JP4540434B2 - Path search processing apparatus and processing method - Google Patents

Description

  The present invention relates to a path search processing apparatus and processing method, and more particularly to a path search processing apparatus and processing method used in a CDMA (Code Division Multiple Access) type mobile communication system.

  In a CDMA mobile communication system, a plurality of paths (multipaths) having different propagation times generated in a mobile communication environment can be separated and extracted by creating a delay profile. Further, in this communication system, it is possible to improve reception performance by selecting a path for Rake combining from the multipath and obtaining a diversity effect by Rake combining. Searching for a path for Rake synthesis is called a path search.

The conventional path search processing apparatus and processing method obtains the average power from the created delay profile, removes the correlation value lower than the average power, and reduces the number of search correlation values for performing effective path detection, thereby reducing the processing time. And low power consumption (for example, see Patent Document 1).
JP 2000-134135 A

  However, in the conventional path search processing device, the processing speed is increased by the effective path detection method for one delay profile when the path search is activated. For this reason, in the conventional path search processing apparatus, when a plurality of delay profiles are created and a path search is performed, the processing time increases in proportion to the number of delay profiles to be created.

  In addition, when a conventional path search processing apparatus is provided with a plurality of receiving antennas or establishes a radio link with a plurality of cells, all delay profiles are created, particularly in the first path search process when a radio link is added. There was a problem that the wireless link could not be established due to the delay.

  Such processing delay can be shortened by increasing the number of correlators or increasing the processing speed of a DSP (Digital Signal Processor) or the like. However, when the processing delay is shortened by such a method, there arises a problem that the circuit scale and power consumption are increased.

  The present invention has been made in view of this point, and an object of the present invention is to provide a path search processing device and a processing method capable of quickly establishing a radio link without increasing the circuit scale and power consumption.

  In order to solve such a problem, the path search processing device of the present invention detects a valid path from each delay profile by means of delay profile creation means for despreading a received signal using a correlator to create a plurality of delay profiles. A path detecting unit and a finger allocating unit that allocates an effective path to a finger are provided, and when performing a path search for a target cell, only one delay profile is created for the first time of path search activation and a path search is performed.

  According to this configuration, when path search is performed, only one delay profile is created and path search is performed only when the first path search is started. As a result, in this configuration, a wireless link can be quickly established without increasing the circuit scale or power consumption.

  According to the present invention, when a path search is performed on a target cell, only one delay profile is created and the path search is performed only for the first time when the path search is started, so that a radio link is quickly established without increasing the circuit scale or power consumption. be able to.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a path search processing apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, the path search processing apparatus 100 according to the first embodiment includes a delay profile creation unit 101, a path detection unit 102, and a finger assignment unit 103.

  In FIG. 1, a delay profile creation unit 101 creates a delay profile by performing despreading processing on a received signal using a spreading code used in spread modulation on the transmission side using a correlator.

  The path detection unit 102 detects path candidates (hereinafter referred to as “effective paths”) to be used at the time of Rake synthesis from one or a plurality of delay profiles created by the delay profile creation unit 101.

  The finger assigning unit 103 selects a Rake composite path from the effective paths detected by the path detecting unit 102 and assigns it to the finger.

  A baseband received signal is input to the path search processing device 100 through an input unit including a reception antenna 104 and a radio reception unit 105.

  The path search processing apparatus 100 according to the first embodiment receives signals using a plurality of reception antennas (two reception antennas 104a and 104b in this example).

  The wireless reception unit 105 includes a wireless reception unit 105a corresponding to the reception antenna 104a and a wireless reception unit 105b corresponding to the reception antenna 104b.

  Each of the radio reception units 105a and 105b includes a low noise amplifier, a frequency converter to an intermediate frequency, an AGC (Automatic Gain Control), and an AD converter.

  The reception signals received by the reception antennas 104a and 104b are converted into signals in a form that is input to the path search processing device 100 by the radio reception units 105a and 105b (hereinafter referred to as “baseband reception signals”). Is input to the path search processing device 100.

