JP2009171111A - Receiver, mobile communication system, and correlated calculation resource control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive receiver capable of reducing correlated calculation resources. <P>SOLUTION: The receiver has a receiving part 10 for receiving an information signal, including a first reference signal and a searcher part 21. The searcher part 21 is provided with: a window assignment part for assigning at least one search window for defining a time width for enabling detection of reception timing in each path of the information signals to be received by the receiving part 10 through a multipath to each call from a transmitter; a correlated calculation part which has a plurality of correlated calculation resources, and in which the correlated calculation resources to be used for correlating a received signal with a second reference signal, corresponding to the first referential signal, are assigned from among a plurality of correlated calculation resources; and a correlated calculation resource control part for dynamically controlling assignment of the correlated calculation resources in the correlated calculation part, according to the time width of the search window assigned by the window assignment part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a receiving apparatus used for mobile communication.

  Mobile communication systems that employ systems such as CDMA (Code Division Multiple Access) and W-CDMA (Wideband CDMA) are known. In this type of mobile communication system, a signal transmitted from the transmission side arrives at the reception side through various transmission paths (multipaths) due to reflection and diffraction at a building or the like. For this reason, the receiving apparatus generally performs RAKE combining that individually detects and combines signals arriving via such multipath. In this rake synthesis, multi-pal is detected by correlation calculation, and a path search is performed to acquire the reception timing in each path.

  Patent Document 1 discloses a receiving device that detects multipal by correlation calculation. The receiving device includes a searcher unit that detects multipaths by correlation calculation, a finger unit that despreads each detected path signal, and a decoder unit that decodes a received signal from a signal obtained by synthesizing multipath finger outputs; Is provided. For the correlation calculation in the searcher unit, a plurality of correlation calculation resources such as a correlator are used.

  FIG. 9 shows the configuration of the searcher unit as a related technique. Referring to FIG. 9, the searcher unit 120 includes a delay profile generation unit 122, a path detection processing unit 124, and a window allocation unit 124.

  The input signal 2 a supplied from the reception unit to the searcher unit 120 is supplied to the delay profile generation unit 122. The input signal 2a is a signal in which a signal (call) transmitted from at least one transmission device (mobile body) is received through a multipath. In the transmission apparatus, an information signal in which a known pilot signal or code as a reference signal is multiplexed with a signal (data) to be transmitted is transmitted.

  The delay profile generation unit 122 correlates a signal delayed in a stepwise manner with respect to the input signal 2a and a known pilot signal (same as the pilot signal used on the transmission side), and outputs the I phase and Q phase. A correlation value, which is a vector quantity consisting of Then, the delay profile generation unit 122 supplies the path detection processing unit 123 with the delay profile 2b obtained by converting the calculated correlation value into a power value. The correlation value is calculated in the time range of the search window supplied from the window allocation unit 124.

  The path detection processing unit 123 detects a multipath from the delay profile 2b supplied from the delay profile generation unit 122. In this multipath detection, for example, a plurality of paths are selected in descending order of power value in the delay profile 2b. The path detection processing unit 23 supplies path information 2c (path timing) indicating the delay time of the selected path to the window allocation unit 124 and the finger unit 21.

  The window allocation unit 124 determines a search window based on the path information 2c from the path detection processing unit 23. Here, the search window defines a time width (time position) in which the reception timing of each signal received through the multipath can be detected. The determined search window information is supplied from the window assignment unit 124 to the delay profile generation unit 122 as window information 2d. The finger unit 21 despreads the signal of each path detected by the path detection processing unit 123 based on the path information 2c.

  In the searcher unit 122 configured as described above, the delay profile generation unit 122 has a plurality of correlation calculation resources, and a certain number of correlation calculation resources are allocated to each search window.

FIG. 10 is a schematic diagram showing how correlation operation resources are allocated. In this example, six correlation calculation resources are allocated to each of the n search windows Win # 0 to Win # n-1. Thus, in the delay profile generation unit 122, the number of correlation calculation resources allocated to the search window is fixed.
JP 2005-503683 A

  The time width of the search window changes depending on the change in the multipath environment, the influence of fading, the movement of the moving body, and the moving speed. For this reason, in the above-described receiving apparatus, the number of correlation calculation resources allocated to the search window is fixed to a number (maximum number) that can correspond to the largest time width that the search window can take. The

  However, when the number of correlation calculation resources allocated is fixed to the maximum number, correlation calculation resources are excessively allocated to a search window having a small time width. For example, in the example shown in FIG. 10, 6 correlation calculation resources are allocated to a search window in which correlation calculation can be performed with four correlation calculation resources, so that two correlation calculation resources are excessively allocated. Will be. Normally, in mobile communication, a situation in which the maximum six correlation calculation resources are allocated to all the search windows of each call does not occur. Therefore, excessive allocation of correlation calculation resources is performed for some search windows. Thus, since the above-described receiving apparatus has a configuration in which correlation calculation resources are allocated excessively, it is necessary to prepare extra correlation calculation resources, and the cost of the apparatus increases correspondingly.

