JP3309840B2 - Receiver circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CDMA (Code D)
More particularly, the present invention relates to a receiving circuit provided in a mobile terminal in a mobile communication system to which a CDMA system is applied.

[0002]

2. Description of the Related Art In recent years, the number of subscribers in a mobile communication system has been steadily increasing, and an increase in subscriber capacity is required. Therefore, as one method that can increase the subscriber capacity, a CDMA method in which one frequency band is shared by signals spread by a plurality of mathematically orthogonal codes has been considered.

[0003] In a mobile communication system to which the CDMA system is applied, a plurality of finger receiving units for despreading transmitted data are provided in a receiving circuit of a mobile terminal in correspondence with a plurality of multipaths. After the data is despread in each finger receiving unit, the despread data is synthesized.

FIG. 11 is a block diagram showing an example of the configuration of a finger receiving unit which the present inventors are currently experimentally studying.

[0005] In this configuration example, as shown in FIG. 11, transmitted data is converted from a reference point to 16.384 MHz at -1 / 2π, -ππ, 0π, + ／ π, + ／.
a despreading unit 1 for performing complex despreading for each of the five points of π for each chip rate; 2, a symbol power calculator 3 for converting the symbol data cumulatively added by the symbol accumulator 2 into power values and outputting the converted power values, and the five power values output from the symbol power calculator 3 as slot rates. A slot power accumulating section for performing section accumulative addition, and a maximum value detection for detecting a point having a maximum slot cumulative power value among the five complex despread points based on the addition result in the slot power accumulating section. Part 5
The symbol accumulation addition data at the point where the power value is detected as the maximum value by the maximum value detection unit 5 out of the symbol accumulation addition data accumulated by the symbol accumulation addition unit 2 is output to a subsequent circuit (not shown). And a symbol data selection unit 6 for outputting the data.

[0006] The operation of the finger receiving unit configured as described above will be described below.

FIG. 12 is a flow chart for explaining the operation of the finger receiving section shown in FIG.
FIG. 3 is a diagram illustrating an example of received data for describing an operation of the finger receiving unit illustrated in FIG. 11.

[0008] When data transmitted from a base station apparatus (not shown) is received (step S101), first, in the despreading unit 1, the transmitted data is transmitted to a 4.096 MHz signal using a despreading code. Despreading is performed at the chip rate (step S102). Here, step S102
In, the chip rate is divided into four, and 16.38
-1 / 2π,-／ π, 0π, + ／ of 4 MHz
Despreading is performed on five points of π and + ／ π.

Next, in the symbol accumulating and adding section 2, the data subjected to complex despreading in the despreading section 1 is cumulatively added for each of the above five points for each symbol rate section (step S103).

Next, in the symbol power calculation section 3,
The symbol data cumulatively added by the symbol cumulative addition unit 2 is converted into a power value and output (step S104).

Next, in the slot power accumulating and adding section 4, the five power values output from the symbol power calculating section 3 are cumulatively added in one time slot rate section (step S105).

Next, the maximum value detecting section 5 detects the point at which the slot cumulative power value becomes maximum among the above five complex despread points based on the addition result in the slot power cumulative adding section 4 ( Step S106).

Thereafter, the result of detection by the maximum value detection section 5 is input to the symbol data selection section 6. At this time, the maximum value of the accumulated power value is output from the symbol accumulation addition section 2 by the maximum value detection section 5. The symbol data in the slot next to the detected slot has been input.

In the symbol data selection unit 6, the point at which the maximum value detection unit 5 detects the power value as the maximum value of the symbol cumulative addition data cumulatively added by the symbol cumulative addition unit 2, ie, the previous point. The symbol cumulative addition data at the point where the cumulative power is detected as the maximum value in the slot is output to the subsequent circuit (step S1).
07).

As described above, the inside of the chip rate is divided into a plurality of timings, the reception power at each timing is calculated, and the data in the next slot is extracted at the timing when the reception power becomes the maximum, and the circuit at the subsequent stage is extracted. , The reception quality is improved.