  The output of the path search processing apparatus 100 is given to a demodulator 106 having fingers. The demodulating unit 106 performs Rake combining using the information on the finger assignment path assigned to the finger by the path search processing device 100 and compensation of phase fluctuations for the received signal, and SIR (Signal to interference power ratio). (Interference signal power ratio) measurement and transmission power control.

  Next, the operation of the path search processing apparatus 100 according to the first embodiment will be described using FIG. 2 and FIG. FIG. 2 is a schematic diagram of a radio communication system that performs radio communication between a mobile station apparatus and a base station apparatus using the path search processing apparatus according to the first embodiment. FIG. 3 is a flowchart showing the operation of the path search processing apparatus according to the first embodiment.

  A mobile station apparatus 201 in the radio communication system shown in FIG. 2 includes the receiving antennas 104a and 104b, radio receiving sections 105a and 105b, a path search processing apparatus 100, and a demodulation section 106 shown in FIG. Wireless communication is performed with the base station apparatus 202 which is the destination. Here, the initial path search activation timing of the path search processing apparatus 100 is t = ta.

  In FIG. 3, when the wireless communication of the mobile station apparatus 201 starts, it is first determined whether or not the current time (current time) t is the path search activation timing (step ST201). Here, the path search activation timing ta is to be periodically activated at the activation interval T, and the time t = ta + T, ta + 2T, ta + 3T,... Is the path search activation timing.

  If it is determined in step ST201 that the current time t is the path search activation timing, the path search activation frequency X is counted (step ST202). On the other hand, if it is determined in step ST201 that the current time t is not the path search activation timing, the process does not proceed to steps after step ST202 until the current time t becomes the path search activation timing again.

  At the first path search activation timing, the path search activation frequency X is set to X = 1, and at the subsequent path search activation timing, the path search activation frequency X is incremented by “1”.

  Next, among the plurality of reception antennas 104a and 104b numbered in advance, reception antennas that receive reception signals used to create a delay profile are selected in order from the smallest number (step ST203). Here, it is assumed that the receiving antenna 104a and the receiving antenna 104b are selected in this order.

  Next, the delay profile creating unit 101 creates a delay profile for the baseband received signal received by the receiving antenna 104a selected in step ST203 and generated by the radio receiving unit 105a (step ST204).

  Next, it is determined whether or not the path search activation count X is the first time (step ST205). If it is determined in step ST205 that the path search activation count X is the first (X = 1), the process proceeds to step ST206, and one delay created by the delay profile creation unit 101 in the path detection unit 102. Detect a valid path from the profile.

  Thereafter, the process proceeds to step ST207, where a Rake combined path is selected from the effective paths detected by the path detecting unit 102, and the finger allocating unit 103 allocates the Rake combined path to the fingers of the demodulating unit 106.

  On the other hand, if it is determined in step ST205 that the path search activation count X is not the first (X = 1) but the second or later, the reception antenna 104b that is the next antenna number is selected (step ST208). Then, a delay profile is created for the antenna number selected in step ST208 (step ST209). That is, in this case, the processes of step ST208 and step ST209 are repeated for the number of receiving antennas.

  Thereafter, the process proceeds to step ST206, and in the same manner as in the former case, the path detection unit 102 detects an effective path from one delay profile created by the delay profile creation unit 101. In step ST207, a Rake combined path is selected from the effective paths detected by the path detecting unit 102, and the finger allocating unit 103 allocates the Rake combined path to the fingers of the demodulating unit 106.

  FIG. 4 is a diagram showing the processing steps in the flowchart shown in FIG. 3 in time series. The number of each process shown in FIG. 4 is the same as the number of each step in the flowchart shown in FIG.

  As shown in FIG. 4, at the first path search activation timing t = ta, a delay profile is created in step ST204 for the signal received by the receiving antenna 104a, an effective path is detected in step ST206, and in step ST207. Perform finger assignment.

