with the reception level obtained. If the reception level value is equal to or larger than the threshold value, it is determined that a branch is to be added. Otherwise, it is determined that no branch is to be added.

The result of this determination is transmitted to the network (base station) side as call control information. When the addition of a branch is approved by the network, information for instructing finger assignment is transmitted to the finger assignment control circuit 26. Then, the finger assignment control circuit 26
The finger circuits 27a to 27d are assigned so that the paths included in the branch are added to the RAKE combining based on the branch addition instruction supplied from.

As described above, in the second modified example, the criteria for adding a branch are set in accordance with media types having different request levels with respect to reception characteristics, and further taking into account the actually obtained quality. Can be adjusted. Thus, when sufficient quality is currently obtained for a medium having a low required level for reception characteristics, a branch is added more than necessary, that is, finger circuits 27a to 27d are allocated. The problem can be solved.

As described above, according to the second embodiment and the two modifications thereof, the finger circuits 27a to 27a to 27f correspond to the communications having different request levels for the reception characteristics.
By determining the addition or release of the 27d, efficient finger circuits 27a to 27d that match the required reception characteristics are determined.
27d allocation control can be performed.

Further, by deciding whether to add or delete a branch according to the communication having a different required level for the reception characteristic, it is possible to efficiently control the allocation of finger circuits 27a to 27d according to the required reception characteristic. it can.

Further, according to the communication having a different required level for the reception characteristic, the addition or deletion of the branch is determined in consideration of the reception quality currently obtained, so that the required reception characteristic is adjusted. It is possible to perform efficient assignment control of the finger circuits 27a to 27d.

Next, a third embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 12, a spread signal received by an antenna 34 is frequency-converted by an RF unit 35 and then sampled by an A / D converter 36 to become a received baseband signal. A matched filter 37 and a plurality of finger circuits 38 Respectively.

Among them, the matched filter 37 has a spreading code for performing synchronization acquisition as a tap coefficient, performs despreading processing on the input received baseband signal, and outputs it to the signal power integrator 39 at sample timing. I have. The signal power integrator 39 integrates the correlation output power value from the matched filter 37 for a certain period, and outputs the integration result.

The output of the signal power integrator 39 is taken into the path search section 40 together with the phase in the path slot.
The phase in the pass slot of the correlation peak is detected. Then, based on the detected phase in the path slot, the path search unit 40 requests the finger management unit 41 to set a path to be supplied to the finger circuit 38 together with the demodulation spreading code.

The finger management unit 41 sets the spreading code for demodulation, the phase in the path slot, and the operating finger information in the finger circuit selection unit 42. Then, the finger circuit 38 outputs demodulated signal information to the path search unit 40, and the path search unit 40 outputs the reception level, reception quality, and phase in the path slot of the path to the path information storage unit 43, respectively. I do.

The finger circuit 38 demodulates the received baseband signal from the A / D converter 36, and outputs the demodulation result to the path search unit 40 and the RAKE combining unit 44, respectively. Therefore, the path search unit 40 outputs the reception level, the reception quality, and the phase in the path slot of the currently receiving path to the path information storage unit 43, respectively.

Further, the RAKE combiner 44 RAKE combines the demodulation result from the finger circuit 38 and outputs the received level, the received quality after the RAKE combined, and the received quality for each base station to the path information storage 43, respectively. With
The result of the RAKE synthesis is stored in the memory 45.

The path information stored in the path information storage section 43 is supplied to a finger number determination condition setting section 46.
The finger number determination condition setting unit 46 obtains the path information from the path information storage unit 43 and outputs the information to the finger management unit 41 when the condition superior to the finger number allocation is satisfied.

Then, the finger management unit 41
Based on the information input from the finger number determination condition setting unit 46, finger number information is set in the finger circuit selection unit 42, and the finger number is set according to the reception level, reception quality, phase in the path slot, and the like for each path. The number of assignments of the circuit 38 is changed.

In FIG. 12, the control unit 47 controls the above-described processes such as finger number change determination, finger management, and finger circuit selection in an integrated manner.

With such a configuration, the number of finger circuits 38 operated by the finger number determination condition setting section 46 can be dynamically reallocated. When the reception condition is good,
The power consumption can be reduced. Further, when the reception condition is bad, it is possible to keep the reception quality constant by using all the finger circuits 38.

FIG. 13 is a flowchart summarizing the operation of the finger number determination condition setting section 46. The finger number determination condition setting unit 46 has a timer (not shown). When the timer is started (step S15), the operation is periodically performed every time it is determined in step S16 that the timer times out (YES). Will be executed.

That is, in a state where a certain reception quality is obtained using all the finger circuits 38, step S1 is executed.
In step 7, the reception path information is read from the path information storage unit 43. In step S18, it is determined whether an additional condition for the number of fingers has occurred, and it is determined that the additional condition for the number of fingers has been satisfied. If (YES), step S19
Thus, the finger management unit 41 is instructed to add the number of fingers.

