JP2004356840A - Cdma receiver and its path capturing device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a path position at a high speed with high accuracy. <P>SOLUTION: A path timing detecting section 12 detects path timing from a baseband spread signal from a wireless receiving section 11 and delivers it as path information (delay profile) to a data base section 15. The data base section prestores advance information (peripheral information), stores path information, outputs path timing information indicative of path position estimation results for a current receiving signal, and outputs it as a despread timing signal through the path timing detecting section. A despread section 13 receives the baseband spread signal and the despread timing signal, delivers the despread baseband signal to a data demodulating section 14 and outputs demodulated data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a CDMA receiving apparatus and a path capturing apparatus and method thereof, and more particularly to a CDMA wireless signal receiving apparatus of a CDMA wireless communication system and a path position detected from a received baseband spread signal used for the CDMA wireless signal receiving apparatus. The present invention relates to a path capturing device that determines a despread timing of a spread signal and a path capturing method.
[0002]
[Prior art]
A conventional CDMA receiving apparatus includes a radio receiving unit that converts a carrier signal transmitted from a transmitting side and received through an antenna into a baseband spread signal, and a path timing (path position, despreading) for performing despreading from the baseband spread signal. Timing), a despreading unit for despreading the baseband spread signal in accordance with the despreading timing, and a demodulation process on the despread baseband spread signal, that is, a normal baseband signal, and transmitted. And a data demodulation unit for restoring the decoded data (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2000-269854 (page 2, FIG. 1-2)
[0004]
[Problems to be solved by the invention]
In the above-described conventional CDMA receiver, when the path timing is detected by the path timing detection unit, only the current reception signal is used, and the path position is detected within a prescribed time of one slot (or several slots). Therefore, it may take time to detect the path position, and as a result, the reception accuracy may be deteriorated.
[0005]
An object of the present invention is to provide a CDMA receiving apparatus capable of following a rapid change in path timing and improving reception accuracy by detecting a path position at high speed and with high accuracy, and a path capturing apparatus and method thereof. Is to do.
[0006]
[Means for Solving the Problems]
A path acquisition device according to claim 1 of the present invention is used for a CDMA wireless signal receiving device of a CDMA wireless communication system, detects a path position from a received baseband spread signal, and despreads the received baseband spread signal. In a path capture device that determines the path information, a database that records peripheral information known in advance and past path transitions, and estimates path transitions for new received signals at high speed and with high accuracy based on these recorded information. Having means.
[0007]
A path acquisition device according to a second aspect of the present invention is the path acquisition device according to the first aspect, wherein a received baseband spread signal and a spread signal generated from a known pilot code and a spread code included in the received signal are input. A correlation value calculating means for calculating a cross-correlation relationship between these two signals while shifting the phase and outputting the correlation signal data; and inputting correlation value data from the correlation value calculating means, and outputting correlation power value data. Correlation power value calculation means, correlation power value data from the correlation power value calculation means, integration calculation means for outputting correlation power integration data, and correlation power integration data from the integration calculation means, A delay profile detecting means for selecting a predetermined number of upper timings of the correlation power integrated data and outputting the selected timing as a delay profile which is path information; A second database means for storing the delay profile from the delay profile detecting means, and a current path based on past path change information obtained from the stored delay profile and peripheral information obtained from the second database means. A first database means for outputting path timing information estimated to move the data, a delay profile from the delay profile detecting means, and path timing information from the first database means, and a despread timing signal. Output path timing adjusting means.
[0008]
A CDMA receiving apparatus according to claim 3 of the present invention is a CDMA wireless signal receiving apparatus of a CDMA wireless communication system, wherein the wireless receiving means receives a CDMA wireless signal through an antenna and outputs a baseband spread signal; The path capture device according to claim 1 or 2, wherein a baseband spread signal from the means is input, a path position is detected, a despread timing of the received baseband spread signal is determined and output as a despread timing signal. Despreading means for receiving a baseband spread signal from a radio receiving means and a despreading timing signal from the capturing device and outputting a baseband signal whose spread has been despread, and a baseband signal from the despreading means. Data demodulating means for inputting a signal and outputting demodulated data.
[0009]
A CDMA receiving apparatus according to a fourth aspect of the present invention is the CDMA receiving apparatus according to the third aspect, wherein the CDMA receiving apparatus is used for a base station of a CDMA wireless communication system and has a limited mobility of a mobile station within a wireless area of its own base station. Peripheral information that makes it possible to infer the transition status of the path position based on the range is recorded in the database unit of the acquisition device, and the transition information of the path position accompanying the movement of the mobile station is recorded in the database unit of the acquisition device. Having a configuration.