  In subsequent path search activation timings t = ta + T, t = ta + 2T,..., Delay profiles are created in steps ST204 and ST209 for the signals received by the receiving antennas 104a and 104b, respectively. In ST206, effective paths are detected from all delay profiles, and in step ST207, finger assignment is performed.

  As described above, in the path search processing apparatus 100 according to the first embodiment, the delay profile creation unit 101 uses the correlator to reverse the received signal with the spread code used in the spread modulation on the transmission side. A delay profile is created by performing diffusion processing.

  In the path search processing apparatus 100 of this example, when adding the target cell to the radio link, the delay profile creating unit 101 creates a delay profile for one receiving antenna only when starting the first path search and performs a path search. Therefore, the radio link can be established quickly without increasing the circuit scale and power consumption.

(Embodiment 2)
FIG. 5 is a block diagram showing a configuration of a path search processing apparatus according to Embodiment 2 of the present invention. As shown in FIG. 5, the path search processing apparatus 500 according to the second embodiment generates the baseband reception signal using one reception antenna 104 and one radio reception unit 105, and delay profiles of a plurality of cells. And the cell monitoring unit 501 are different from the path search processing device 100 according to the first embodiment.

  The path search processing device 500 according to the second embodiment has basically the same configuration as the path search processing device 100 according to the first embodiment, and the same reference is given to the same components and functions. Reference numerals are assigned and detailed description thereof is omitted.

  As shown in FIG. 5, the path search processing apparatus 500 according to the second embodiment includes a delay profile creation unit 101, a path detection unit 102, and a finger assignment unit 103.

  The baseband received signal is input to the path search processing device 500 from the received signal input unit including the receiving antenna 104 and the radio receiving unit 105.

  Further, the path search processing device 500 is configured such that the cell monitoring unit 501 monitors cells that become new radio link candidates and manages the cells that become new radio link candidates in descending order of reception level. .

  Next, the operation of the path search processing apparatus 500 according to the second embodiment will be described with reference to FIGS. FIG. 6 is a schematic diagram of a radio communication system in which radio communication is performed between a mobile station apparatus using the path search processing apparatus according to the second embodiment and a plurality of base station apparatuses. FIG. 7 is a flowchart showing the operation of the path search processing apparatus according to the second embodiment.

  A mobile station apparatus 601 in the wireless communication system shown in FIG. 6 includes the reception antenna 104, the wireless reception unit 105, the path search processing device 500, and the demodulation unit 106 shown in FIG. Wireless communication is performed with the station apparatuses 602, 603, and 604. As described above, this radio communication system has the three base station devices 602, 603, and 604 as radio link destinations of the mobile station device 601. Here, the first path search activation timing of the path search processing apparatus 500 is t = ta.

  In FIG. 7, when the wireless communication of the mobile station device 601 starts, first, it is determined whether or not the current time (current time) t is the path search activation timing (step ST701). Here, the path search activation timing ta is to be periodically activated at the activation interval T, and the time t = ta + T, ta + 2T, ta + 3T,... Is the path search activation timing.

  If it is determined in step ST701 that the current time t is the path search activation timing, the path search activation frequency X is counted (step ST702). On the other hand, if it is determined in step ST701 that the current time t is not the path search activation timing, the process does not proceed to steps subsequent to step ST702 until the current time t becomes the path search activation timing again.

  At the first path search activation timing, the path search activation frequency X is set to X = 1, and at the subsequent path search activation timing, the path search activation frequency X is incremented by “1”.

  Next, in step ST703, the cell of the base station apparatus which is the existing radio link destination is used for the baseband received signal received by the receiving antenna 104 and generated by the radio receiving unit 105 using the delay profile creating unit 101. Create a delay profile only. Here, only the delay profile for the cell of base station apparatus 602 is created (step ST703).