After step S19 or step S19
If it is determined in step 18 that the finger number addition condition is not satisfied (NO), it is determined in step S20 whether a condition for reducing the finger number has occurred, and it is determined that the condition is satisfied. If (YES), step S2
In step 1, the finger management unit 41 is instructed to reduce the number of fingers, and the process ends (step S22).

When it is determined in step S20 that the condition for reducing the number of fingers is not satisfied (NO), the process is terminated (step S22).

By such processing, the number of operating fingers can be maintained at an optimum number according to a change in the reception state.

FIG. 14 shows a first example of finger number determination. That is, FIGS. 14A to 14D show the case where there are four finger circuits 38 and the dispersion of the fluctuation value of the reception level of each of the four finger circuits 38. For this reception level fluctuation value, a fluctuation threshold value for finger number increase / decrease determination is set. The variation threshold for the finger number increase / decrease determination includes both when a finger is added and when a finger is reduced (determination variation threshold−, determination variation threshold +).

It is optional whether or not to set a variation threshold for finger number increase / decrease determination for each finger circuit 38. The reception level fluctuation value of each finger circuit 38 within a predetermined time is at the judgment fluctuation threshold value, for example, a threshold value having a variance value of the fluctuation value of the main finger, for example, all the reception fingers, for example, any reception finger. When the value is within the value, it is estimated that the wireless mobile terminal is used in a stationary state or a state close to the stationary state, and it can be determined that the wireless mobile terminal is in a state that can withstand the reduction in the number of fingers.

FIG. 15 shows a second example of determining the number of fingers. That is, RAKE combining section 44 outputs the reception quality after RAKE combining for the periodic path search processing. Reception quality between the time _{T 1} is assumed to have been Eb / Io _1. If the reception quality after RAKE combining is higher than a certain threshold value (Eb / Ioδ), it can be determined that the communication state is stable, and a condition for reducing the number of fingers is established. Further, the time T ₁ other sections, because the reception quality is poor, additional conditions finger number is established by adding the number of fingers, and to improve the reception quality.

As described above, according to the third embodiment, the number of operating fingers can be dynamically switched, so that the reception quality can be stabilized with lower power consumption.

Next, a fourth embodiment of the present invention will be described in detail with reference to the drawings. 16, the matched filter 48 despreads the received baseband signal sampled after the A / D conversion, and outputs the phase in the path slot of the received path to the path search unit 49.

The plurality of fingers 50 demodulate the baseband signal after the A / D conversion, output the demodulation result to the RAKE combining section 51, and output the received power and the like to the path search section 49. The RAKE combining section 51 outputs the information on the receiving path to the path information storage section 52 and stores the RAKE combining result in the memory.

The path search unit 49 selects a candidate path to be assigned to the finger 50 based on the received power of the received path and the phase in the path slot, and outputs the path to the path information storage unit 52. The path information stored in the path information storage unit 52 is supplied to the finger assignment determination unit 53.

The finger assignment determining unit 53 obtains information on the path being received from the path information storage unit 52 and information on a path that is a candidate for assignment to the finger 50, and determines the assignment of the candidate path to the finger 50. Whether or not the path can be assigned is determined, and the information of the path determined to be assignable is assigned to the finger assignment setting unit
Report to 4. Then, the finger assignment setting unit 54
Assigns the reported reception path to the finger 50.

According to the fourth embodiment, the finger 50 of the path is periodically checked by the finger assignment determining unit 53 during reception.
The assignment to the finger 50 is determined. If the path is determined to be the same as the path being received, the assignment to the finger 50 is not permitted. Therefore, the same path is assigned to a different finger 50 during reception. Is prevented, and the finger 50 can be used effectively.

FIG. 17 is a flowchart summarizing such a finger assignment determining operation. That is,
When started (step S23), in step S24,
The path search unit 49 outputs information of a path that is an allocation candidate from among the paths being received to the path information storage unit 52 and stores it.

Then, in step S25, the finger assignment determining unit 53 extracts the information of the path being received from the path information storage unit 52, and in step S26, the path information storage unit 5
After extracting the information of the path which is the candidate to be assigned to the finger 50 from No. 2, the receiving path and the candidate path are compared in step S27.

If it is determined that the receiving path and the candidate path are the same path, the process returns to step S26, and if it is determined that the receiving path and the candidate path are different paths, In S28, finger assignment determining section 53 reports the candidate path to finger assignment setting section 54 as a new reception path.

