JP4303581B2 - Reception level measuring method and mobile terminal - Google Patents

Description

The present invention relates to a reception level measurement method and a mobile terminal , and more particularly to a technique suitable for measurement of a reception level in a CDMA (Code Division Multiple Access) mobile terminal.

  FIG. 13 is a block diagram showing a configuration of a main part (receiving system) of a mobile terminal (CDMA terminal) used in a conventional mobile communication system [W (Wideband) -CDMA system]. As shown in FIG. In general, a CDMA terminal includes a radio reception unit 101, an analog / digital (A / D) converter 102, a path search unit 103, a despreading unit 104, a synchronous detection unit 105, a signal processing unit 106, and a level measurement unit as a reception system. The signal arriving from a plurality of paths received by the wireless reception unit 101 is converted into a digital signal by the A / D converter 102, and the path search unit 103 is based on the digital signal. Measure the delay profile of the received signal (determine the correlation value between the received signal and the spreading code assigned to the channel) to detect multiple paths with high correlation power (delay profile) File measurement), and the despreading timing is given to the despreading unit 104 for each path so that the detected signal of each path is despread with the same phase.

  As a result, the signals of a plurality of paths with large correlation power detected by the path search unit 103 are despread by the corresponding finger units in the despreading unit 104, and then input to the synchronous detection unit 105, where the synchronous detection unit 105 At 105, synchronous detection is performed. The signals of each path after the synchronous detection are subjected to RAKE synthesis, and then received signal processing such as channel codec, error correction (turbo decoding), interleaving, and rate matching is performed by the signal processing unit 106. Details of path search, despreading, and the like are disclosed in, for example, Patent Document 1 below.

  On the other hand, the level measuring unit 107 detects a desired signal / interference wave ratio (SIR) and a received signal strength indicator (RSSI). That is, SIR is detected by measuring and calculating the dispersion of each signal point with respect to the reference phase by DSP (Digital Signal Processor) firmware or the like based on the common pilot channel signal component of the rake composite output, and the amplitude of the signal point is measured. The RSSI is detected by calculation. These SIR and RSSI are used for closed-loop transmission power control that compensates for so-called perspective problems and for monitoring the transmission power of neighboring base stations.

By the way, in the mobile communication system, the peripheral level measurement function in the mobile terminal is an important function for selecting a standby cell and a handover destination. The SIR and RSSI described above can be used as the level measurement method.
JP 2000-40981 A

However, in the above-described conventional mobile terminal, it is necessary to separately prepare a processing system (finger unit or the like) necessary for level measurement in the despreading unit 104 and the synchronous detection unit 105 (see FIG. 13). In addition, there is a problem that power consumption increases.
The present invention was devised in view of such problems, and can achieve highly accurate reception level measurement by effectively removing noise from a received signal while greatly reducing the circuit scale and power consumption of a mobile terminal. The purpose is to do so.

In order to achieve the above object, the reception level measuring method of the present invention (Claim 1) performs a correlation operation with a received signal using a spreading code, and passes the path used for despreading and rake combining. In the reception level measurement method when performing a search ,
A plurality of path timings corresponding to a plurality of paths targeted for despreading and rake combining detected by the previous path search, and a plurality of targets for despreading and rake combining detected by the current path search between a plurality of path timings corresponding to the path, and extracts all path timing in relation Pasutai timing matches, a correlation power corresponding to a path timing, which is extracted as determined by the path search of the previous, the It is characterized in that the level of a desired wave is measured by adding the correlation power corresponding to the extracted path timing obtained by the current path search .
The reception level measuring method of the present invention (Claim 2) also performs a correlation operation with a received signal using a spread code, and performs a path search of a path used for despreading and rake combining. In the measurement method , a plurality of path timings corresponding to a plurality of paths targeted for despreading and rake combining detected by the previous path search, and a target for despreading and rake combining detected by the current path search, All the path timings having a relationship in which the path timings coincide with each other within a predetermined allowable range among the plurality of path timings corresponding to the plurality of paths to be extracted, and extracted by the previous path search. The correlation power corresponding to the path timing is added to the correlation power corresponding to the path timing extracted by the current path search. It is characterized by measuring the level of the desired wave and.