  Next, cell monitoring section 501 sequentially selects the cell with the highest reception level from the cells of base station apparatuses 603 and 604 that are candidates for the new radio link (step ST704). Here, the reception level increases in the order of the cell of the base station apparatus 602 that is the current radio link destination, the cell of the base station apparatus 603 that is a candidate for a new radio link, and the cell of the base station apparatus 604 that is a candidate for a new radio link. Shall.

  Next, in step ST705, a delay profile creating unit 101 is used for the baseband received signal received by the receiving antenna 104 and generated by the radio receiving unit 105, and the reception level is selected among the candidates for the new radio link. A base station apparatus cell delay profile that is the maximum is created.

  Next, in step ST706, it is determined whether or not the path search activation count X is the first time (X = 1). If it is determined in step ST706 that the path search activation count X is the first (X = 1), the process proceeds to step ST707, where the path detection unit 102 uses the existing wireless profile created by the delay profile creation unit 101. The effective path is detected only from the delay profile of the cell of the base station apparatus 602 that is a link and the delay profile of each cell of the base station apparatus 603 that is a candidate for a new radio link.

  Thereafter, the process proceeds to step ST708, where a Rake composite path is selected from the effective paths detected by the finger assigning unit 103, and a Rake composite path is assigned to the fingers of the demodulating unit 106.

  On the other hand, when it is determined in step ST706 that the path search activation count X is not the first time (X = 1) but the second or later time, in step ST709, the next additional link destination that is a candidate for a new wireless link. Is designated (step ST709), and delay profile creation for the number of cells of the designated link destination is repeated (step ST710). Here, since the cell of the base station apparatus 603 becomes the radio link destination at the previous path search activation timing, the processing for the cell of the base station apparatus 604 that is a candidate for a new radio link other than the cell of the base station apparatus 603 is performed. Done.

  Thereafter, the process proceeds to step ST707, where the path detection unit 102 uses the delay profile creation unit 101 to create the cell delay profile of the base station device 602, which is an existing radio link, and the base station device 603, which is a candidate for a new radio link. The effective path is detected only from the delay profile of each cell 604.

  Then, the process proceeds to step ST708, where a Rake composite path is selected from the effective paths detected by the finger assigning unit 103, and a Rake composite path is assigned to the fingers of the demodulating unit 106.

  FIG. 8 is a diagram showing the processing steps in the flowchart shown in FIG. 7 in time series. The number of each process shown in FIG. 8 is the same as the number of each step in the flowchart shown in FIG.

  As shown in FIG. 8, at the first path search activation timing t = ta, the cell of the base station apparatus 602 that is an existing radio link and the base station apparatus 603 having the maximum reception level among the candidates for the new radio link. Only a cell creates a delay profile in steps ST703 and ST705, detects a valid path in step ST707, and assigns a finger in step ST708.

  Further, at subsequent path search activation timings t = ta + T, ta + 2T..., The cell of the base station apparatus 602 and the cell of the base station apparatus 603 and the cell of the base station apparatus 604 that is another candidate for a new radio link are included. In contrast, a delay profile is created in step ST710, valid paths are detected from all delay profiles in step ST707, and finger assignment is performed in step ST708.

  As described above, in the path search processing apparatus 500 according to the second embodiment, the delay profile creation unit 101 uses the correlator to reverse the received signal with the spread code used in the spread modulation on the transmission side. A delay profile is created by performing diffusion processing.

  Then, in the path search processing device 500 of this example, when adding a plurality of cells to the radio link, only one cell having the maximum reception level is created and the path search is performed only when the first path search is started. A wireless link can be quickly established without increasing the circuit scale and power consumption.

  Further, in the path search processing apparatus 500 of this example, only when the first path search is started, the path search is performed for one cell among the existing radio link and the new radio link candidate, so that the handover state can be quickly established. It is possible to secure reception quality earlier.