Thereafter, in step S29, it is determined whether or not the path assignment has been completed for all the fingers 50. If it is determined that the allocation has not been completed (NO), the process returns to step S26. If it is determined in step S29 that the assignment of the paths to all the fingers 50 has been completed (YES), the newly assigned paths are stored in the path information storage unit 52 as receiving paths in step S30.
The process ends (step S31).

FIG. 18 shows a modification of the above-described fourth embodiment. That is, in FIG.
When the same parts as those in FIG.
L55 is incorporated in the finger 50, and changes the phase in the path slot of the receiving path assigned to the finger 50 according to the clock frequency error between transmission and reception. The change of the phase in the path slot of the receiving path is transmitted from the finger 50 via the RAKE combining section 51 to the path information storage section 52.
Will be reported to

In FIG. 18, the receiving path finger assignment determining unit 56 obtains information on the receiving path from the path information storage unit 52, and determines whether the receiving path is effectively allocated to the finger 50. Is determined, and the result of the determination is reported to the finger assignment setting unit 54. The finger assignment setting unit 54 excludes, from the assignment to the finger 50, the reception path for which the assignment to the finger 50 is determined to be invalid.

According to this modification, the receiving path finger assignment determining unit 56 periodically determines the validity of the assignment of the path to the finger 50 during the reception, and determines the validity of the DLL 55 in accordance with a change in the phase in the path slot. When the same path is assigned to different fingers 50 during reception, it is determined that the assignment of one path to the finger 50 is not valid.
The assignment to 0 is prevented, and the finger 50 can be used effectively.

FIG. 19 is a flowchart summarizing the finger assignment determining operation of this modification. That is, when the reception is started (step S32), the path information storage unit 52 acquires the path information being received from the finger 50 in step S33, and allocates the path finger being received at an arbitrary time interval in step S34. The path information being received is output to the determination unit 56.

Thereafter, in step S35, the receiving path finger assignment determining unit 56 compares the receiving paths with each other. If it is determined that the same path exists, in step S36, one of the paths is replaced with the finger 50. In step S37, a new path is assigned to the finger 50 from which the path assignment has been excluded.

After step S37 or when it is determined in step S35 that the same path does not exist, it is determined in step S38 whether or not reception has been completed, and when it is determined that reception has been completed ( (YES), end (step S39), and when it is determined that the reception is not ended (NO), the process returns to step S33.

FIG. 20 shows a first specific example of finger assignment determination in the fourth embodiment described above. That is, in FIG. 20, a black circle indicates a path assigned to the finger 50, and a white circle indicates a path which is a candidate for assignment to the finger 50. Also, the number of fingers 50 can take any value,
Here, it is assumed that there are first to third three fingers 50 for convenience.

During the reception, the symbol a indicates the path assigned to the first finger 50, and the phase in the path slot is Ta. The symbol b indicates the path assigned to the second finger 50, and the phase in the path slot is Tb. The symbol c indicates a path assigned to the third finger 50, and the phase in the path slot is T
c.

Here, it is assumed that the path d is selected as a new finger assignment candidate by the path search unit 49 and the phase in the path slot is Td. In addition, the finger assignment determining unit 53 sets Tth as the threshold value for the same path determination.
have er. This threshold value Tther is for determining that two paths are the same path when the phase difference in the path slot of the two paths is equal to or smaller than Tther.

The finger assignment determining unit 53 determines the phase difference | Td− between the candidate path d and the path b having the smaller phase difference among the already assigned paths a, b, and c. Tb | is calculated and compared with the threshold value Tther. As a result, if | Td−Tb |> Tther, it is determined that the two paths b and d are different, and the path d
Is replaced with the path c having the lower received power among the assigned paths a, b, and c, and the finger assignment setting unit 54 is instructed to assign the third finger 50 [equivalent to (1) in FIG.

As a result of comparison, if | Td−Tb | ≦ Tther, it is determined that the two paths b and d are the same, and the path d is excluded from the allocation candidates [see (2) in FIG. Equivalent].

Further, as a result of the comparison, | Td−Tb | ≦ Tther, and when it is determined that the two paths b and d are the same, the reception power of the allocation candidate path d is equal to the reception power of the allocated path b. If the value exceeds the above, it is also possible to instruct the finger assignment setting unit 54 to replace the path b with the path d and assign the path b to the second finger 50 (corresponding to (3) in FIG. 20).

Note that the number of comparisons between the phase difference in the path slot and the threshold can be set arbitrarily. Further, the value of the threshold value Tther is also arbitrary.

FIG. 21 shows a first specific example of finger assignment determination in a modification of the above-described fourth embodiment. Also in this case, the number of fingers 50 can take any value, but here, it is assumed that there are first to third fingers 50 for convenience.

During the reception, the symbol a indicates the path assigned to the first finger 50, and the phase in the path slot is Ta. The symbol b indicates the path assigned to the second finger 50, and the phase in the path slot is Tb. The symbol c indicates a path assigned to the third finger 50, and the phase in the path slot is T
c.