Here, in the level measurement, the predetermined allowable range may be a timing deviation within 0.5 chip .

In of al, a mobile terminal of the present invention (Claim 4), by performing a correlation operation between the received signal using the spreading code, the path search unit for performing a path search path used for despreading and RAKE combining In the mobile terminal provided, a plurality of path timings corresponding to a plurality of paths to be subjected to despreading and rake combining detected by the previous path search, and despreading and rake combining detected by the current path search Means for extracting all path timings having a path timing matching relationship with a plurality of path timings corresponding to a plurality of target paths, and the extracted path obtained by the previous path search The level of the desired wave is obtained by adding the correlation power corresponding to the timing and the correlation power corresponding to the path timing extracted by the current path search. It is characterized by having a means for measuring .
Further, the mobile terminal of the present invention (Claim 5) includes a path search unit that performs a correlation calculation with a received signal using a spreading code and performs a path search of a path used for despreading and rake combining. In the mobile terminal, a plurality of path timings corresponding to a plurality of paths targeted for despreading and rake combining detected by the previous path search, and a target for despreading and rake combining detected by the current path search, Means for extracting all the path timings having a relationship in which the path timings coincide with each other within a predetermined allowable range among the plurality of path timings corresponding to the plurality of paths, and the extraction obtained by the previous path search And the correlation power corresponding to the path timing extracted and the correlation power corresponding to the path timing extracted by the current path search are added. And a means for measuring the level of the desired wave.
Here, in the mobile terminal, the predetermined allowable range may be a timing deviation within 0.5 chip.

  According to the present invention described above, only the correlation value of the path having the same detection timing in the previous path search and the current path search is selected, or only the correlation value of the path exceeding the predetermined threshold is selected. By adding (level measurement), it is possible to greatly reduce the probability that the noise component will be selected as the desired received signal, so that the noise component is effective while significantly reducing the circuit scale and power consumption of the mobile terminal. Therefore, it is possible to realize level measurement with high accuracy.

[A] Outline Description In the mobile terminal, as described above, in the path search (delay profile measurement), the correlation value between the received signal and the spreading code assigned to itself is calculated. The more power is consumed, the more power is consumed. The waiting time of the mobile terminal is an important factor for the performance of the terminal, and this time is desired to be as short as possible. Here, the correlation value is calculated even when there is no signal and only noise. That is, in the path search, the power value is calculated at all timings within the window width as shown in FIG. 4, but it does not mean “0” because there is no signal. When selecting the top N paths (N is a natural number) in all samples within the window width of the correlation value, the noise power when noise is mixed therein becomes a value significantly larger than the average value.

  In general, the power distribution of noise is represented by an exponential function as shown in FIG. From FIG. 5, it can be confirmed that the difference between the average value of the noise and the value when the noise happens to be large is large. The longer the time for calculating the correlation value, the greater the noise power, the greater the difference from the signal power, so that it can be distinguished from smaller signals. However, as mentioned above, the calculation time should be as short as possible. . When this time is determined, the limit value of the signal power that can be identified is determined. This limit power is P1.

  On the other hand, the level determined to be out of range is not appropriate if there is too much difference between terminals, and is generally determined by the system. This determination level is P2. If the limit power P1 that can be identified is greater than the determination level P2, it is determined to be within the range even when there is no signal and only noise, so it is necessary to set it lower than the determination level P2. Also, in the W-CDMA system, rake combining is performed when data is received, so we want to measure the reception quality after rake combining as a level measurement. For this purpose, it is appropriate to measure the level of the signal after rake synthesis.

  At this time, the limit power P1 is a value that can exist as marginal noise, so the level measurement result when there is no signal is about limit power P1 × N (path). And if this exceeds the determination level P2, it will be determined that it is within the range even though there is no signal. That is, if N is the number of paths for rake combining, a problem occurs when P1 <P2 <P1 × N. Conversely, it is necessary to take a long path search time in the path search unit 5 so that P1 satisfying P1 × N <P2 can be identified. However, in the following embodiment, the limit power P1 satisfying P1 <P2 is Make sure that there is no problem with the path search time that can be identified.