[0016]

In the receiving circuit provided with the finger receiving section as described above, the above-mentioned 5 is based on the addition result in the slot power accumulating and adding section.
Among the complex despreading points of the point, the point at which the slot accumulated power value becomes the maximum is detected. However, when the transmitted data is a burst such as a paging channel (PCH), there is no received data. For the slot, the point where the slot cumulative power value becomes the maximum is detected at the noise level, and in the symbol cumulative addition data in the next slot, data at the point detected as the maximum value is extracted and output to the subsequent circuit. Therefore, there is a problem that an optimal complex despreading point is not selected in the next slot, and reception quality is degraded.

The present invention has been made in view of the above-mentioned problems of the technology, and aims to improve reception quality even when transmitted data is a burst like a paging channel. It is an object of the present invention to provide a receiving circuit capable of performing the above.

[0018]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an antenna and a radio unit for receiving data, and a reception unit via the antenna and a radio unit corresponding to a plurality of multipaths. A plurality of finger receiving units for despreading the data, and a receiving circuit having at least a synthesizing unit for synthesizing the data despread in the finger receiving unit, the plurality of finger receiving units, The despreading is performed by dividing the reception timing for each predetermined section into a plurality of sections, and the timing having the highest reception level is detected based on the result of the despreading. Is output.

Each of the plurality of finger receiving units determines the presence or absence of reception data based on the reception level at the timing at which the reception level is the highest, and if there is no reception data, the timing is set to the next section. It is not used for data output.

(Operation) In the present invention configured as described above, in a plurality of finger receiving sections, the reception timing for each predetermined section is divided into a plurality of sections, and the received data is despread, The timing with the highest reception level is detected based on the result of the despreading,
Since the data of the next section is output at the timing,
The reception quality is improved.

The presence or absence of received data is determined based on the reception level at the timing when the reception level is the best, and if it is determined that the reception data is present, the data of the next section is transmitted at the timing when the reception level is the best. Output, and if it is determined that there is no received data, the data of the next section is output at the current data output timing, and if the received data is a burst like a paging channel, Since the timing detection in the data is not reflected in the output of the data, the reception quality does not deteriorate when the received data is a burst like a paging channel.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a configuration example of a mobile communication system having a mobile terminal provided with a receiving circuit of the present invention.

As shown in FIG. 1, this configuration example includes a plurality of mobile terminals 10a and 10b provided with a receiving circuit of the present invention,
Base stations 20a and 20b having service areas 40a and 40b, respectively, and connected to mobile terminals 10a and 10b via wireless lines, and an exchange 30 for controlling exchange of base stations 20a and 20b. I have. In addition,
Mobile terminals 10a and 10b and base station devices 20a and 20b
It is assumed that not only two but a plurality are provided.

In the mobile communication system configured as described above, the mobile terminals 10a and 10b
a in the service area 40a of the mobile terminal 1
0a and 10b receive the service by the base station 20a, and when the mobile terminals 10a and 10b are in the service area 40b of the base station device 20b, the mobile terminals 10a and 10b
10b is served by the base station 20b.

FIG. 2 shows mobile terminals 10a, 1 shown in FIG.
FIG. 3 is a block diagram showing an embodiment of a receiving circuit provided in 0b.

As shown in FIG. 2, in the present embodiment, the antenna 11 and the radio unit 12 for receiving data and the antenna 11 and the radio unit 1 corresponding to a plurality of multipaths are provided.
A plurality of finger receiving units 13a to 13f for despreading the data received via
To 13f, a maximum ratio combining unit 14 for combining the data despread, a search engine 15 for detecting each multipath component, and a CPU 1 for controlling the finger receiving units 13a to 13f based on the detection result in the search engine 15.
6 are provided.

