JP2002217779A - Method and system for assigning rake reception finger at reception of polarized wave diversity in cdma communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a finger assignment method for RAKE reception that can efficiently detect a path of both antenna branches at reception of polarized wave diversity so as to assign a finger to a detected path. SOLUTION: In the RAKE reception finger assignment method by which a RAKE finger is assigned to a reception path of a prescribed signal when a 1st polarized wave antenna branch and a 2nd polarized wave antenna branch whose polarized planes are different receive the prescribed signal subjected to spread modulation coming from a transmitter side in terms of the polarized wave diversity in the CDMA communication simultaneously conducting a plurality of communications through the use of signals in the same frequency band, the task above can be solved by the RAKE finger assignment method where the 1st polarized wave antenna branch detects the reception path, the 2nd polarized wave antenna branch detects a path on the basis of the detected path and the finger for RAKE reception is assigned to the detected path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a RAKE receiving method in a mobile communication system, and more particularly, to a RAKE receiving method when polarization diversity is applied to a base station used in a CDMA cellular mobile communication system. It relates to a finger assignment method.

[0002] The present invention also relates to a base station capable of performing finger assignment according to such a finger assignment method.

[0003]

2. Description of the Related Art Code division multiple access (CDMA) is used as a radio access system of a base station used in a mobile communication system.
When ss) is applied, the receiver of the base station performs RAKE reception to improve reception quality. The RAKE reception is a technique for allocating a finger to a corresponding path position based on a delay profile acquired at the time of signal reception and improving reception quality by maximally ratio combining reception signals obtained from the allocated finger.

[0004] Usually, the number of fingers that can be allocated in a base station receiver is finite. Therefore, when there are a plurality of paths between the transmission and reception between the mobile station transmission and the base station reception, the finger is allocated from the path having the highest reception level.
Further, even if there is a margin in the number of fingers that can be allocated, for a path whose reception level does not fall within a predetermined RAKE threshold (defined by the level difference from the path having the maximum reception level), Fingers are not allocated. Here, when performing polarization diversity reception using a vertically polarized antenna and a horizontally polarized antenna having different polarization planes at the base station, for example, the following two methods are conceivable for allocating the fingers: Can be

[0005] Method 1. Path detection is performed for each antenna branch, and fingers are assigned in descending order of reception level from the paths obtained by the detection.

Method 2. First, path detection is performed on the vertical antenna branch, and fingers are assigned in order from the path having the highest reception level. Fingers are assigned to one horizontal antenna branch at the same positions as the finger positions assigned to the vertical antenna branches.

[0007]

In the finger assignment method 1 described above, since the path detection is performed independently for each antenna branch, the fingers cannot be assigned efficiently. In the case of the finger assignment method 2 described above, it cannot always be said that the path of the horizontal antenna branch exists at the same position as the path position detected in the vertical antenna branch. Therefore, a finger may be assigned to a position where a path does not exist. In such a case, communication quality is degraded.

Therefore, a first object of the present invention is to provide a finger assignment method for RAKE reception that can efficiently detect paths of both antenna branches and perform finger assignment at the time of polarization diversity reception. is there.

A second object of the present invention is to provide an apparatus capable of performing path detection and finger assignment according to such a finger assignment method.

[0010]

In order to solve the above-mentioned first problem, according to the present invention, there is provided a CD for simultaneously performing a plurality of communications using signals of the same frequency band.
In MA communication, when a predetermined signal spread-modulated from the transmission side is received by polarization diversity reception using a first polarization antenna branch and a second polarization antenna branch having different polarization planes, the received signal is received. In the RAKE reception finger assignment method for assigning a RAKE reception finger to a path, the reception path is detected in the first polarization antenna branch, and the second path is determined based on the detected path.
, And path assignment for RAKE reception is performed on the detected path.

In the finger assignment method as described above, the path detection and finger assignment of the second polarization antenna branch are performed based on the path detection result of the first polarization antenna branch. The path detection result obtained from the antenna branch of the first polarization includes information on the path position and the path level. The path detection of the antenna branch of the second polarization is executed after a path to be detected is narrowed down in advance based on information on the position of this path and its path level. That is, it is not necessary to perform the process related to the path detection for the paths that are not to be detected, so that the path can be detected efficiently. Also, by assigning RAKE receiving fingers to the detected paths, it is possible to further improve the quality of the received signal when RAKE combining is performed. Further, since at least one device is used for path detection, the cost of the device can be reduced.