That is, since P1 <P2, it is noted that the minimum power for one path of a identifiable magnitude is smaller than the out-of-service determination level, and the signal is correlated, but the noise is not correlated.
In other words, if there is a signal, it is selected as the top N path. However, the N path is not limited to a signal, and noise may be mixed therein. Therefore, a path search is performed again, and if it is selected again as the top N path, it is determined as a signal, and if it is not selected, it is determined as noise.

In addition, a method is also conceivable in which the power value of the upper N path exceeding the limit power P1 is determined as a signal, and only the excess power is synthesized to be the power after rake (level measurement result).
Further, since noise has no correlation in the time direction, there is a method in which a path search is performed once, a timing is determined, a path search is performed again, and the power value at this time is added to obtain a level measurement result. This method uses the fact that if the timing selected in the first path search is noise, it becomes an average noise level in the second path search, and therefore becomes smaller.

A specific implementation example will be described below.
[B] Description of Embodiment FIG. 1 is a block diagram showing a configuration of a main part of a mobile terminal (CDMA terminal) according to an embodiment of the present invention. The mobile terminal shown in FIG. , Wireless reception unit 3, A / D converter 4, path search unit 5, despreading unit 6, synchronous detection unit 7, signal processing unit 8, SIR / RSSI measurement unit 9, D / A converter 10, wireless transmission unit 11 and a level measurement unit (reception level measurement device) 12.

  Here, the duplexer 2 is for inputting a radio signal received by the antenna 1 to the radio receiving unit 3, and for outputting a radio signal from the radio transmitting unit 11 to the antenna 1. The radio receiving unit 3 The received signal from the duplexer 2 is subjected to required reception processing such as frequency conversion (down-conversion) from RF (Radio Frequency) to IF (Intermediate Frequency), QPSK quadrature detection, etc., and an A / D converter 4 Converts the output of the wireless receiver 3 into a digital signal.

The path search unit 5 measures a delay profile at a predetermined cycle (for example, once every 625 μs), detects a plurality of paths having large correlation power, and transfers them to the despreading unit 6 (finger unit) as despreading timing (path timing). For example, as shown in FIG. 2, a matched filter 51, a power generation circuit 52, a path selection / timing calculation circuit 53, and the like are provided.
Here, the matched filter 51 opens a window that can detect a multipath (for example, a range of 62.5 μs) around the previous path timing, and receives signals (data) at all timings in the window. The signal value (desired wave) of the own channel is extracted (detected) by obtaining the correlation value between the signal and the spreading code of the own channel, and the power circuit 52 uses the correlation filter 51 to obtain the correlation. The value is converted into a power value, and the path selection / timing calculation circuit 53 compares the magnitudes of the correlation power values and selects the top N paths (N is a natural number) in order from the largest (see FIG. 4). Then, the (detection) timing is calculated, and the despreading unit 6 applies the despreading unit to the finger unit provided for each path in the despreading unit 6 so that the detected N-path signals are despread in the same phase. It adapted to provide timing (path timing). For the delay profile measurement, a sliding correlator can be used instead of the matched filter 51.

  The despreading unit 6 despreads the output of the A / D converter 4 at the finger unit corresponding to the N path according to the despreading timing given from the path search unit 5, and the synchronous detection unit 7 The output of the despreading unit 6 is synchronously detected and rake combined, and the signal processing unit 8 performs received signal processing such as channel codec, error correction (turbo decoding), interleaving, and rate matching.

  The SIR / RSSI measuring unit 9 detects the ratio of desired wave to interference wave (SIR) and desired wave received power (RSSI), and generates control information of base station transmission power based on the detection result. The SIR can be detected by measuring and calculating the variance of each signal point with respect to the reference phase from the rake composite output by DSP firmware or the like, and the RSSI can be detected by measuring and calculating the amplitude of the signal point.