In the receiving circuit configured as described above, when data is received by the antenna 11 and the radio section 12, the received signal is transmitted to a plurality of finger receiving sections 13a.
13f, and thereafter, the maximum ratio combining unit 14 combines the data despread by the plurality of finger receiving units 13a to 13f, and outputs the combined data to a subsequent circuit (not shown).

Hereinafter, the above-mentioned finger receiving section will be described in detail with reference to some specific examples.

(First Embodiment) FIG. 3 is a diagram showing a first embodiment of the finger receivers 13a to 13f shown in FIG.

In this embodiment, as shown in FIG.
And data received via the radio section 12 with respect to a reference point at 16.384 MHz of -1 / 2π,-／ π,
A despreading unit 1 that performs complex despreading at five points of 0π, + ／ π, and + ／ π for each chip rate, and data that is complex despread by the despreading unit 1 for each of the five points for each symbol rate section. , A symbol power calculator 3 that converts each of the symbol data cumulatively added by the symbol accumulator 2 into a power value and outputs the power value, and a symbol power calculator 3 that outputs the symbol data. A slot power accumulator 4 for accumulating the five power values in the slot rate section; and based on the addition result in the slot power accumulator 4, the slot cumulative power value of the five complex despread points is determined to be the maximum. A maximum value detecting unit 5 for detecting a point that is a predetermined point, and a slot accumulated power value at a point detected by the maximum value detecting unit 5 as a maximum value. And a data determination unit 7 for comparing the received data with the received data based on the comparison result. A switching unit 8 for outputting a point detected as having the maximum power value, and a switching unit 8
When the point at which the power value is detected as the maximum value by the maximum value detection unit 5 is input through the symbol accumulation addition data in the symbol accumulation addition unit 2, the maximum value detection unit 5 The symbol accumulated addition data at the point where the power value is detected as the maximum value is output to a subsequent circuit (not shown).
When the point at which the power value is detected as the maximum value by the maximum value detection unit 5 via the switching unit 8 is not input, among the symbol cumulative addition data cumulatively added by the symbol cumulative addition unit 2, A symbol data selector 6 for outputting the symbol accumulated addition data at the same point as the symbol accumulated addition data output in the previous slot to the subsequent circuit.

The operation of the finger receiving unit configured as described above will be described below.

FIG. 4 is a flowchart for explaining the operation of the finger receiving section shown in FIG.

A threshold value Pth for determining the presence or absence of received data is set in the data determination unit 7 in advance (step S1). Here, at the threshold value Pth set by the data determination unit 7, if the power value of the slot cumulatively added by the slot power accumulation adding unit 4 is equal to or greater than the threshold value Pth, there is received data. Is determined.

When data is received via the antenna 11 and the radio section 12 (step S2), first, the despreading section 1
, The data received via the antenna 11 and the radio unit 12 is -384.
1 / 2π,-／ π, 0π, + ／ π, + ／ π
Are subjected to complex despreading for each chip rate (step S3).

Next, in the symbol accumulating and adding section 2, the data subjected to complex despreading in the despreading section 1 is cumulatively added for each of the above five points for each symbol rate section (step S4).

Next, in the symbol power calculator 3,
The symbol data cumulatively added by the symbol cumulative addition section 2 are converted into power values, and the five power values are output (step S5).

Next, in the slot power accumulating and adding section 4, the power values of the five points output from the symbol power calculating section 3 are cumulatively added in the slot rate section to calculate the slot power value (step S6).

Next, the maximum value detecting section 5 detects a point at which the slot cumulative power value becomes maximum among the above five complex despread points based on the addition result in the slot power cumulative adding section 4 (see FIG. 4). Step S7).

Next, the data judgment section 7 compares the threshold value Pth preset at step S1 with the slot power value Psl at the point detected at step S7 (step S8), and If Psl is greater than or equal to threshold value Pth, it is determined that there is received data. If slot power value Psl is less than threshold value Pth, it is determined that there is no received data.