  In addition, in the path search processing device 100 according to the first embodiment and the path search processing device 500 according to the second embodiment, when adding the target cell to the radio link, a plurality of reception antennas or a plurality of new radio link candidates In the above example, only one delay profile is created and the path search is performed only when the first path search is started, but when the target cell to be added to the radio link is applied with Beam forming, the delay profile creating means When creating a delay profile using a normal channel and a delay profile using a beam-formed channel, only one of the normal channel and the beam-formed channel is used only when the first path search is started. Create one delay profile It is also feasible in the same manner to Susachi, it is possible to obtain the same effect.

  Further, in the path search processing device 100 according to the first embodiment and the path search processing device 500 according to the second embodiment, the example in which the path search activation timing is periodically generated has been described. The same can be done when the start timing occurs.

  Further, in the path search processing device 100 according to the first embodiment and the path search processing device 500 according to the second embodiment, the case where the target cell is added to the radio link has been described. When the information is updated and the path search is required again, the path search activation count X is cleared, and the path search activation count X = 1 is incremented again at each path search activation timing. Similar effects can be obtained.

  In the path search processing apparatus 100 according to the first embodiment, an example has been described in which numbering is performed on a plurality of receiving antennas, a receiving antenna is selected in ascending order of numbers, a delay profile is created, and a path search is performed. The same can be applied to the case where a receiving antenna is arbitrarily selected one by one from a plurality of receiving antennas.

  Since the path search processing device according to the present invention can quickly establish a radio link without increasing the circuit scale or power consumption, the path search processing used in a CDMA (Code Division Multiple Access) type mobile communication system Useful as a device.

1 is a block diagram showing a configuration of a path search processing apparatus according to Embodiment 1 of the present invention. Schematic diagram of a radio communication system that performs radio communication between a mobile station apparatus and a base station apparatus using the path search processing apparatus according to Embodiment 1 of the present invention. The flowchart which shows operation | movement of the path search processing apparatus which concerns on Embodiment 1 of this invention. The figure which showed the process in the flowchart shown in FIG. 3 in time series The block diagram which shows the structure of the path search processing apparatus which concerns on Embodiment 2 of this invention. Schematic diagram of a radio communication system that performs radio communication between a mobile station apparatus using a path search processing apparatus according to Embodiment 2 of the present invention and a plurality of base station apparatuses The flowchart which shows operation | movement of the path search processing apparatus which concerns on Embodiment 2 of this invention. The figure which represented the process in the flowchart shown in FIG. 7 in time series

Explanation of symbols

100, 500 Path search processing device 101 Delay profile creation unit 102 Path detection unit 103 Finger assignment unit 104, 104a, 104b Reception antenna 105, 105a, 105b Radio reception unit 106 Demodulation unit 501 Cell monitoring unit 201, 601 Mobile station device 202, 602, 603, 604 Base station apparatus

Claims (5)

A delay profile creating means for despreading a received signal using a correlator to create a plurality of delay profiles;
Path detection means for detecting a valid path from each delay profile;
Finger assigning means for assigning effective paths to the fingers,
A path search processing apparatus characterized in that, when performing a path search for a base station apparatus at a radio link destination, only one delay profile is created and the path search is performed only for the first time of path search activation. A plurality of receiving antennas ;
2. The path search processing apparatus according to claim 1, wherein only one of the plurality of reception antennas is used to create the delay profile and perform a path search only for the first time when the path search is activated. When a plurality of base station devices other than the base station device that is an existing wireless link destination is a new wireless link destination candidate, only the first time of path search activation, the base station device of the existing wireless link destination, path search processing apparatus according to claim 1, characterized in that the path search to create the delay profiles for the largest one base station apparatus the reception level from among a plurality of base station apparatuses. A path search processing device according to any one of claims 1 to 3 is provided, and a call function and a data transmission / reception function are realized based on a received signal demodulated using the path search processing device. A wireless receiver. A delay profile creation step of creating a plurality of delay profiles by despreading the received signal using a correlator;
A path detection step for detecting a valid path from each delay profile;
A finger assignment step for assigning the effective path to the fingers,
A path search processing method characterized in that when performing a path search for a base station apparatus at a radio link destination, a single delay profile is created and the path search is performed only for the first time when the path search is started.

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