  The D / A converter 10 converts the base station transmission power control information from the SIR / RSSI measurement unit 9 into an analog signal, and the radio transmission unit 11 converts the analog signal (control information) into a radio signal. The radio signal is transmitted from the antenna 1 to the base station through the duplexer 2 for closed-loop transmission power control that compensates for a so-called perspective problem.

The level measuring unit 12 measures the level of the received signal (desired wave) of the own channel based on the correlation power values and timings for N paths obtained by the path search unit 5, as shown in FIG. In addition, a holding circuit 121, a timing comparison / path selection circuit 122, and an addition circuit 123 are provided.
The holding circuit 121 is for holding the correlation power value and timing (information) for N paths obtained by the path search unit 5, and the timing comparison / path selection circuit (selection circuit) 122 is the holding circuit. The timing of the upper N paths by the previous path search held in 121 is compared with the timing of the upper N paths by the current path search obtained by the path search unit 5 next, and the m paths having the same timing are compared. (M is a natural number, and m ≦ N) is selected (selected), and the adder circuit 123 synthesizes the correlated power values for m paths selected by the timing comparison / path selection circuit 122. (Added) and output as a level measurement result.

  In this manner, the path search unit 5 that is originally required for data demodulation is configured to perform level measurement using the correlation power value, thereby allowing the demodulation unit (despreading unit 6 and synchronous detection unit 7) to perform level measurement. There is no need to provide a circuit unit such as a correlator for level measurement, and the circuit scale and power consumption can be reduced. Further, since the correlation power value itself has already been calculated by the path search unit 5, the configuration of the level measurement unit 12 can be simplified.

  In the CDMA terminal of the present embodiment configured as described above, the path search section by the path search unit 5 is divided into two, the top N paths having a high correlation power value in the first half, and the correlation power value in the second half in the same manner. The higher N paths are selected by the path selection / timing calculation circuit 53 and only the paths having the same timing are combined by the adder circuit 123. For example, as shown in the upper part of FIG. 6, the correlation power values of the upper four paths are selected in the first half (first time) path search, and as shown in the lower part of the figure, the upper four paths are selected in the second half (second time) path search. If the correlation power value is selected, the timing of the four paths held in the holding circuit 121 as the first path search result and the timing of the four paths selected in the second path search are compared in timing. Only the correlation power values of the paths (2 paths in FIG. 6) that are compared by the path selection circuit 122 and have the same timing as indicated by reference numeral 21 are added (combined) as the correlation power value of the desired wave. Is done.

  That is, if the slot is about 1 slot [= 2560 chips (1 sample is 4 samples)], the correlation of the signals is sufficiently large. Therefore, if it is a desired wave, the same timing as the previous time (first time) in the current (second time) path search. If the path selected in the previous path search is noisy, there is no correlation with the current path search and it is selected as the top N path in this path search. As described above, by selecting and adding (level measurement) only the correlation power values of the paths that have the same timing in the previous path search and the current path search as described above, the noise component can be received. The probability of being selected as can be greatly reduced. As a result, it is possible to prevent the area from being determined as having no desired wave.

[B1] Description of First Modification In the above-described example, only the correlation power values having the same timing among the upper N paths selected in the first and second path searches are selected and added. Although the timing is highly correlated, the clocks of the base station and the mobile terminal may be slightly different from each other, and may not completely match. In addition, when the path interval is narrow and the signal power between the paths is close, the timing at which the power is strong may be slightly shifted due to a subtle change in noise.

  Therefore, for example, as shown in FIG. 7, even if both timings do not completely match, the deviation is within a predetermined allowable range [eg, 2 samples (0.5 chips) in the case of 4 samples per chip] ( In the timing comparison / path selection circuit 122, the correlation power value of the same path is regarded as being included in the correlation value to be added, and is synthesized by the addition circuit 123. As a result, appropriate level measurement can be performed even if the timings of the paths selected in the first and second path searches are slightly different.