  An object of the present invention is to provide a low-cost receiving apparatus, mobile communication system, and correlation calculation resource control method capable of solving the above-described problems and reducing correlation calculation resources.

In order to achieve the above object, the receiving apparatus of the present invention provides:
A receiving unit for receiving an information signal including a first reference signal;
A window allocation unit that allocates at least one search window that defines a time width in which the reception timing of each of the information signals received by the reception unit through multipaths can be detected for each call from the transmission device When,
A plurality of correlation calculation resources, the correlation calculation resources used to correlate the information signal received by the receiving unit and the second reference signal corresponding to the first reference signal A correlation calculation unit allocated from a correlation calculation resource;
A correlation calculation resource control unit that dynamically controls allocation of correlation calculation resources in the correlation calculation unit in accordance with a time width of a search window allocated by the window allocation unit.

  A mobile communication system of the present invention includes the above-described receiving device and a mobile terminal that transmits an information signal including a reference signal to the receiving device by wireless communication.

The correlation calculation resource control method of the present invention is a correlation calculation resource control method for a receiving apparatus having a plurality of correlation calculation resources,
A first step of allocating, from the plurality of correlation calculation resources, a correlation calculation resource used to correlate a received signal including a first reference signal and a second reference signal corresponding to the first reference signal; ,
A second step of allocating at least one search window for defining a time width in which the reception timing of each of the received signals received through the multipath can be detected in each path;
And a third step of dynamically controlling the allocation of correlation calculation resources in the first step according to the time width of the search window allocated in the second step.

  According to the present invention, since correlation calculation resources are dynamically allocated according to the time width of the search window, it is necessary for the entire apparatus as compared with the case where the number of correlation calculation resources allocated to the search window is fixed to the maximum number. The number of correlation calculation resources can be reduced.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a receiving apparatus according to an embodiment of the present invention. Referring to FIG. 1, the receiving device is a receiving device used in a mobile communication system such as W-CDMA, for example, and its main part includes a receiving unit 10 and a demodulating unit 20.

  The receiving unit 10 receives a radio signal from a transmission side (for example, a mobile terminal). The radio signal is an information signal obtained by multiplexing a known pilot signal (or spreading code), which is a reference signal, with a signal (data) to be transmitted. As an information signal, for example, there is a signal obtained by multiplying (spreading) an information signal made up of bit data by a spreading code made up of chip data. The receiving unit 10 performs frequency modulation on the baseband signal of the received signal. The frequency-modulated signal is supplied from the receiving unit 10 to the demodulating unit 20 as the input signal 1a.

  The demodulating unit 20 includes a searcher unit 21, a finger unit 22, and a decoder unit 23. The searcher unit 21 performs a correlation calculation between the input signal 1a and a known pilot signal, and notifies the finger unit 22 of a highly correlated delay position (reception timing). The finger unit 22 performs despreading and rake combining on the input signal 1 a based on the delay position notified from the searcher unit 21 and notifies the decoder unit 23 of the rake combining result. The decoder unit 23 decodes the received signal from the rake synthesized symbol information.

  Next, the structure of the searcher part 21 which is the characteristic part of the receiver of this embodiment is demonstrated concretely.

  FIG. 2 is a block diagram showing a configuration of a searcher unit of the receiving apparatus shown in FIG. Referring to FIG. 2, the searcher unit 21 includes a delay profile generation unit 210, a path detection processing unit 211, a window allocation unit 212, and a correlation calculation resource control unit 213.

  The delay profile generation unit 210 includes a correlation calculation unit including a plurality of correlation calculation resources including a correlator and a code generator. The correlation calculation unit can allocate correlation calculation resources to a plurality of search windows. The correlation calculation unit includes a fixed area in which a certain number of correlation calculation resources are secured for each search window, and a share area in which correlation calculation resources are allocated to a search window in which the allocation of correlation calculation resources in the fixed area is insufficient. And have.

  In the delay profile generation unit 210, the correlation calculation resource is allocated to the search window in the correlation calculation unit in accordance with the resource determination information 1e from the correlation calculation resource control unit 213. Using this allocated correlation calculation resource, a correlation between the signal delayed in a stepwise manner with respect to the input signal 1a and a known pilot signal (same as the pilot signal used on the transmission side) is obtained, and the I phase and A correlation value, which is a vector quantity composed of the Q phase, is calculated. The delay profile generation unit 210 supplies the path detection processing unit 211 with a delay profile 1b obtained by converting the calculated correlation value into a power value.