[0010]
The path acquisition method according to claim 5 of the present invention is used in a CDMA wireless signal receiving apparatus of a CDMA wireless communication system, detects a path position from a received baseband spread signal, and performs despreading timing of the received baseband spread signal. In the path capturing method in the path capturing device for determining the path information, the peripheral information known in advance and the past path transition are recorded in the database means, and the path transition for a new received signal is performed at high speed based on the recorded information. And a step of estimating with high accuracy.
[0011]
A path acquisition method according to claim 6 of the present invention is the path acquisition method according to claim 5, wherein the peripheral information is registered in advance in the second database means, and the received baseband spread signal and A cross-correlation between two signals with a spread signal generated from a known pilot code and a spread code included in the signal is calculated while shifting the phase to obtain correlation value data, and correlation power value calculation means calculates a correlation value from the correlation value data. The power value data is calculated, the integration calculation means calculates the correlation power integration data from the correlation power value data, and the delay profile detection means selects a predetermined number of upper timings of the correlation power integration data to be path information. A delay profile is calculated, the first database means stores the delay profile from the delay profile detecting means, and the stored delay profile is stored. From the past path transition information obtained from the file and the peripheral information obtained from the second database means, the current path movement is estimated and output as path timing information. The path timing adjustment means detects the delay profile. Determining the despread timing from the delay profile from the means and the path timing information from the first database means and outputting the same as a despread timing signal.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
First, the outline of the present invention will be described. The CDMA receiving apparatus according to the present invention is mainly used for a base station (or a mobile station) of a mobile communication system of a CDMA radio access system, and the peripheral information of the own base station and the movement of the partner mobile station which are known in advance. By recording the past path transition in the received signal of the own base station in the database, the path transition for the new received signal can be estimated, and the path position can be determined with higher accuracy. That is, a database is added to the path capturing device in the conventional CDMA receiving device, peripheral information for estimating a path transition is input in advance, and a change in the past path movement is recorded. Is used to determine the current path position.
[0013]
The peripheral information is obtained by quantifying road information around the base station, arrangement of buildings, and the like. Mobile stations (people, cars, trains, etc.) often move at a substantially fixed speed around a substantially fixed place (on a road or railroad) around a base station. Therefore, stations that move outside of these limits are handled by the conventional path acquisition processing, and stations that move along the assumed route are detected at high speed and with high accuracy using a database. By performing (capturing) and feeding back the path detection result to the database, fluctuations from the peripheral information are absorbed.
[0014]
Thus, the present invention can determine a path position faster and more accurately than a conventional CDMA receiver (path acquisition device).
[0015]
Next, embodiments of the present invention will be described in detail with reference to the drawings.
[0016]
FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, the CDMA receiving apparatus of the present example has a radio receiving unit 11 that receives a carrier signal received from an antenna and outputs a baseband spread signal, and receives a baseband spread signal from the wireless receiving unit 11 and sets a path timing. A path timing detection unit 12 that detects and outputs the same to the database unit 15 as path information, determines a despread timing based on the path timing information indicating the path position estimation result from the database unit 15, and outputs it as a despread timing signal; A despreading unit 13 that receives a baseband spread signal from the radio reception unit 11 and a despread timing signal from the path timing detection unit 12 and outputs a baseband signal whose spread is despread, A data demodulation unit 14 for inputting a baseband signal and outputting demodulated data; A database unit 15 for storing path information from the detection unit 12 and prior information (peripheral information) from information input means (not shown) and outputting path timing information indicating a result of estimating a path position with respect to a currently received signal; It has. Note that, of the CDMA receiving device, a portion of the path timing detecting unit 12 and the database unit 15 is particularly called a path capturing device.
[0017]
FIG. 2 is a diagram showing a detailed configuration example of this path capturing device, that is, the path timing detecting unit 12 and the database unit 15 shown in FIG.
[0018]
In FIG. 2, path timing detecting section 12 includes a spread signal generated by a pilot code and a spreading code that are known to be included in the received signal in advance, a baseband spread signal output from radio receiving section 11, And a correlation value calculator 121 that calculates the cross-correlation between these two signals while shifting the phase (timing) of the two signals and outputs the correlation value data, and correlation value data from the correlation value calculator 121. , And outputs a correlation power value data, a correlation power value data from the correlation power value calculation unit 122 as an input, an integration calculation unit 123 that outputs correlation power integration data, and an integration calculation unit 123 The correlation power integrated data from the input is input, and a predetermined number of upper timings of the correlation power integrated data are selected as a delay profile which is path information. Delay profile detector 124, correlation power value data from correlation power calculator 122, correlation power integrated data from integral calculator 123 through delay profile detector 124, delay profile from delay profile detector 124 , And a path timing adjustment unit 125 that receives path timing information from the database unit 15 and outputs a despread timing signal.