[B2] Description of Second Modification By the way, in the level measurement described above, if there is no path having the same timing (or within an allowable range), if the level measurement result is set to 0, the level measurement is performed several times. When the results are averaged to make the in-range / out-of-range determination, the average value of the measurement results is greatly affected. Therefore, in order to prevent this, for example, as shown in FIG. 8, when there is no path having the same timing (or within a predetermined sample) in the first and second path searches, the maximum noise value (limit power) A constant value of about P1) is output from the adder circuit 123 as a level measurement result. Thereby, what should be determined to be out of service area can be prevented from being erroneously determined to be in service area.

[B3] Description of Third Modification The level measurement unit 12 described above is replaced with a threshold comparison / path selection circuit 122 instead of the timing comparison / path selection circuit 122 described above with reference to FIG. It can also be configured with ′. This threshold comparison / path selection circuit (selection circuit) 122 ′ uses the level at which the signal and noise can be substantially identified by the path search by the path search unit 5 as a threshold, and the correlation power value of the upper N paths selected by the path search unit 5 Are compared with the threshold value, and only those exceeding the threshold value are selected. Thereby, for example, as shown in FIG. 10, among the upper N (= 4) paths selected by the path search by the path search unit 5, the correlation power values for paths (3 paths) exceeding the threshold (see reference numeral 23). Are combined by the adder circuit 123 and output as a level measurement result.

In this case, unlike the above-described embodiment and the first and second modified examples, a path with a correlation power value equal to or lower than the threshold value selected as the top N path cannot be saved. Can be combined (added) even when they deviate in a short period of time, and level measurement can be performed.
Here, if there is no path exceeding the above threshold value, if the level measurement result is set to 0, the average value of the measurement result is greatly affected when the level measurement result is averaged several times and the range / out-of-range determination is performed. In order to prevent this, for example, as shown in FIG. 11, when there is no path exceeding the threshold, a constant value of about the maximum noise value (limit power P1) is used as the level measurement result as an addition circuit. 123 to output. Thereby, what should be determined to be out of service area can be prevented from being erroneously determined to be in service area.

  In addition, even though there is a signal (desired signal), it may have been lower than the threshold value. In this case, if the value of the limit power P1, which is the maximum noise level, is taken as the level measurement result, The level measurement result is larger than the power of. The limit power P1 has a higher level than a signal that may have been missed and is lower than a level that falls within the range, and is considered an appropriate value.

[B4] Description of Fourth Modification In the example described above with reference to FIG. 6, the path search section is divided into two, and the timing among the upper N paths selected in the first half (first time) and second half (second time) path search. For example, the upper N path is selected in the first half and the N path timing power values selected in the first half of the path search performed in the second half are combined. Level measurement can also be performed. In other words, only the timing information for the upper N paths selected in the first path search is held in the holding circuit 121 to determine the timing of the path to be synthesized, and obtained in the second path search at that timing. The correlation power values of the obtained paths are synthesized by the adder circuit 123 and output as a level measurement result (see reference numeral 24 in FIG. 12).

  Since the signal (desired wave) has a correlation, if the correlation power value is calculated again (by the second path search), a large value is measured again, but the noise has no correlation, so the first path search The timing at which the correlation power value was large by chance was selected, but when measuring again (by the second pass search), the average level is likely to be observed, so the signal (desired signal) Compared with electric power, it becomes negligibly small, and this is combined and there is no problem as a result of measuring the level of the desired wave. In this case, since the holding circuit 121 only needs to hold the timing information, the capacity can be reduced as compared with the measurement method described above with reference to FIG.

Further, the present invention is not limited to the above-described embodiments and modifications, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.
[C] Appendix (Appendix 1)
In a mobile terminal having a path search unit for detecting a correlation value of a higher N (N is a natural number) path having a large correlation with a spreading code assigned to itself from received signals arriving via a plurality of paths,
Of the paths obtained by the current path search by the path search unit, select the correlation value of the path that matches the detection timing of the top N paths obtained by the previous path search,
A reception level measuring method, comprising: measuring a level of a desired reception wave by adding selected correlation values.