  The path detection processing unit 211 detects a multipath from the delay profile 1b supplied from the delay profile generation unit 210. In this multipath detection, for example, a plurality of paths are selected in descending order of power value in the delay profile 1b. The path detection processing unit 211 supplies path information 1c (path timing) indicating the delay time of the selected path to the window allocation unit 212 and the finger unit 22.

  The window allocation unit 212 sets at least one search window that defines a time width in which the reception timing of each information signal received by the receiving unit 10 through the multipath can be detected for each call from the transmission side. Assign to. Specifically, the window allocation unit 212 determines a search window based on the path information 1c from the path detection processing unit 211, and determines the number of correlation calculation resources necessary for the correlation calculation in the search window. The decision information is supplied as window information 1d from the window allocation unit 212 to the correlation calculation resource control unit 213. The window information 1d includes a time width (delay position information) related to the determined search window and the number of correlation calculation resources necessary for the correlation calculation.

  The correlation calculation resource control unit 213 manages the allocation of correlation calculation resources in each area of the correlation calculation unit in the delay profile generation unit 210 and is determined by the window allocation unit 212 based on the window information 1d from the window allocation unit 212. The correlation calculation resource used in the selected search window is determined. Information on the determined correlation calculation resource is supplied from the correlation calculation resource control unit 213 to the delay profile generation unit 210 as resource determination information 1e.

  Next, management of correlation calculation resources by the correlation calculation resource control unit 213 will be specifically described.

  The correlation calculation resource control unit 213 includes a correlation calculation resource setting information storage unit for managing the allocation of correlation calculation resources in each area of the correlation calculation unit. FIG. 3 shows an example of correlation calculation resource setting information stored in the correlation calculation resource setting information storage unit.

  The correlation calculation resource setting information shown in FIG. 3 is for managing fixed area management information for managing the allocation of correlation calculation resources in the fixed area of the correlation calculation unit and for allocating correlation calculation resources in the share area of the correlation calculation unit. And share area management information.

  The fixed area management information is information on correlation calculation resources currently allocated to the search window in the fixed area. In the example shown in FIG. 3, two correlation calculation resources are allocated to each of the n search windows Win # 0 to Win # n-1. This indicates that the number of correlation operation resources allocated to the search window in the fixed area is fixed to two.

  The share area management information is information on correlation calculation resources currently allocated to the search window in the share area. In the share area, a shortage of correlation calculation resources are allocated to a search window in which the number of correlation calculation resources is insufficient with only the correlation calculation resources allocated in the fixed area. In the example shown in FIG. 3, the number of correlation calculation resources that are insufficient only by the allocation of correlation calculation resources in the fixed area is allocated to each of the search windows Win # 0 to Win # n-1. For example, four correlation calculation resources are allocated to the search window Win # 0, and two correlation calculation resources are allocated to the search window Win # 1. This indicates that the correlation calculation resource control unit 213 dynamically allocates the correlation calculation resource in the share area according to the time width of the search window. In the fixed area management information and the share area management information, available correlation calculation resources that are not currently assigned to the search window are managed by identification information such as “not use”, for example.

  The position information (address information on the memory) of each block of the fixed area management information is associated with the position information (identification information) of the correlation calculation resource in the fixed area of the correlation calculation unit. Further, the position information (address information on the memory) of each block of the share area management information is associated with the position information (identification information) of the correlation calculation resource in the share area of the correlation calculation unit. Based on the correspondence information, the correlation calculation resource control unit 213 controls the allocation of correlation calculation resources in the delay profile generation unit 210.

  Next, a specific configuration of the delay profile generation unit 210 will be described.

FIG. 4 is a block diagram illustrating specific configurations of the correlation calculation resource control unit 213 and the delay profile generation unit 210. Referring to FIG. 4, the correlation calculation unit of the delay profile generation unit 210 includes n correlation calculation resources 1 ₁ to 1 _n , a selection circuit 4, and m correlators 5 _{1 to} 5 _m .

The correlation calculation resources 1 ₁ to 1 _n are fixed area correlation calculation resources, and all have the same configuration. The number of correlation calculation resources 1 ₁ to 1 _n corresponds to the number of search windows that can be set simultaneously. The case of the example shown in FIG. 3, the n-number of search window settings are possible, the number of correlation calculation resource 1 ₁ to 1 _n are also set to n pieces.

Correlation calculation resource 1 ₁ is intended to operate in accordance with instructions from the correlation calculation resource control unit 213 includes a code generator 2 and the correlator 3. The code generator 2 generates a known pilot signal (or spreading code) that is a reference signal, and supplies the generated signal with a certain delay to the correlator 3. The correlator 3 correlates the pilot signal supplied from the code generator 2 and the input signal 1a from the receiving unit 10 and outputs a correlation value.