If it is determined in step S8 that there is received data, the point at which the maximum value of the slot accumulated power value is detected by the maximum value detection unit 5 is input to the symbol data selection unit 6 via the switching unit 8. (Step S9).

Thereafter, when the point at which the power value is detected as the maximum value by the maximum value detection unit 5 via the switching unit 8 is input to the symbol data selection unit 6, the symbol accumulation addition unit 2 performs cumulative addition. Among the obtained symbol cumulative addition data, the symbol cumulative addition data at the point where the power value is detected as the maximum value by the maximum value detection unit 5 is output to the subsequent circuit, and the maximum value detection is performed via the switching unit 8. Part 5
In the case where the point at which the power value is detected as the maximum value is not input, the same point as the symbol accumulated addition data output in the previous slot in the symbol accumulated addition data accumulated by the symbol accumulation adding unit 2 is used. Is output to the subsequent circuit (step S1).
0).

(Second Embodiment) In the above-described first embodiment, the presence / absence of reception data is determined by comparing the power value obtained by cumulative addition of the slot rate section with a predetermined threshold value. Although the determination is made, the presence or absence of the received data can be determined by comparing the power value added for each symbol with the threshold value.

FIG. 5 shows the finger receiving unit 1 shown in FIG.
It is a figure which shows 2nd Embodiment of 3a-13f.

In this embodiment, as shown in FIG.
And data received via the radio section 12 with respect to a reference point at 16.384 MHz of -1 / 2π,-／ π,
A despreading unit 1 that performs complex despreading at five points of 0π, + ／ π, and + ／ π for each chip rate, and data that is complex despread by the despreading unit 1 for each of the five points for each symbol rate section. , A symbol power calculator 3 that converts each of the symbol data cumulatively added by the symbol accumulator 2 into a power value and outputs the power value, and a symbol power calculator 3 that outputs the symbol data. Based on the five power values, the maximum value detection unit 25 detects the point where the symbol power value becomes maximum among the five complex despread points, and the maximum value detection unit 25 detects the maximum value. The symbol power value at the point is compared with a predetermined threshold value, and a data determination unit 27 that determines whether or not there is received data based on the comparison result. Only when it is determined that there is data, the switching unit 28 outputs a point where the symbol power value is detected as the maximum by the maximum value detection unit 25, and the power value is detected by the maximum value detection unit 25 via the switching unit 28. When the point at which the power value is detected as the maximum value in the symbol accumulated addition data accumulated by the symbol accumulation The symbol accumulative addition data is output to a circuit (not shown) at the subsequent stage. If the point at which the power value is detected as the maximum value by the maximum value detection unit 25 via the switching unit 28 is not input, the symbol accumulative addition unit 2 Of the symbol cumulative addition data obtained by cumulative addition at the same point as the symbol cumulative addition data output by the previous symbol, the symbol cumulative addition data being output to the subsequent circuit. And a Rudeta selector 6.

Hereinafter, the operation of the finger receiving section configured as described above will be described.

FIG. 6 is a flowchart for explaining the operation of the finger receiving section shown in FIG.

In the data determination section 27, a threshold value Pth for determining the presence or absence of received data is set in advance (step S11). Here, with respect to the threshold value Pth set by the data determination unit 27, if the symbol power value calculated by the symbol power calculation unit 3 is equal to or larger than the threshold value Pth, it is determined that there is received data. Things.

When data is received via the antenna 11 and the radio unit 12 (step S12), first, in the despreading unit 1, the data received via the antenna 11 and the radio unit 12 is transmitted to the reference point. 16.384 MHz -1 / 2π, -−１π, 0π, + ／ π, + ／
Complex despreading is performed on the five points of π for each chip rate (step S13).

Next, in the symbol accumulating and adding unit 2, the data subjected to complex despreading in the despreading unit 1 is cumulatively added for each of the above five points for each symbol rate section (step S14).