(Appendix 2)
Supplementary note 1 characterized in that, in the level measurement, a path whose detection timing is within a predetermined allowable range in the previous and current path searches is regarded as the same path, and a correlation value of the path is included in the addition target. Reception level measurement method.
(Appendix 3)
In a mobile terminal having a path search unit for detecting a correlation value of a higher N (N is a natural number) path having a large correlation with a spreading code assigned to itself from received signals arriving via a plurality of paths,
Of the correlation values of the top N paths obtained by the path search by the path search unit, select a correlation value exceeding a predetermined threshold value,
A reception level measuring method, comprising: measuring a level of a desired reception wave by adding selected correlation values.

(Appendix 4)
4. The reception level measurement method according to any one of appendices 1 to 3, wherein in the level measurement, when there is no selected correlation value, a fixed value that is determined to be out of service is used as the level measurement result.
(Appendix 5)
In a mobile terminal having a path search unit for detecting a correlation value of a higher N (N is a natural number) path having a large correlation with a spreading code assigned to itself from received signals arriving via a plurality of paths,
Store the detection timing at which the correlation value obtained by the previous path search by the path search unit falls within the upper N paths,
Select the correlation value obtained at the stored detection timing in the current path search,
A reception level measuring method, comprising: measuring a level of a desired reception wave by adding selected correlation values.

(Appendix 6)
Reception level measurement used for a mobile terminal provided with a path search unit for detecting a correlation value of a higher-order N (N is a natural number) path having a large correlation with a spreading code assigned to itself from received signals arriving via a plurality of paths A device,
A holding circuit that holds the correlation value and timing information of the top N paths obtained by the previous path search in the path search unit;
Based on the timing information held by the holding circuit, among the paths obtained by the current path search by the path search unit, the correlation value of the path that matches the detection timing of the upper N paths obtained by the previous path search A selection circuit for selecting
A reception level measuring apparatus, comprising: an addition circuit that adds the correlation values selected by the selection circuit and outputs the result as a level measurement result of a desired reception wave.

(Appendix 7)
The selection circuit is configured to regard a path whose detection timing is within a predetermined allowable range in the previous and current path searches as the same path and select a correlation value of the path as a correlation value to be added. The reception level measuring apparatus according to appendix 6, wherein:
(Appendix 8)
A reception level measuring apparatus used for a mobile terminal provided with a path search unit for detecting a top N (N is a natural number) path having a large correlation with a spreading code assigned to itself from a received signal,
A selection circuit that compares the correlation value of the top N paths obtained by the path search by the path search unit with a predetermined threshold and selects a correlation value exceeding the threshold;
A reception level measuring apparatus, comprising: an addition circuit that adds the correlation values selected by the selection circuit and outputs the result as a level measurement result of a desired reception wave.

(Appendix 9)
Any one of Supplementary notes 6 to 8, wherein the adder circuit is configured to output a constant value as an out-of-range determination as a level measurement result when there is no correlation value selected by the selection circuit. The reception level measuring apparatus according to item 1.
(Appendix 10)
Reception level measurement used for a mobile terminal provided with a path search unit for detecting a correlation value of a higher-order N (N is a natural number) path having a large correlation with a spreading code assigned to itself from received signals arriving via a plurality of paths A device,
A holding circuit for storing a detection timing at which the correlation value obtained by the previous path search by the path search unit falls within the upper N paths;
A selection circuit for selecting a correlation value obtained at the detection timing stored in the holding circuit in the current path search;
A reception level measuring apparatus, comprising: an addition circuit that adds the correlation values selected by the selection circuit and outputs the result as a level measurement result of a desired reception wave.

  As described above in detail, according to the present invention, it is possible to realize highly accurate level measurement that effectively removes noise components while greatly reducing the circuit scale and power consumption of a mobile terminal. It is considered extremely useful.