The receiving path finger assignment determining unit 56
Has Tther as a threshold for determining the same path. This threshold value Tther is for determining that two paths are the same path when the phase difference in the path slot of the two paths is equal to or smaller than Tther.

The receiving path finger assignment determining unit 5
6 is between passes assigned to each finger 50,
The phase differences | Tb−Ta |, | Tc−Tb | and | Tc−Ta | are calculated for the respective path slots, and the calculated results are compared with the threshold value Tther.
As a result, if | Tb−Ta | ≦ Tther, it is determined that the two paths a and b are the same path, and finger assignment is performed so that the path b with low received power is excluded from the assignment to the second finger 50. The setting unit 54 is instructed.

As a result of comparison, if | Tc−Tb | ≦ Tther, it is determined that the two paths b and c are the same path, and the path c with low received power is allocated to the third finger 50. The finger assignment setting unit 54 is instructed to remove from the above.

Further, as a result of the comparison, if | Tc−Ta | ≦ Tther, it is determined that the two paths a and c are the same path, and the path c with low received power is allocated to the third finger 50. The finger assignment setting unit 54 is instructed to remove from the above.

In this case as well, the number of comparisons between the phase difference in the path slot and the threshold value can be set arbitrarily. Further, the value of the threshold value Tther is also arbitrary.

FIGS. 22A and 22B show a second specific example of finger assignment determination in the above-described fourth embodiment. That is, in FIGS. 22A and 22B, black circles indicate paths assigned to the fingers 50, and white circles indicate paths that are candidates for assignment to the fingers 50. Further, the number of fingers 50 can take any value, but here, for convenience, it is assumed that there are first to third three fingers 50.

During reception, the symbol a indicates a path assigned to the first finger 50, and the reception power is Pa. The symbol b indicates a path assigned to the second finger 50, and the received power is Pb. The symbol c indicates a path assigned to the third finger 50, and the received power is Pc.

Here, it is assumed that the path d is selected as a new finger assignment candidate by the path search unit 49, and the received power is Pd. Further, the finger assignment determining unit 53 has Pther as a threshold for determining the same path. This threshold value Pther is for determining that two paths are the same path when the correlation value of the two paths is equal to or higher than Pther.

When obtaining information on a new path from the path information storage section 52, the finger assignment determining section 53 stores the received powers Pa to Pc obtained from the information on the previous path.

Here, the symbol e indicates a path assigned to the first finger 50, and the received power is Pe. The symbol f indicates a path assigned to the second finger 50, and the received power is Pf. The symbol g is the third
, Indicates the path assigned to the finger 50, and the received power is Pg. A symbol h indicates a path selected as a finger assignment candidate, and its received power is Ph.

The finger assignment determining unit 53 determines whether each finger 5
The correlation value is obtained by calculating the amount of change in the received power of the path allocated to 0 and calculating the ratio to that of the path of the finger allocation candidate path.

For example, for the first finger 50, (Pe / Pa) / (Ph / Pd) For the second finger, (Pf / Pb) / (Ph / Pd) For the third finger 50, (Pg / Pc) / (Ph / Pd) is the correlation value. The calculation of the correlation value is performed when the calculation result is 1
Should be calculated so as not to exceed.

Then, the correlation value obtained for each finger 50 is compared with the threshold value Pther. If the correlation value> Pther continues n times continuously,
It is determined that the path already allocated to 0 and the path of the allocation candidate are the same, and is excluded from the allocation candidate.

If the correlation value> Pther does not continue for n consecutive times, it is determined that the path already allocated to the finger 50 is different from the allocation candidate path, and the path having the lower received power is determined. The finger assignment setting unit 54 is instructed to assign to the finger 50 instead of the above.

The number of comparisons n can be set arbitrarily. The value of the threshold value Pther is also arbitrary.

An example in which the method of calculating the correlation value is different from that of the second specific example will be described. The finger assignment determining unit 53 has variables F1, F2, and F3 indicating the change state of the reception power for each finger 50 and a variable Fn indicating the change state of the reception power of the allocation candidate path.

Here, in each finger 50, 1 is stored in F when the received power increases (including no change), and 0 is stored in F when the received power decreases. In FIG. 22, F1 = 1 because Pe-Pa> 0, F2 = 0 because Pf-Pb <0, and F3 = 1 because Pg-Pc> 0.

The finger assignment determining unit 53 calculates exclusive OR for each combination of Fn and F1, F2, F3 as a correlation value. If the calculation result becomes 0 consecutively n times, the two paths are the same. , And if the value does not become 0 consecutively n times, it is determined that the two paths are different. Note that the number of comparisons n can be set arbitrarily.