Next, in the symbol power calculator 3,
The symbol data cumulatively added by the symbol cumulative addition unit 2 are converted into power values, and the five power values are output (step S15).

Next, in the maximum value detecting section 25, based on the five power values output from the symbol power calculating section 3, the point having the maximum symbol power value among the five complex despread points is determined. It is detected (step S16).

Next, in the data determination section 7, the threshold value Pth preset in step S11 and the threshold value P1
The symbol power value Psn at the point detected in step 6 is compared with the symbol power value Psn (step S17). If the symbol power value Psn is equal to or greater than the threshold value Pth, it is determined that there is received data, and the symbol power value Psn is If it is less than the threshold value Pth, it is determined that there is no received data.

If it is determined in step S17 that there is received data, the point where the maximum symbol power value is detected by the maximum value detecting section 25 is input to the symbol data selecting section 6 via the switching section 28 ( Step S1
8).

Thereafter, when a point at which the power value is detected as the maximum value by the maximum value detection unit 25 via the switching unit 28 is input to the symbol data selection unit 6, the symbol accumulation addition unit 2 performs cumulative addition. Among the obtained symbol cumulative addition data, the symbol cumulative addition data at the point where the power value is detected as the maximum value by the maximum value detection unit 25 is output to the subsequent circuit, and the maximum value detection is performed via the switching unit 28. When the point at which the power value is detected as the maximum value by the unit 25 is not input, the symbol cumulative addition data output by the previous symbol out of the symbol cumulative addition data cumulatively added by the symbol cumulative addition unit 2 The symbol cumulative addition data at the same point is output to a subsequent circuit (step S19).

(Third Embodiment) In the above-described first and second embodiments, the power value or the power value for each symbol accumulated in the slot rate section and the predetermined threshold value are determined. Although the presence / absence of the received data is determined by comparison, the S / N ratio of the received data is calculated, the calculated result is compared with a threshold value, and the S / N ratio of the received data is determined.
If the / N ratio is equal to or greater than the threshold, it can be determined that there is received data.

FIG. 7 shows the finger receiving unit 1 shown in FIG.
It is a figure showing 3a-3f of 3rd Embodiment.

In this embodiment, as shown in FIG.
And data received via the radio section 12 with respect to a reference point at 16.384 MHz of -1 / 2π,-／ π,
A despreading unit 1 that performs complex despreading at five points of 0π, + ／ π, and + ／ π for each chip rate, and data that is complex despread by the despreading unit 1 for each of the five points for each symbol rate section. A symbol accumulator 2 for accumulating the symbol data, a symbol S / N ratio calculator 33 for respectively calculating and outputting the S / N ratio of the received data from the symbol data accumulatively added by the symbol accumulator 2, and a symbol S
The slot S / N ratio accumulative adder 34 for accumulating the S / N ratios of the five points output from the / N ratio calculator 33 in the slot rate section cumulatively, and the slot S / N ratio accumulative adder 34 based on the addition result. A maximum value detector 35 for detecting a point at which the slot cumulative S / N ratio becomes maximum among the five complex despread points, and a slot cumulative S at a point detected by the maximum value detector 35 as the maximum value. / N ratio and a predetermined threshold value, and a data determination unit 37 that determines whether or not there is received data based on the comparison result;
Only when it is determined that there is received data, the switching unit 38 outputs a point at which the maximum value of the slot cumulative S / N ratio is detected by the maximum value detection unit 35, and the maximum value detection unit via the switching unit 38 When the point at which the S / N ratio is detected as the maximum value at 35 is input, the S / N ratio at the maximum value detection unit 35 of the symbol accumulated addition data accumulated by the symbol accumulation addition unit 2 is input. Is output to a subsequent circuit (not shown) at the point where is detected as the maximum value.
When the point where the N ratio is detected as the maximum value is not input,
A symbol data selector 6 that outputs, to the subsequent circuit, the symbol cumulative addition data at the same point as the symbol cumulative addition data output in the previous slot among the symbol cumulative addition data cumulatively added by the symbol cumulative addition unit 2. It is composed of

The operation of the finger receiving unit configured as described above will be described below.