It is a block diagram which shows the structure of the principal part of the mobile terminal (CDMA terminal) which concerns on one Embodiment of this invention. It is a block diagram which shows the structural example of the path search part shown in FIG. It is a block diagram which shows the structural example of the level measurement part (reception level measurement apparatus) shown in FIG. It is a figure which shows typically an example of the relationship between the correlation electric power value obtained by the path search part shown in FIG. 1, and timing. It is a figure which shows the power distribution example of a general noise. It is a figure for demonstrating the reception level measuring method in the mobile terminal of this embodiment. It is a figure for demonstrating the 1st modification of the reception level measuring method in the mobile terminal of this embodiment. It is a figure for demonstrating the 2nd modification of the reception level measuring method in the mobile terminal of this embodiment. It is a block diagram which shows the structure of the level measurement part which concerns on the 3rd modification of this embodiment. It is a figure for demonstrating the 3rd modification of the reception level measuring method in the mobile terminal of this embodiment. It is a figure for demonstrating the 3rd modification of the reception level measuring method in the mobile terminal of this embodiment. It is a figure for demonstrating the 4th modification of the reception level measuring method in the mobile terminal of this embodiment. It is a block diagram which shows the structure of the principal part (reception system) of the mobile terminal (CDMA terminal) used for the conventional mobile communication system [W (Wideband) -CDMA system].

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna 2 Duplexer 3 Radio | wireless receiving part 4 A / D converter 5 Path search part 51 Matched filter 52 Power generation circuit 53 Path selection and timing calculation circuit 6 Despreading part 7 Synchronous detection part 8 Signal processing part 9 SIR / RSSI measurement Unit 10 D / A converter 11 Wireless transmission unit 12 Level measurement unit (reception level measurement device)
121 holding circuit 122 timing comparison / path selection circuit (selection circuit)
122 'threshold comparison / path selection circuit (selection circuit)
123 Adder circuit

Claims (6)

In the reception level measurement method in the case of performing a path search of a path used for despreading and rake synthesis by performing a correlation operation with a received signal using a spreading code ,
A plurality of path timings corresponding to a plurality of paths targeted for despreading and rake combining detected by the previous path search, and a plurality of targets for despreading and rake combining detected by the current path search between a plurality of path timings corresponding to the path, and extracts all path timing in relation Pasutai timing matches,
The correlation power corresponding to the path timing extracted by the previous path search and the correlation power corresponding to the path timing extracted by the current path search are added to obtain the desired wave level. A reception level measuring method, comprising: measuring. In the reception level measurement method in the case of performing a path search of a path used for despreading and rake synthesis by performing a correlation operation with a received signal using a spreading code ,
Plurality being a plurality of path timings corresponding to a plurality of paths that are subject to previous times despread detected by Pas Susachi of and rake combining, the subject of this despreading is detected by the path search and RAKE combining Extract all the path timings in which the path timings match with each other within a predetermined allowable range with a plurality of path timings corresponding to the path of
The correlation power corresponding to the path timing extracted by the previous path search and the correlation power corresponding to the path timing extracted by the current path search are added to obtain the desired wave level. and measuring, reception level measurement method. 3. The reception level measuring method according to claim 2 , wherein the predetermined allowable range is a timing shift within 0.5 chip . In a mobile terminal equipped with a path search unit that performs a path search of a path used for despreading and rake synthesis by performing a correlation operation with a received signal using a spreading code,
A plurality of path timings corresponding to a plurality of paths targeted for despreading and rake combining detected by the previous path search, and a plurality of targets for despreading and rake combining detected by the current path search Means for extracting all path timings having a matching path timing among a plurality of path timings corresponding to the path;
The correlation power corresponding to the path timing extracted by the previous path search and the correlation power corresponding to the path timing extracted by the current path search are added to obtain the desired wave level. A mobile terminal comprising means for measuring . Performs a correlation operation between the received signal using a spreading code, Oite the mobile terminal provided with a path search section for performing a path search path used for despreading and RAKE combining,
A plurality of path timings corresponding to a plurality of paths targeted for despreading and rake combining detected by the previous path search, and a plurality of targets for despreading and rake combining detected by the current path search Means for extracting all path timings having a relationship in which path timings coincide with each other within a predetermined allowable range among a plurality of path timings corresponding to the paths;
The correlation power corresponding to the path timing extracted by the previous path search and the correlation power corresponding to the path timing extracted by the current path search are added to obtain the desired wave level. A mobile terminal comprising means for measuring .   The mobile terminal according to claim 5, wherein the predetermined allowable range is a timing shift within 0.5 chip.

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