In the example shown in FIG. 4, for the sake of convenience, there is only _one correlator 3 for the correlation calculation resource 11. ). Here, the minimum number of correlation calculation resources means the minimum number of correlation calculation resources under the condition that call disconnection does not occur. For example, the case of the example shown in FIG. 3, the number of correlation calculation resources previously reserved for the search window is two, the number of correlators 3 correlation calculation resource 1 ₁ becomes two. In the case of having a plurality of correlators 3, the correlators 3 are connected in parallel, and the outputs of the code generator 2 and the receiving unit 10 are supplied to the correlators 3. However, the code generator 2 gives a delay to the signal supplied to each correlator 3. The magnitude of the delay added to the signal supplied to each correlator 3 is such that the signal obtained by delaying the input signal 1a in a stepwise manner can be correlated with a known pilot signal. It is a size.

The correlators 5 _{1 to} 5 _m are correlation calculation resources in the share area, and are connected in common with each of the correlation calculation resources ₁₁ to 1 _n via the selection circuit 4. In the selection circuit 4, the connection between the correlators 5 _{1 to} 5 _m and the correlation calculation resources 1 ₁ to 1 _n is selectively performed according to the control signal from the correlation calculation resource control unit 213.

The correlation calculation resource control unit 213 includes a correlation calculation resource setting information storage unit 213a for managing the allocation status of the correlation calculation resources 1 ₁ to 1 _n in the fixed area and the correlators 5 _{1 to} 5 _{m in} the share area. In the correlation calculation resource setting information storage unit 213a, for example, the correlation calculation resource setting information illustrated in FIG. 3 is stored.

The correlation calculation resource control unit 213 uses the correlation calculation resource setting information storage unit 213a to allocate the fixed area correlation calculation resources 1 ₁ to 1 _n and the share area correlators 5 _{1 to} 5 _{m in} the delay profile generation unit 210. Manage the situation.

Further, the correlation calculation resource control unit 213 refers to the correlation calculation resource setting information storage unit 213a based on the window information 1d from the window allocation unit 212, and uses the correlation used in the search window determined by the window allocation unit 212. Determine computing resources. Then, control of the operation of the code generator and the correlator 5 _{1 to} 5 _m and the correlation operation resources 1 ₁ to 1 _n in the selection circuit 4 are performed so that the correlation operation can be performed with the determined correlation operation resource. Control connection between the two.

For example, in the example shown in FIG. 3, the correlation calculation resource control unit 213, the search window as a correlation calculation resources used by Win # 0, correlators 51 _to the correlation calculation resources 1 ₁ and share areas of fixed area Select 5 and ₂ . Here, the correlation calculation resource 1 ₁ is provided with two correlators 3, the correlation calculation resource control unit 213 counts as two correlation calculation resources. Correlation calculation resource control unit 213 controls the selection circuit 4, to connect the correlator 5 ₁ to 5 _second correlation calculation resources 1 ₁ and share areas of the fixed area. Thus, as the correlation calculation resources used by search window Win # 0, a correlation calculation resources 1 ₁ code generator 2 and two correlators 3, so that the assigned correlator 5 ₁ to 5 ₂ . In this case, the correlators of the two correlators 3 and the correlators 5 _{1 to} 5 ₂ are connected in parallel, and the code generator 2 supplies pilot signals delayed in stages to the correlators. As a result, each correlator correlates a signal obtained by delaying the input signal 1a stepwise with a known pilot signal.

  The delay profile generation unit 210 generates a delay profile based on the correlation value from each correlator. The generated delay profile is supplied to the path detection processing unit 211 as the delay profile 1b.

  Next, the operation of the searcher unit 21 will be specifically described.

  FIG. 5 is a sequence diagram showing the operation of searcher unit 21 shown in FIG. First, the delay profile generation unit 22 allocates correlation calculation resources in the fixed area and the share area of the correlation calculation unit according to the resource determination information 1e from the correlation calculation resource control unit 213. At this time, since the correlation calculation resource control unit 213 is not supplied with the window information 1d from the window allocation unit 212, the correlation calculation resource control unit 213 selects a predetermined correlation calculation resource in each of the fixed area and the share area. Resource determination information 1e to be supplied to the delay profile generation unit 22. At the same time, the correlation calculation resource control unit 213 performs an update process for reflecting the allocation of the correlation calculation resource by the resource determination information 1e in the correlation calculation resource setting information stored in the correlation calculation resource setting information storage unit. Here, the predetermined correlation calculation resource is, for example, a correlation calculation resource given in advance as a default, and includes two correlation calculation resources in the fixed area and at least one correlation calculation resource in the share area. The number of predetermined correlation calculation resources can be set as appropriate, but it is desirable to set the maximum number to cover the possible range of the search window.

  In the delay profile generation unit 22, the correlation between the input signal 1a and the known pilot signal is obtained by the correlation calculation resource in the fixed area and the share area allocated according to the resource determination information 1e from the correlation calculation resource control unit 213. A correlation value, which is a vector quantity composed of the I phase and the Q phase, is calculated. Then, the delay profile generation unit 22 supplies the path detection processing unit 211 with the delay profile 1b obtained by converting the calculated correlation value into a power value.