FIG. 8 is a flowchart for explaining the operation of the finger receiving section shown in FIG.

A threshold value Pth for determining the presence or absence of received data is set in advance in the data determination unit 37 (step S21). Here, with respect to the threshold value Pth set by the data determination unit 37, when the S / N ratio of the slots cumulatively added by the slot S / N ratio cumulative addition unit 34 is equal to or greater than the threshold value Pth. , Received data is determined to be present.

When data is received via the antenna 11 and the radio unit 12 (step S22), the data received via the antenna 11 and the radio unit 12 in the despreading unit 1 16.384 MHz -1 / 2π, -−１π, 0π, + ／ π, + ／
Complex despreading is performed on the five points of π for each chip rate (step S23).

Next, in the symbol accumulating and adding unit 2, the data subjected to complex despreading in the despreading unit 1 is cumulatively added for each of the above five points for each symbol rate section (step S24).

Next, the symbol S / N ratio calculation section 33 calculates the S / N ratio of the received data from the symbol data cumulatively added by the symbol cumulative addition section 2, respectively.
The S / N ratios of the five points are output (step S25).

Next, in the slot S / N ratio accumulative addition unit 34, the 5 output from the symbol S / N ratio calculation unit 33 is output.
The S / N ratios of the points are cumulatively added in the slot rate section, and the slot cumulative S / N ratio is calculated (step S26).

Next, in the maximum value detecting section 35, based on the addition result in the slot S / N ratio accumulating and adding section 34, the slot accumulated S / N among the five complex despread points is used.
The point where the ratio becomes maximum is detected (step S27).

Next, in the data judgment section 37, the threshold value Pth preset in step S21 and the
Slot cumulative S / N ratio P at point detected at 27
sl (step S28), and the slot accumulation S /
If the N ratio Psl is greater than or equal to the threshold value Pth, it is determined that there is received data. If the slot cumulative S / N ratio Psl is less than the threshold value Pth, it is determined that there is no received data. .

If it is determined in step S 28 that there is received data, the point at which the maximum S / N ratio is detected by the maximum value detector 35 is input to the symbol data selector 6 via the switch 38. (Step S2
9).

Thereafter, when a point at which the S / N ratio is detected as the maximum value by the maximum value detection unit 35 via the switching unit 38 is input to the symbol data selection unit 6, the symbol accumulation addition unit 2 Among the cumulatively added symbol cumulative addition data, the symbol cumulative addition data at the point where the S / N ratio is detected as the maximum value by the maximum value detection unit 35 is output to the subsequent circuit, and is also transmitted through the switching unit 38. If the point at which the S / N ratio is detected as the maximum value by the maximum value detection unit 35 is not input, the symbol accumulation addition data accumulated by the symbol accumulation addition unit 2 is output in the previous slot. The accumulated symbol data at the same point as the accumulated symbol accumulated data is output to the subsequent circuit (step S30).

(Fourth Embodiment) In the third embodiment described above, the S / N obtained by cumulative addition of the slot rate section is used.
Although the presence / absence of received data is determined by comparing the ratio with a predetermined threshold, the presence / absence of received data is determined by comparing the S / N ratio added for each symbol with the threshold. It can also be determined.

FIG. 9 shows the finger receiving unit 1 shown in FIG.
It is a figure which shows 4a of 3a-13f.