[0019]
In FIG. 2, a database unit 15 inputs and stores a peripheral information database 152 in which peripheral information prepared and input in advance and a delay profile from the delay profile detection unit 124 are input, and a past profile obtained from the stored delay profile is input. The main database 151 is configured to output path timing information that estimates the current path movement from path transition information and peripheral information obtained from the peripheral information database 152. Note that the main database 151 and the peripheral information database 152 have data storage means for storing data, and the main database 151 controls data storage and reference to the data storage means, and data for estimating path movement. It has control means.
[0020]
Next, the overall operation of this embodiment will be described in detail with reference to FIGS.
[0021]
In the CDMA system, it is assumed that a radio signal is temporally divided into frames, and one frame is divided into several slots. A CDMA transmitting apparatus, which is a transmission source, generates an encoded baseband signal together with a pilot signal from transmission data, spreads the baseband signal with a spreading code to generate a baseband spread signal, modulates the carrier frequency signal, and transmits the signal from an antenna.
[0022]
Referring to FIG. 1, a signal of a carrier frequency transmitted from a partner CDMA transmitting apparatus (transmission source) and received by an antenna is converted into a baseband spread signal by a radio reception unit 11.
[0023]
The path timing detection unit 12 obtains the despread timing from the baseband spread signal in cooperation with the database unit 15 and notifies the despread unit 13 as a despread timing signal.
[0024]
The despreading unit 13 despreads the baseband spread signal at the notified despread timing.
[0025]
The data demodulation unit 14 demodulates the baseband signal despread by the despreading unit 13 to obtain demodulated data.
[0026]
Next, the operations of the path timing detection unit 12 and the database unit 15, which are path acquisition devices, will be described with reference to FIG.
[0027]
The baseband spread signal output from the radio reception unit 11 is input to the correlation value calculation unit 121 of the path timing detection unit 12, where a known signal sequence (“pilot code”, “pilot code”, “ A correlation with a code obtained by spreading a “PL code” with a spreading code is calculated. This correlation value has a large value at a point synchronized with the PL code. The known PL code is usually stored and held in the device. The correlation value data obtained by the correlation value calculator 121 is input to the correlation power value calculator 122.
[0028]
The correlation power value calculation unit 122 calculates the correlation power value data of the slot using the correlation value data. The correlation power value data obtained by the correlation power value calculation unit 122 is input to the integration calculation unit 123.
[0029]
The integration calculation unit 123 integrates the correlation power value data of each slot, integrates a predetermined number of slots, and then activates the delay profile detection unit 124. By performing the integration process, the data is averaged to reduce the influence of noise and the like.
[0030]
The delay profile detection unit 124 sets the point at which the value of the correlation power integrated data becomes maximum as the delay profile. This is because the correlation value has a large value at the point where the PL code is synchronized. Further, the correlation power integrated data and the obtained delay profile are stored and held until the next delay profile detection process is started so that the delay timing detection processing can be started so that the path power adjustment unit 125 and the database unit 15 (main database 151) can refer to the data.
[0031]
The database unit 15 includes the delay profile from the delay profile detection unit 24, the past path position change information stored in the main database 151, and the previously input peripheral information stored in the peripheral information database 152. , And the current path position is estimated, and the path timing information is output to the path timing adjustment unit 125.
[0032]
When this CDMA receiver is used for a base station (fixed position), the source of the radio signal is the mobile station (plural stations). Since a plurality of transmission sources (mobile stations) moving within the radio area of the base station often move on a predetermined route such as a road, a plurality of transmission sources (base stations) are provided for each transmission source on the CDMA receiving apparatus (base station) side. It is possible to estimate the current path position from the transition of the past path position due to the transmission source of (1). Further, since information on the surroundings is input in advance, it is possible to estimate the path position based on the information until the learning function of the database operates efficiently.
[0033]
When this CDMA receiving apparatus is used for a mobile station, the source of the radio signal is a base station (position fixed). Even in this case, if the CDMA receiving apparatus (mobile station) frequently moves on a predetermined route such as a road, the CDMA receiving apparatus (mobile station) determines the current path position from the past path position change. It is possible to estimate. Further, since information on the surroundings is input in advance, it is possible to estimate the path position based on the information until the learning function of the database operates efficiently.
[0034]
The path timing adjustment unit 125 is activated for each slot, and based on the correlation power value data of the slot, the correlation power integration data, the delay profile from the delay profile detection unit 124, and the path timing information from the database unit 15, the path timing adjustment unit 125 Find the despread timing.
[0035]
As described above, since the adjustment is performed for each slot using the information of the path position estimated in advance, the path position can be accurately determined at high speed, and it is possible to follow a rapid change in the despreading timing. .