FIGS. 23A and 23B show a second specific example of the finger assignment determination in the modification of the above-described fourth embodiment. That is, also in this case, the number of fingers 50 can take any value, but here, it is assumed that there are first to third fingers 50 for convenience.

During reception, the symbol a indicates the path assigned to the first finger 50, and the received power is Pa. The symbol b indicates a path assigned to the second finger 50, and the received power is Pb. The symbol c indicates a path assigned to the third finger 50, and the received power is Pc.

The receiving path finger assignment determining unit 56
Has Pther as a threshold for the same path determination. The threshold value Pther is such that the correlation value of the two paths is Pth
When it is equal to or more than er, the two paths are determined to be the same path.

Then, the receiving path finger assignment determining unit 5
6 indicates that when the new path information is obtained from the path information storage unit 52, the received powers Pa to Pc obtained from the previous path information are used.
Save.

Here, the symbol d indicates a path assigned to the first finger 50, and the received power is Pd. The symbol e indicates the path assigned to the second finger 50, and the received power is Pe. The symbol f is the third
, And the received power is Pf.

The receiving path finger assignment determining section 56 calculates the amount of change in the received power among the paths assigned to the fingers 50 and obtains a correlation value by calculating the ratio.

For example, for the first and second fingers 50, (Pd / Pa) / (Pe / Pb) For the second and third fingers, (Pe / Pb) / (Pf / Pc) For the first and third fingers 50, (Pd / Pa) / (Pf / Pc) is the correlation value. The calculation of the correlation value is performed when the calculation result is 1
Should be calculated so as not to exceed.

The obtained correlation value and the threshold value Pther are compared between the fingers 50, and the correlation value> Pth
If the number of consecutive er times continues n times, it is determined that the paths assigned to the two fingers 50 are the same path, and the finger having a lower received power is excluded from the assignment to the finger 50. Instruct the assignment setting unit 54.

The number of comparisons n can be set arbitrarily. The value of the threshold value Pther is also arbitrary.

Further, an example in which the calculation method of the correlation value is different in the above-described second specific example will be described. The receiving path finger assignment determining unit 56 has variables F1, F2, and F3 indicating the change state of the received power for each finger 50.

Here, in each finger 50, 1 is stored in F when the received power increases (including no change), and 0 is stored in F when the received power decreases. In FIG. 23, F1 = 1 because Pd-Pa> 0, F2 = 1 because Pe-Pb> 0, and F3 = 0 because Pf-Pc <0.

The finger assignment judging section 53 calculates exclusive OR for each of two combinations of F1, F2 and F3 as correlation values. If the calculation result becomes 0 consecutively n times, the two paths are the same. It is determined that there is. Note that the number of comparisons n can be set arbitrarily.

It is to be noted that all the specific examples described above can be used in appropriate combinations. Further, when a plurality of paths as finger assignment candidates are obtained, the determination is performed sequentially.

As described above, according to the fourth embodiment, during reception, the path allocated to the finger 50 and the path allocated to the finger 50 are periodically set so that they do not become the same path. By assigning only different paths to the fingers 50, it is possible to prevent the same path from being allocated to different fingers 50, and to improve the use efficiency of the fingers 50.

Next, a fifth embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 24, A
The / D converter 57 inputs the received signal spread and converted into I and Q by wireless demodulation means (not shown), quantizes the signal digitally at a certain sampling rate, and matches the matched filter 58 with a plurality (4 in the case shown). Fingers 59a ~
59d.

Among them, the matched filter 58 calculates the correlation between the received signal and the set synchronization symbol spreading code, generates a synchronization addition signal indicating the correlation at each sample timing, and outputs the signal to the peak search section 60. are doing.

The peak search section 60 extracts, as path timings, sample timings in which the largest m peaks are present among the peaks in the synchronous addition signal supplied from the matched filter 58, and extracts them as path candidate storage sections 61. To supply.

On the other hand, in FIG.
2 knows an empty finger from the empty finger information storage unit 63 and gives an information symbol spreading code synchronized with the path timing to one of the fingers 59a to 59d. Then, fingers 59a to 59d despread the received signal with the given spreading code, and provide demodulated symbols to power measurement determination section 64 and RAKE combining section 65.

Here, the power measurement / determination section 64 measures the power of the symbols output from the fingers 59a to 59d, determines whether or not the power is equal to or greater than a threshold value, and does not use the power for RAKE combining. When the power of the fingers 59a to 59d is equal to or higher than the threshold value, the fingers 59a to 59d during RAKE synthesis
If the power exceeds d, the fingers 59a to 59d used for power measurement and the fingers 59a to 59d used in the power measurement are output to the finger selecting unit 66 as synthesized finger information during the RAKE synthesis.