In this embodiment, as shown in FIG.
And data received via the radio section 12 with respect to a reference point at 16.384 MHz of -1 / 2π,-／ π,
A despreading unit 1 that performs complex despreading at five points of 0π, + ／ π, and + ／ π for each chip rate, and data that is complex despread by the despreading unit 1 for each of the five points for each symbol rate section. A symbol accumulator 2 for accumulating the symbol data, a symbol S / N ratio calculator 33 for respectively calculating and outputting the S / N ratio of the received data from the symbol data accumulatively added by the symbol accumulator 2, and a symbol S
A maximum value detector 45 for detecting a point at which the symbol S / N ratio becomes maximum among the five complex despread points based on the five S / N ratios output from the / N ratio calculator 33; A data determination unit that compares the symbol S / N ratio at the point detected as the maximum value by the maximum value detection unit 45 with a predetermined threshold value and determines whether there is received data based on the comparison result. A switching unit 48 that outputs a point at which the maximum value detection unit 45 detects the symbol S / N ratio as the maximum only when the data determination unit 47 determines that there is received data; Via the maximum value detection unit 45 via S
When the point where the / N ratio is detected as the maximum value is input,
Of the symbol cumulative addition data cumulatively added by the symbol cumulative addition section 2, the symbol cumulative addition data at the point where the S / N ratio is detected as the maximum value by the maximum value detection section 45 is output to a subsequent circuit (not shown). If the point at which the S / N ratio is detected as the maximum value by the maximum value detection unit 45 via the switching unit 48 is not input, the symbol accumulation addition data of the symbol accumulation addition unit 2 The symbol data selecting section 6 outputs the symbol cumulative addition data at the same point as the symbol cumulative addition data output by the previous symbol to the subsequent circuit.

Hereinafter, the operation of the finger receiving section configured as described above will be described.

FIG. 10 is a flowchart for explaining the operation of the finger receiving section shown in FIG.

In the data determination section 47, a threshold value Pth for determining whether or not there is received data is set in advance (step S31). Here, as for the threshold value Pth set by the data determination unit 47, the symbol S / N ratio calculated by the symbol S / N ratio calculation unit 33 is equal to the threshold value Pth.
If it is not less than th, it is determined that there is received data.

When data is received via the antenna 11 and the radio unit 12 (step S32), the data received via the antenna 11 and the radio unit 12 is first demultiplexed by the despreading unit 1 with respect to a reference point. 16.384 MHz -1 / 2π, -−１π, 0π, + ／ π, + ／
Complex despreading is performed for each of the five points of π for each chip rate (step S33).

Next, in the symbol accumulating and adding section 2, the data subjected to complex despreading in the despreading section 1 is cumulatively added for each of the above five points for each symbol rate section (step S34).

Next, the symbol S / N ratio calculating section 33 calculates the S / N ratio of the received data from the symbol data cumulatively added by the symbol cumulative adding section 2, respectively.
The S / N ratios at the five points are output (step S35).

Next, in the maximum value detecting section 45, based on the S / N ratios of the five points output from the symbol S / N ratio calculating section 33, the symbol S / N of the five complex despread points is used.
The point at which the N ratio becomes maximum is detected (step S36).

Next, in the data judgment section 47, the threshold value Pth preset in step S31 and the
The symbol S / N ratio Psn at the point detected at 36 is compared (step S37), and the symbol S / N ratio Psn is determined.
Is greater than or equal to the threshold value Pth, it is determined that there is received data. If the symbol S / N ratio Psn is less than the threshold value Pth, it is determined that there is no received data.

If it is determined in step S37 that there is received data, the maximum value detector 45 detects the symbol S /
The point detected as having the maximum N ratio is input to the symbol data selection unit 6 via the switching unit 48 (step S3).
8).

Thereafter, in the symbol data selection unit 6, when a point at which the S / N ratio is detected as the maximum value by the maximum value detection unit 45 via the switching unit 48 is input, the symbol accumulation addition unit 2 Among the cumulatively added symbol cumulatively added data, the symbol cumulatively added data at the point where the S / N ratio is detected as the maximum value by the maximum value detecting unit 45 is output to the subsequent circuit, and is also transmitted through the switching unit 48. If the point at which the S / N ratio is detected as the maximum value by the maximum value detection unit 45 is not input, the symbol is output by the previous symbol of the symbol cumulative addition data cumulatively added by the symbol cumulative addition unit 2. The symbol accumulated data at the same point as the symbol accumulated added data is output to the subsequent circuit (step S39).