  Next, the path detection processing unit 211 generates path information 2c based on the delay profile 1b from the delay profile generation unit 22, and notifies the generated path information 2c to the finger unit 21 and the window allocation unit 24.

  Next, the window allocation unit 24 determines a search window based on the path information 2c from the path detection processing unit 211, and determines the number of correlation calculation resources necessary for correlation calculation in the search window. Then, the window allocation unit 24 supplies the correlation calculation resource control unit 213 with window information 1d including the determined time width (delay position information) of the search window and the number of correlation calculation resources necessary for the correlation calculation.

  Next, the correlation calculation resource control unit 213 determines a correlation calculation resource to be used in each of the fixed area and the share area based on the window information 1d from the window allocation unit 24. Then, the correlation calculation resource control unit 213 supplies the resource determination information 1e for selecting the determined correlation calculation resource to the delay profile generation unit 22. At the same time, the correlation calculation resource control unit 213 performs an update process for reflecting the allocation of the correlation calculation resource by the resource determination information 1e in the correlation calculation resource setting information stored in the correlation calculation resource setting information storage unit.

  In the delay profile generation unit 22, the correlation value is calculated using the correlation calculation resources in the fixed area and the share area assigned according to the resource determination information 1 e, and the delay profile 1 b is generated by converting the calculated correlation value into a power value. The delay profile 1b is supplied to the path detection processing unit 211.

  By repeating the above procedure, a plurality of search windows are assigned to each call from the transmission side. Then, a minimum correlation calculation resource is allocated to each search window in a fixed area. At this time, a correlation calculation resource corresponding to the shortage in the share area is allocated to the search window having a shortage of resources. Correlation calculation resources allocated to the search window for the call are released at the timing of call termination. Under the control of the correlation calculation resource control unit 213, this series of correlation calculation resource allocation and release operations is performed. In conjunction with the operation, the correlation calculation resource control unit 213 updates the fixed area management information and the share area management information in the correlation calculation resource setting information storage unit 213a.

  Next, the correlation calculation resource allocation operation of the correlation calculation resource control unit 213 will be described.

  FIG. 6 is a flowchart showing a procedure of correlation calculation resource allocation processing performed by the correlation calculation resource control unit 213.

  The correlation calculation resource control unit 213 first secures A (minimum number) correlation calculation resources (step S10). For example, in the example shown in FIG. 3, the minimum number is two.

  Next, the correlation calculation resource control unit 213 calculates the required resource number B based on the window information 1d from the window allocation unit 24 (step S11). Here, the required resource number B means the number of resources necessary for the correlation calculation based on the search window. The required resource number B may be obtained from the time width information of the search window in the window information 1d. Also, the required number of resources B may be the number of correlation calculation resources necessary for the correlation calculation included in the window information 1d.

  Next, the correlation calculation resource control unit 213 determines whether or not the required resource number B is a minimum number A or less (step S12). When the required resource number B exceeds the minimum number A, the correlation calculation resource control unit 213 determines whether or not the number of usable correlation calculation resources in the share area is greater than or equal to the shortage number (= B−A). Is confirmed (step S13). When the number of usable correlation calculation resources is equal to or greater than the shortage number, the correlation calculation resource control unit 213 has the required number B of correlation calculation resources as correlation calculation resources to be allocated to the search window in the fixed area and the share area. Is secured (step S14).

  If it is determined in step S12 that the required resource number B is the minimum number A or less, in step S14, the correlation calculation resource control unit 213 sets the minimum number of correlation calculation resources to be allocated to the search window in the fixed area. A correlation calculation resource of A is secured.

  Further, in the determination of step S13, if the number of usable correlation calculation resources is less than the shortage number, in step S14, the correlation calculation resource control unit 213 determines the number of correlation calculation resources to be allocated to the search window, The minimum number A is the number obtained by adding the number of available correlation calculation resources in the share area. Then, the correlation calculation resource control unit 213 secures the added number of correlation calculation resources as correlation calculation resources to be allocated to the search window in the fixed area and the share area. When the number of available resources in the share area is 0, the correlation calculation resource control unit 213 secures a minimum number A of correlation calculation resources as correlation calculation resources allocated to the search window in the fixed area. To do.

  After the correlation calculation resource control unit 213 allocates the correlation calculation resource to the search window in step 14, the delay profile generation unit 22 calculates the correlation value using the allocated correlation calculation resource. .

  When all the correlation calculation resources are allocated in the fixed area, for example, in the correlation calculation resource setting information shown in FIG. 3, the correlation calculation resource in the fixed area is assigned to n search windows. In the case of the error, the correlation calculation resource control unit 213 interrupts the allocation of the correlation calculation resource to the delay profile generation unit 22 (transmission of the resource determination information 1e).