The finger selecting section 66 supplies the RAKE combining section 65 with fingers 59a to 59d for RAKE combining based on the combined finger information, and the empty finger information storage section 63 stores the fingers 59a not included in the combined finger information.
~ 59d. Then, RAKE combining section 65 converts the symbols of given fingers 59a to 59d into RAKE
Combine.

In the above configuration, an operation related to the path switching process will be described below. That is, the peak search unit 60 extracts path timings from the matched filter 58 in descending order of power, and supplies the path timings to the path candidate storage unit 61 in the extracted order.

The path information setting section 62 stores the path candidate storage section 6
1 to determine which of the fingers 59a to 59d is empty from the empty finger information storage unit 63, and give the empty finger j an information symbol spreading code synchronized with the path timing.

When finger j starts despreading the received signal, power measurement / judgment section 64 measures the power using the despread signal of each of fingers 59a-59d.
The power measurement determination unit 64 compares the path timing exceeding the threshold value with the powers of the other fingers 59a to 59d, and if there is a finger k with a power smaller than the finger j, the finger k is transmitted to the finger selection unit 66. The removed fingers 59a to 59d are transmitted.

The finger selecting unit 66 performs RAK synthesis so that the transmitted fingers 59a to 59d perform RAKE synthesis.
Notify the E combining unit 65. In addition, the finger selecting unit 66
The finger k is transmitted to the empty finger information storage unit 63 so as to be used for power measurement of the next path timing, and the processing for one path timing is ended here.

If the power measurement judging unit 64 judges that the power of the finger j is smaller than that of the other fingers 59a to 59d, the finger j is used as it is for the power measurement of the next path timing candidate. These are repeated for all path timings, and the path switching processing is completed.

Further, when power is measured, the power is measured only on the broadcast channel, but the power is measured on the channel to be received.
When the fingers 59a to 59d used for the power measurement are added to the E combination, it is not necessary to re-add the spreading code to the fingers 59a to 59d, and the time until the addition to the RAKE combination can be shortened.

According to the fifth embodiment, at the processing timing as shown in FIG. 25, the path timings extracted by the matched filter 58 are processed one by one by the empty fingers 59a to 59d which are not RAKE-combined. When power is measured with a symbol spreading code and exceeds the decision threshold and replaced with other fingers 59a to 59d, the information symbols used for power measurement can be added to the RAKE combining, and the path timing by the matched filter 58 The time from extraction to reception and demodulation of symbols can be reduced.

FIG. 26 shows path switching means in a conventional mobile terminal. That is, a received signal spread and converted into I and Q by a wireless demodulation means (not shown) is digitally quantized by an A / D converter 67, and a matched filter 68 Are obtained, power is obtained at each sample timing, and synchronously added.

The result of the synchronous addition is supplied to the peak search section 69.
Thus, the range to be searched is determined from the sector position information obtained by the sector position detecting means (not shown), and m path timings are detected as m path timings in descending order of power from the sample timings in the range and supplied to the path candidate storage unit 70 You.

Subsequently, in the mobile terminal, the power measurement path information setting section 71 sequentially sets the information symbol spreading code of the base station to be searched to the power measurement finger 72 at the timing synchronized with the detected path timing. In each state, the path timing when the received power value exceeds a certain threshold in the power measurement determination unit 73,
The path is determined to be the path of the base station desired to be received, and the effective path storage 74
Give to.

Thereafter, the RA is changed at the reception path switching cycle.
The KE combining path information setting section 75 extracts path timings from the effective path storage section 74 in the order of the power in descending order of the number of received fingers, sets information symbol spreading codes synchronized therewith in the fingers 76a to 76c, and outputs the despread output to RAK.
The E combining unit 77 combines the information symbols.

In the above-described conventional path switching means, the information symbol spreading code of the base station is synchronized with the m path timings detected by using the matched filter 68 and set in the despreader. A comparison is made between the power and the threshold to determine whether or not the path is that of the base station, and the n path timings exceeding the threshold are stored as valid paths, and the reception path having a different timing from this procedure is stored. In the switching cycle, the finger 76a is switched from n path timings.
If there is a path having higher power than the path being received in to 76c, it is replaced.

In other words, the path timing is extracted as in the processing timing shown in FIG. 27, power measurement is determined for all path timings, and then the path timing of the RAKE combining finger is replaced. There is a considerable time difference from the time of measurement to the time when the fingers 76a to 76c are actually set as the reception paths, and there is a disadvantage that the possibility that the paths exist is considerably reduced.

On the other hand, according to the fifth embodiment described above, the power is measured by the information symbol for each of the path timings detected by the matched filter 58, and if it exceeds the threshold, the RAKE combining is immediately performed. Since the time from the path search to the actual demodulation of the information symbols is shortened, the multipath can frequently follow the changes in the environment where frequent occurrences and disappearances occur, and the path can be quickly followed. A diversity effect can be easily obtained, and a significant improvement in reception quality can be expected.