In the first to fourth embodiments described above, the inside of the chip rate is divided into four parts, each of which is -384π,-／ of 16.384 MHz.
Despreading is performed for five points of π, 0π, + ／ π, and + ／ π, and the reception data of the next slot at the point having the highest reception level among the five points is output to the subsequent circuit. One data can be divided into four and the same operation as described above can be performed.

[0084]

As described above, in the present invention,
In the plurality of finger receiving units, the reception timing for each predetermined section is divided into a plurality of parts to perform despreading of the received data, and the timing having the best reception level is detected based on the result of the despreading. Since the data of the next section is output at the timing, the reception quality can be improved.

The presence or absence of received data is determined based on the reception level at the timing when the reception level is the highest, and if it is determined that the reception data is present, the data of the next section is transmitted at the timing when the reception level is the highest. Output, when it is determined that there is no received data, when the data of the next section is output at the timing of outputting the current data, the received data was a burst like a paging channel. In this case, since the timing detection in the data is not reflected in the output of the data, the reception quality can be improved even when the received data is a burst like a paging channel.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a mobile communication system having a mobile terminal provided with a receiving circuit of the present invention.

FIG. 2 is a block diagram showing an embodiment of a receiving circuit provided in the mobile terminal shown in FIG.

FIG. 3 is a diagram illustrating a first embodiment of the finger receiving unit illustrated in FIG. 2;

FIG. 4 is a flowchart for explaining the operation of the finger receiving unit shown in FIG. 3;

FIG. 5 is a diagram illustrating a second embodiment of the finger receiving unit illustrated in FIG. 2;

FIG. 6 is a flowchart for explaining the operation of the finger receiving unit shown in FIG. 5;

FIG. 7 is a diagram illustrating a third embodiment of the finger receiving unit illustrated in FIG. 2;

FIG. 8 is a flowchart for explaining the operation of the finger receiver shown in FIG. 7;

FIG. 9 is a diagram illustrating a fourth embodiment of the finger receiving unit illustrated in FIG. 2;

FIG. 10 is a flowchart for explaining the operation of the finger receiver shown in FIG. 9;

FIG. 11 is a block diagram illustrating a configuration example of a finger receiving unit that the present inventors are currently experimentally studying.

FIG. 12 is a flowchart illustrating an operation of the finger receiving unit illustrated in FIG. 11;

FIG. 13 is a diagram illustrating an example of received data for describing an operation of the finger receiving unit illustrated in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Despreading part 2 Symbol accumulation addition part 3 Symbol power calculation part 4 Slot power accumulation addition part 5,25,35,45 Maximum value detection part 6 Symbol data selection part 7,27,37,47 Data judgment part 8,28, 38, 48 determination unit 10a, 10b mobile terminal 11 antenna 12 radio unit 13a to 13f finger reception unit 14 maximum ratio combining unit 15 search engine 16 CPU 20a, 20b base station apparatus 30 exchange 33 symbol S / N ratio calculation unit 34 slot S / N ratio cumulative adder 40a, 40b Service area

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B 1/69-1/713 H04J 13/00-13/06 H04B 7/02 H04B 7/08 H04B 7 / 26

Claims (1)

(57) [Claims] An antenna and a radio unit for receiving data, a plurality of finger receiving units for despreading data received via the antenna and the radio unit corresponding to a plurality of multipaths, A receiving unit having at least a synthesizing unit for synthesizing the data despread by the finger receiving unit. The despreading is performed, and based on the result of the despreading, a timing having the highest reception level is detected .
The presence or absence of received data based on the received level
If there is received data, the data of the next section is
Data, and if there is no received data, the
A receiving circuit that does not use the signal for outputting data in the next section .