  In the receiving apparatus according to the present embodiment described above, the correlation calculation resource control unit 213 dynamically allocates the correlation calculation resource in the delay profile generation unit 22 according to the time width of the search window allocated by the window allocation unit 212. It is characterized by controlling. More specifically, the delay profile generation unit 22 performs control for allocating a predetermined number of correlation calculation resources from the fixed area to the search window allocated by the window allocation unit 212. When the number of correlation calculation resources is insufficient only by the allocation of correlation calculation resources in the fixed area, the delay profile generation unit 22 performs control for allocating the insufficient number of correlation calculation resources from the share area.

  According to the above feature, since the correlation calculation resources are dynamically allocated according to the time width of the search window, the entire apparatus as compared with the one in which the number of correlation calculation resources allocated to the search window is fixed to the maximum number. The number of necessary correlation calculation resources can be reduced.

  Specifically, as shown in FIG. 7, in the case of assigning correlation calculation resources to n search windows, two correlation calculation resources are secured in the fixed area for each search window. Correlation calculation resources that can be used between search windows are secured in the share area. In the example shown in FIG. 3, when six correlation calculation resources are secured for each search window, n × 6 number of correlation calculation resources are required. On the other hand, in the example shown in FIG. 7, n × 2 number of correlation calculation resources in the fixed area and m correlation calculation resources in the share area are required. The number (m) of correlation calculation resources in the share area is smaller than the number (n × 4) obtained by subtracting the number of n × 2 from the number of n × 6. That is, in the present embodiment, it is possible to reduce the correlation calculation resources by the number obtained by subtracting the value of (n × 4) from m, compared to the example shown in FIG.

(Other embodiments)
In the receiving apparatus according to the above-described embodiment, when there are a sufficient number of correlation calculation resources available in the share area, the correlation calculation resources in the share area can be sufficiently used between the calls. However, for a call set after the number of usable correlation calculation resources in the share area is exhausted, no correlation calculation resource is allocated from the share area. In this way, there is an extreme difference in the number of correlation calculation resources that can be used in the share area between calls. Here, an embodiment will be described in which allocation of correlation calculation resources from the share area can be limited when the number of usable correlation calculation resources in the share area falls below a threshold value.

  The receiving apparatus of the present embodiment has basically the same configuration as that of the receiving apparatus shown in FIGS. 1 to 5, but the correlation calculation resource in the delay profile generation unit 22 by the function calculation resource control unit 213. The allocation control is different.

  FIG. 8 is a flowchart showing a procedure of correlation calculation resource allocation processing performed by the correlation calculation resource control unit 213 of the receiving apparatus of this embodiment.

  The correlation calculation resource control unit 213 first secures A (minimum number) correlation calculation resources (step S20). For example, in the example shown in FIG. 3, the minimum number is two.

  Next, the correlation calculation resource control unit 213 calculates the required resource number B based on the window information 1d from the window allocation unit 24 (step S21). Here, the required resource number B means the number of resources necessary for performing a correlation operation based on the search window.

  Next, the correlation calculation resource control unit 213 determines whether or not the required resource number B is a minimum number A or less (step S22). When the required resource number B exceeds the minimum number A, the correlation calculation resource control unit 213 determines whether or not the number of usable correlation calculation resources in the share area is greater than or equal to the shortage number (= B−A). Is confirmed (step S23).

  If it is determined in step S23 that the number of usable correlation calculation resources in the share area is equal to or greater than the shortage number, the correlation calculation resource control unit 213 obtains the number C of usable correlation calculation resources in the share area. (Step S24). Then, the correlation calculation resource control unit 213 determines whether or not the number C of usable correlation calculation resources is smaller than the threshold (step S25). The number C of correlation calculation resources can be obtained by examining the setting information in the correlation calculation resource setting information storage unit 213a.

  If the number C of usable correlation calculation resources is equal to or greater than the threshold value in the determination in step S25, the correlation calculation resource control unit 213 uses the required resources as correlation calculation resources to be allocated to the search window in the fixed area and the share area. The number B of correlation calculation resources is secured (step S27).

  If the number C of usable correlation calculation resources is smaller than the threshold value in the determination in step S25, the correlation calculation resource control unit 213 limits the number of allocations to the search window from the share area to a predetermined number (step S26). In step S27, the correlation calculation resource control unit 213 secures a minimum number A and a predetermined number of correlation calculation resources in the fixed area and the share area as correlation calculation resources to be allocated to the search window. . Here, the predetermined number is a fixed number that is appropriately set under the condition that call disconnection does not occur.