The present invention is not limited to the above-described embodiments, but can be implemented with various modifications without departing from the spirit and scope of the invention.

[0208]

As described in detail above, according to the present invention,
It is possible to efficiently assign paths to finger circuits, and to provide a very good mobile radio communication terminal that can effectively improve reception quality.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a mobile radio communication terminal according to a first embodiment of the present invention;

FIG. 2 is a flowchart illustrating an operation of a finger assignment condition setting unit according to the first embodiment;

FIG. 3 is a diagram illustrating first to third priority determinations of finger assignment and finger assignment in the first embodiment;
The figure shown in order to explain the example of.

FIG. 4 is a view for explaining a fourth example of the priority determination of finger assignment and finger assignment elimination in the first embodiment and an example of a method of changing the finger assignment number for each base station;

FIG. 5 is a block diagram showing a mobile radio communication terminal according to a second embodiment of the present invention;

FIG. 6 is an exemplary view for explaining an example of a table provided in a criterion adjustment circuit according to the second embodiment;

FIG. 7 is a flowchart illustrating a determination operation of a determination circuit according to the second embodiment.

FIG. 8 is a block diagram showing a first modification of the second embodiment.

FIG. 9 is a diagram illustrating an example of a table included in a determination reference adjustment circuit according to the second modified example.

FIG. 10 is a block diagram showing a second modification of the second embodiment;

FIG. 11 is a diagram illustrating an example of a table included in a determination reference adjustment circuit according to the second modified example.

FIG. 12 is a block diagram illustrating a mobile radio communication terminal according to a third embodiment of the present invention;

FIG. 13 is a flowchart shown to explain the operation of a finger number determination condition setting unit in the third embodiment.

FIG. 14 is a view for explaining a first example of finger number determination according to the third embodiment;

FIG. 15 is an exemplary view for explaining a second example of finger number determination in the third embodiment;

FIG. 16 is a block diagram showing a mobile radio communication terminal according to a fourth embodiment of the present invention;

FIG. 17 is a flowchart shown to explain an operation of finger assignment determination in the fourth embodiment.

FIG. 18 is a block diagram showing a modification of the fourth embodiment;

FIG. 19 is a flowchart shown to explain an operation of finger assignment determination in the modification.

FIG. 20 is a view for explaining a first specific example of finger assignment determination according to the fourth embodiment;

FIG. 21 is a view for explaining a first specific example of finger assignment determination in a modification of the fourth embodiment.

FIG. 22 is an exemplary view for explaining a second specific example of finger assignment determination according to the fourth embodiment;

FIG. 23 is a view for explaining a second specific example of finger assignment determination in a modification of the fourth embodiment.

FIG. 24 is a block diagram showing a mobile radio communication terminal according to a fifth embodiment of the present invention;

FIG. 25 is a view for explaining processing timing in the fifth embodiment.

FIG. 26 is a block diagram illustrating a path switching unit in a conventional mobile terminal.

FIG. 27 is a view for explaining processing timing in the conventional means.

[Explanation of symbols]

 11 antenna, 12 RF unit, 13 A / D converter, 14 matched filter, 15 finger circuit, 16 signal power integrator, 17 path search unit, 18 finger management unit, 19 new Path information storage unit, 20: RAKE combining unit, 21: reception path information storage unit, 22: memory, 23: finger assignment condition setting unit, 24: antenna, 25: A / D converter, 26: finger assignment control circuit, 27a to 27d: finger circuit, 28: desired quality acquisition circuit, 29: quality measurement circuit, 30: judgment circuit, 31: judgment reference adjustment circuit, 32: RAKE synthesis circuit, 33: second quality measurement circuit, 34: antenna 35, RF unit, 36, A / D converter, 37, matched filter, 38, finger circuit, 39, signal power integrator, 40, path 41, a finger management unit, 42, a finger circuit selection unit, 43, a path information storage unit, 44, a RAKE synthesis unit, 45, a memory, 46, a finger number determination condition setting unit, 47, a control unit, 48, Matched filter, 49: path search unit, 50: finger, 51: RAKE combining unit, 52: path information storage unit, 53: finger assignment determining unit, 54: finger assignment setting unit, 55: DLL, 56: receiving path Finger assignment determination unit, 57 A / D converter, 58 matched filter, 59a to 59d finger, 60 peak search unit, 61 candidate path storage unit, 62 path information storage unit, 63 free finger information Storage unit: 64: Power measurement determination unit: 65: RAKE combining unit: 66: Finger selection unit: 67: A / D converter; 68: Matched fill 69, a peak search unit, 70, a path candidate storage unit, 71, a power measurement path information setting unit, 72, a power measurement finger, 73, a power measurement determination unit, 74, a favorable path storage unit, 75, a RAKE combined path information Setting unit, 76a to 76c: Finger, 77: RAKE combining unit.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Atsushi Dobashi 3-1-1 Asahigaoka, Hino-shi, Tokyo Inside the Toshiba Hino Plant Co., Ltd. (72) Inventor Noritaka 3-1-1 1-1 Asahigaoka, Hino-shi, Tokyo Inside the Toshiba Hino Plant (72) Inventor Masami Morimoto 3-1-1 Asahigaoka, Hino-shi, Tokyo Inside the Toshiba Hino Plant F-term (reference) 5K022 EE02 EE31 5K059 CC03 CC07 DD35 EE02 5K067 AA23 CC10 CC24 DD44 DD45 EE02 HH21 HH22