[0036]
【The invention's effect】
According to the present invention, the current path position is estimated by using the accumulated transition information of the past path position, and the path position in each slot is detected at high speed and with high accuracy, as well as information on the surrounding area is determined in advance. Input, and the range in which the communication partner moves can be fixed, enabling high-speed and high-precision detection of path timing even before past path transition information is accumulated. It is possible to follow, and it is possible to improve reception accuracy.
[Brief description of the drawings]
FIG. 1 is a block diagram of a CDMA receiving apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a detailed configuration example of a path timing detection unit and a database unit illustrated in FIG. 1;
[Explanation of symbols]
Reference Signs List 11 radio receiving unit 12 path timing detecting unit 13 despreading unit 14 data demodulating unit 15 database unit 121 correlation value calculating unit 122 correlation power value calculating unit 123 integration calculating unit 124 delay profile detecting unit 125 path timing adjusting unit 151 around main database 152 Information database

Claims (6)

A path acquisition device that is used in a CDMA wireless signal receiving device of a CDMA wireless communication system, detects a path position from a received baseband spread signal, and determines a despread timing of the received baseband spread signal.
It is characterized by having database means for recording peripheral information known in advance and past path transitions, and for quickly and accurately estimating path transitions for new received signals based on these recorded information. Path capture device. A received baseband spread signal and a spread signal generated from a known pilot code and a spread code included in the received signal are input, the cross-correlation between these two signals is calculated while shifting the phase, and output as correlation value data. Correlation value calculating means,
Correlation power value calculation means for inputting correlation value data from the correlation value calculation means and outputting correlation power value data,
Integration calculation means for inputting correlation power value data from the correlation power value calculation means and outputting correlation power integration data,
Delay profile detection means for inputting the correlation power integration data from the integration calculation means, selecting a predetermined number of upper timings of the correlation power integration data, and outputting the selected timing as a delay profile which is path information;
A second database means in which peripheral information is registered in advance;
Path timing information which accumulates the delay profile from the delay profile detecting means and estimates the current path movement from past path transition information obtained from the accumulated delay profile and peripheral information obtained from the second database means. First database means for outputting
2. The apparatus according to claim 1, further comprising a path timing adjusting unit that inputs a delay profile from the delay profile detecting unit and path timing information from the first database unit and outputs a despread timing signal. Path capture device. In a CDMA wireless signal receiving apparatus of a CDMA wireless communication system,
Wireless receiving means for receiving a CDMA wireless signal through an antenna and outputting a baseband spread signal;
3. The path capture device according to claim 1, wherein a baseband spread signal from the radio receiving unit is input, a path position is detected, a despread timing of the received baseband spread signal is determined, and the despread timing signal is output. When,
Despreading means for inputting a baseband spread signal from the wireless receiving means and a despreading timing signal from the capturing device and outputting a baseband signal whose spread has been despread,
A CDMA receiving apparatus comprising: a data demodulating unit that inputs a baseband signal from the despreading unit and outputs demodulated data. Peripheral information used for a base station of a CDMA wireless communication system and capable of estimating a path position change state based on a limited movable range of a mobile station within a wireless area of the base station is stored in database means of the capturing device. 4. The CDMA receiving apparatus according to claim 3, wherein the CDMA receiving apparatus records the path position change information accompanying the movement of the mobile station in a database means of the capturing apparatus. A path acquisition method in a path acquisition device that is used in a CDMA wireless signal receiving device of a CDMA wireless communication system, detects a path position from a received baseband spread signal, and determines a despread timing of the received baseband spread signal,
A path characterized by recording peripheral information known in advance and past path transitions in a database means, and estimating a path transition for a new received signal at high speed and with high accuracy based on these recorded information. Capture method. The peripheral information is registered in advance in the second database means,
Correlation value calculation means calculates the cross-correlation between two signals of the received baseband spread signal and a spread signal generated from a known pilot code and a spread code included in the received signal while shifting the phase to obtain correlation value data. ,
Correlation power value calculation means calculates correlation power value data from the correlation value data,
Integral calculation means calculates correlation power integration data from the correlation power value data,
The delay profile detecting means selects a predetermined number of upper timings of the correlation power integrated data, calculates a delay profile that is path information,
The first database means accumulates the delay profile from the delay profile detecting means, and determines the current path from past path transition information obtained from the accumulated delay profile and peripheral information obtained from the second database means. Guess movement and output as path timing information,
The path timing adjusting means determines a despread timing from a delay profile from the delay profile detecting means and path timing information from the first database means, and outputs it as a despread timing signal. 6. The path capturing method according to 5.

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