  If it is determined in step S23 that the number of available correlation calculation resources is less than the shortage in step S13, the correlation calculation resource control unit 213 allocates the correlation calculation resource to the search window in step S27. Is the minimum number A plus the number of correlation calculation resources available in the share area. Then, the correlation calculation resource control unit 213 secures the added number of correlation calculation resources as correlation calculation resources to be allocated to the search window in the fixed area and the share area. When the number of available resources in the share area is 0, the correlation calculation resource control unit 213 secures a minimum number A of correlation calculation resources as correlation calculation resources allocated to the search window in the fixed area. To do.

  After the correlation calculation resource control unit 213 allocates the correlation calculation resource to the search window in step 27, the delay profile generation unit 22 calculates the correlation value using the allocated correlation calculation resource. .

  When all the correlation calculation resources are allocated in the fixed area, for example, in the correlation calculation resource setting information shown in FIG. 3, the correlation calculation resource in the fixed area is assigned to n search windows. In the case of the error, the correlation calculation resource control unit 213 interrupts the allocation of the correlation calculation resource to the delay profile generation unit 22 (transmission of the resource determination information 1e).

  Similar to the receiving apparatus shown in FIG. 1, the receiving apparatus of the present embodiment is characterized in that the correlation calculation resource control unit 213 dynamically allocates correlation calculation resources according to the time width of the search window. . With this feature, the number of correlation calculation resources of the delay profile generation unit 22 can be reduced.

  In addition, in the receiving apparatus according to the present embodiment, when the number of correlation calculation resources that can be used in the share area falls below the threshold, the correlation calculation resource control unit 213 assigns the correlation calculation resources to the search window in the share area. It has another feature of restricting. According to this feature, it is possible to suppress an extreme difference in the number of correlation calculation resources that can be used in the share area between calls.

  The receiving apparatus of each embodiment described above is an example of the present invention, and the configuration and operation thereof can be changed as appropriate without departing from the spirit of the invention.

  In any one of a plurality of search windows set for a certain call, the determination result in step S13 in FIG. 6 or step S23 in FIG. 8 indicates that the number of usable correlation calculation resources in the share area is insufficient. If not, the correlation calculation resource assigned to the search window is less than the required number of resources. In this case, the correlation level in the search window is low. As a technique for solving this problem, there are the following first and second resource allocation processes.

  In the first resource allocation process, the number of correlation calculation resources allocated by the correlation calculation resource control unit 213 among the plurality of search windows allocated to the call from the transmission side by the window allocation unit 212 becomes the required number of resources. Discard search windows that do not meet. Specifically, in any of a plurality of search windows set for a certain call, the determination result in step S13 in FIG. 6 or step S23 in FIG. 8 indicates the number of correlation calculation resources that can be used in the share area. Is determined to be less than the shortage number, the window allocating unit 212 discards the information of the low correlation level among the search windows. Thereby, since the correlation calculation resource is not allocated by the correlation calculation resource control unit 213 for the window having a low correlation level, it is possible to suppress a decrease in the accuracy of the correlation calculation.

  In the second resource allocation process, the total number of correlation calculation resources allocated by the correlation calculation resource control unit 213 is required among the plurality of search windows allocated by the window allocation unit 212 to the call from the transmission side. When there are search windows less than the number of resources, the search windows are allocated to the delay profile generation unit 210 in a time division manner. Specifically, in any of a plurality of search windows set for a certain call, the determination result in step S13 in FIG. 6 or step S23 in FIG. 8 indicates the number of correlation calculation resources that can be used in the share area. Is determined to be less than the shortage number, the window allocation unit 212 allocates these search windows to the delay profile generation unit 210 in a time division manner. In this case, correlation calculation resources can be allocated to all search windows.

  In mobile communication, there are a first state in which a plurality of highly correlated delay positions exist, and a second state in which the delay positions fluctuate from moment to moment. Depending on the multipath environment, the first or second state or There are both first and second states. In order to suppress the degradation of reception characteristics, a plurality of search windows having different delay positions are set when the first state exists, and the search window update period is shortened when the second state exists. When the first and second states exist, a countermeasure is taken such that a plurality of search windows having different delay positions are updated in a short cycle. The first resource allocation process is effective as a countermeasure when the first state exists. The second resource allocation process is effective as a countermeasure when the second state exists. The combination of the first and second resource allocation processes is effective in countermeasures when the first and second states exist.

  The above-described receiving apparatus of the present invention and a transmitting apparatus (for example, a mobile terminal) that transmits an information signal including a pilot signal (or spreading code) that is a reference signal to the receiving apparatus by wireless communication. A body communication system can be configured. This mobile communication system is a mobile communication system that employs a method such as CDMA or W-CDMA.