Claims (11)

[Claims] An apparatus for receiving a signal transmitted after being subjected to a band spreading process, separating the received signal into a plurality of reception paths, selectively assigning the signals to a plurality of fingers, and performing a despreading process. In a mobile radio communication terminal that RAKE-combines the output of each finger, the reception path assigned to each of the plurality of fingers or deallocated is at least a reception level for each path of the received signal, reception quality, A mobile radio communication terminal comprising finger assignment control means for controlling based on any of a reception level after RAKE combining, a reception quality, and a reception quality for each base station. 2. The method according to claim 1, wherein the finger assignment control unit controls a priority when assigning or removing the assignment to each of the plurality of fingers with respect to the plurality of reception paths. Mobile radio communication terminal. 3. A method for receiving a signal which has been subjected to a spread spectrum processing and transmitted, separates the received signal into a plurality of reception paths, and selectively assigns the signals to a plurality of fingers to perform a despreading processing. In the mobile radio communication terminal, measuring means for measuring the output level of the finger to which the receiving path is assigned, or the receiving quality of the receiving path assigned to the finger, and a measurement result of the measuring means and a predetermined value. Comparison means for controlling assignment or release of the reception path to the finger based on a result of comparison with a threshold value, and correction means for correcting a threshold value used by the comparison means based on desired communication quality A mobile radio communication terminal characterized by comprising: 4. The mobile radio communication terminal according to claim 3, wherein the desired quality of the communication used by said correction means includes one of a media type and a communication speed used in the communication. 5. A method for receiving a signal which has been subjected to spread spectrum processing and transmitted, separates the received signal for each of a plurality of reception paths, selectively assigns the signals to a plurality of fingers, and performs despreading processing. In the mobile radio communication terminal that RAKE-combines the output of each finger, at least one of the reception level and reception quality of each path of the received signal, the reception level after the RAKE combination, the reception quality, and the reception quality of each base station A mobile radio communication terminal comprising: a control unit that controls the number of the fingers to which the reception path is allocated based on the number of the fingers. 6. A method for receiving a signal transmitted after being subjected to a band spreading process, separating the received signal into a plurality of reception paths, selectively assigning the signals to a plurality of fingers, and performing a despreading process. A mobile wireless communication terminal, comprising: a determination unit that determines that the same reception path is assigned to a different one of the fingers. 7. The method according to claim 7, wherein the determining unit determines a path slot position between a first reception path already allocated to the finger and a second reception path newly selected as a candidate for allocation to another finger. Calculate the phase difference, compare the calculated phase difference in the path slot with a predetermined threshold,
The mobile radio communication terminal according to claim 6, wherein it is determined whether the first reception path is the same as the second reception path. 8. The determination means calculates a correlation value between a first reception path already assigned to the finger and a second reception path newly selected as a candidate for assignment to another finger. Then, comparing the calculated correlation value with a predetermined threshold value, the first reception path and the second reception path are compared.
7. The mobile radio communication terminal according to claim 6, wherein it is determined whether or not the reception path is the same. 9. The determining means calculates a phase difference in a path slot of each reception path assigned to the plurality of fingers, and calculates the calculated phase difference in the path slot and a predetermined threshold value. 7. The mobile radio communication terminal according to claim 6, wherein a determination is made as to whether or not there is the same reception path. 10. The determination means calculates a correlation value of each reception path assigned to the plurality of fingers, compares the calculated correlation value with a predetermined threshold value, and 7. The mobile radio communication terminal according to claim 6, wherein it is determined whether there is a reception path. 11. A method for receiving a signal which has been subjected to a spread spectrum process and which has been transmitted, separates the received signal for each of a plurality of reception paths, selectively assigns the signals to a plurality of fingers, and performs a despreading process. In a mobile radio communication terminal that RAKE combines the output of each finger, the output power of each of the plurality of fingers is measured, and the output of the finger whose measured power substantially exceeds a predetermined threshold is The RAK
A mobile radio communication terminal, which is added to E-composition.