It is a block diagram which shows the structure of the receiver which is one Embodiment of this invention. It is a block diagram which shows the structure of the searcher part of the receiver shown in FIG. It is a schematic diagram which shows an example of the correlation calculation resource setting information stored in a correlation calculation resource setting information storage part. It is a block diagram which shows the specific structure of the correlation calculation resource control part and delay profile production | generation part which comprise the searcher part shown in FIG. It is a sequence diagram which shows operation | movement of the searcher part shown in FIG. It is a flowchart which shows one procedure of the allocation process of the correlation calculation resource performed in the correlation calculation resource control part which comprises the searcher part shown in FIG. It is a schematic diagram which shows the mode of the allocation of the correlation calculation resource in the receiver shown in FIG. It is a flowchart which shows one procedure of the allocation process of the correlation calculation resource performed in the correlation calculation resource control part of the receiver which is other embodiment of this invention. It is a block diagram which shows the structure of a searcher part as related technology. It is a schematic diagram which shows the mode of allocation of the correlation calculation resource in the searcher part shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Reception part 20 Demodulation part 21 Searcher part 22 Finger part 23 Decoder part 210 Delay profile generation part 211 Path detection process part 212 Window allocation part 213 Correlation calculation resource control part

Claims (10)

A receiving unit for receiving an information signal including a first reference signal;
A window allocation unit that allocates at least one search window that defines a time width in which the reception timing of each of the information signals received by the reception unit through multipaths can be detected for each call from the transmission device When,
A plurality of correlation calculation resources, the correlation calculation resources used to correlate the information signal received by the receiving unit and the second reference signal corresponding to the first reference signal A correlation calculation unit allocated from a correlation calculation resource;
A correlation calculation resource control unit that dynamically controls allocation of correlation calculation resources in the correlation calculation unit according to a time width of a search window allocated by the window allocation unit. The correlation calculation unit includes a fixed area including a plurality of first correlation calculation resources, and a share area including a plurality of second correlation calculation resources.
The correlation calculation resource control unit allocates a predetermined number of first correlation calculation resources from the fixed area to the search window set by the window allocation unit, and the first correlation calculation resource in the fixed area The receiving device according to claim 1, wherein when the number of correlation calculation resources is insufficient only by the allocation of correlation calculation resources, the insufficient number of second correlation calculation resources are allocated from the share area. A correlation calculation resource setting information storage unit for storing setting information indicating whether or not the first correlation calculation resource is allocated in the fixed area and setting information indicating whether or not the second correlation calculation resource is allocated in the share area; And further,
The correlation calculation resource control unit refers to setting information of the first and second correlation calculation resources in the correlation calculation resource setting information storage unit, and first and second correlation calculations in the fixed area and the share area The receiving apparatus according to claim 2, wherein resource allocation is controlled and the allocation result is reflected in the correlation calculation resource setting information storage unit.   The correlation calculation resource control unit calculates a required resource number from the time width of the search window for the search window set by the window allocating unit, and calculates the first correlation calculation resource in the fixed area from the required resource number. The receiving apparatus according to claim 2, wherein a number obtained by subtracting the number of allocations is used as a shortage of correlation calculation resources.   The window allocating unit has a total number of first and second correlation calculation resources allocated by the correlation calculation resource control unit among the plurality of search windows allocated to the call from the transmission device, the required resource. The receiving apparatus according to claim 4, wherein search windows that are less than the number are discarded.   The window allocating unit is configured such that a total number of first and second correlation calculation resources allocated by the correlation calculation resource control unit among the plurality of search windows allocated to the call from the transmission device is the required number. The receiving device according to claim 4, wherein when there are search windows less than the number of resources, the plurality of search windows are assigned to the correlation calculation unit in a time division manner.   The correlation calculation resource control unit limits the number of allocations of the second correlation calculation resource from the share area when the number of usable second correlation calculation resources in the share area is less than a threshold value. The receiving device according to any one of claims 2 to 4. A receiving device according to claim 1;
A mobile communication system, comprising: a mobile terminal that transmits an information signal including a reference signal to the receiving device by wireless communication. A correlation calculation resource control method for a receiving apparatus having a plurality of correlation calculation resources,
A first step of allocating, from the plurality of correlation calculation resources, a correlation calculation resource used to correlate a received signal including a first reference signal and a second reference signal corresponding to the first reference signal; ,
A second step of allocating at least one search window for defining a time width in which the reception timing of each of the received signals received through the multipath can be detected in each path;
A correlation calculation resource control method comprising: a third step of dynamically controlling the allocation of correlation calculation resources in the first step according to the time width of the search window allocated in the second step. The plurality of correlation calculation resources include a plurality of first correlation calculation resources provided in a fixed area and a plurality of second correlation calculation resources provided in a share area,
The third step performs control for allocating a predetermined number of first correlation calculation resources from the fixed area to the search window allocated in the first step, and in the fixed area The method includes a step of performing control for allocating the insufficient number of second correlation calculation resources from the share area when the number of correlation calculation resources is insufficient only by the allocation of the first correlation calculation resources. The correlation calculation resource control method described in 1.

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