In view of the fact that the path detection range of the antenna branch of the second polarization is provided so that path detection can be performed more quickly, the present invention provides the above-mentioned RAKE receiving apparatus. In the finger assignment method, a detection range of a path to be detected in the second polarization antenna branch is set based on the path position detected in the first polarization antenna branch, and the set path is set. It is configured to perform path detection of the second polarization antenna branch in the detection range.

In such a RAKE receiving finger assignment method, first, a path is detected from a delay profile obtained in the antenna branch of the first polarization, and the second polarization is determined based on the result of the detected path position. The path detection range of the antenna branch is set. Since the path detection of the antenna branch of the second polarization is performed in the set path detection range, the path detection can be performed with relatively high accuracy, and the limited path detection range is searched. Path detection can be performed relatively quickly.

From the viewpoint that the path to be detected can be efficiently detected by limiting the detection target path of the antenna branch of the second polarization, the present invention provides the above-mentioned RAKE. In the receiving finger allocating method, the reception level of each path obtained in the first polarization antenna branch is compared with a predetermined threshold, and the comparison gives a predetermined level difference from the level of the path having the maximum reception level. Determine the path that is expected to be within the range,
The path obtained by the determination may be regarded as a path to be detected in the second polarization antenna branch, and the path may be detected.

In such a RAKE receiving finger assignment method, a level threshold between the antenna branch of the first polarization and the antenna branch of the second polarization is set, and the threshold and the first threshold are set.
The maximum number of paths to be detected in the second polarization antenna branch can be narrowed down (limited) in advance by comparing the path levels obtained in the polarization antenna branch. In other words, by performing the above-mentioned comparison, a path that is expected not to be within the RAKE threshold is excluded from path detection targets in advance, so that the path detection of the antenna branch of the second polarization can be efficiently performed.

According to a fourth aspect of the present invention, in the method of allocating a finger for RAKE reception, the predetermined threshold is set to a first polarization antenna branch and a second polarization antenna. It is configured to be set based on the level difference between branches.

From the viewpoint that a RAKE receiving finger can be assigned to the path of the antenna branch of the second polarization detected as described above, the present invention provides the above-described RAKE receiving finger. The receiving finger assignment method is configured to assign a RAKE receiving finger to a path detected in the second polarization antenna branch.

From the viewpoint of allocating a limited number of RAKE receiving fingers without waste, according to the present invention, in the RAKE receiving finger allocating method, detection is performed by the first polarization antenna branch. R
After allocating the AKE receiving finger, when the path detection of the second polarization antenna branch is performed based on the path detection result of the first polarization antenna branch, the finger to which the detected path can be allocated is assigned. If the number does not exceed the permissible number, the RAKE receiving finger is allocated to the path detected in the second polarization antenna branch, and the detected path exceeds the permissible number of fingers that can be allocated. If so, the path level detected in the second polarization antenna branch is compared with the path level of the first polarization antenna branch to which a finger has already been assigned, and the comparison selects the path level in descending order of the path level. It can be configured to reassign the assigned paths up to the number of fingers that can be assigned.

In such a RAKE receiving finger assignment method, when assigning fingers, a comparison is always made with the maximum assignable finger number, and if the maximum assignable finger number is exceeded, the path level is high. Fingers are assigned in order. That is, even in such a case, a path is selected so that the reception quality when the maximum ratio combining is performed is the best, and fingers are assigned to the path. For this reason, according to the present invention, path selection is performed such that the reception level at the time of maximum ratio combining becomes high quality regardless of whether the number of detected paths exceeds the maximum number of fingers that can be allocated, A signal having good reception quality can be supplied to a signal processing unit and the like at the next stage.

From the viewpoint that communication with a predetermined partner can be performed when a finger is assigned to the path detected by the first polarization antenna branch, the present invention provides a communication system comprising: In the above RAKE receiving finger assignment method, after the RAKE receiving finger is assigned to the path detected by the first polarization antenna branch, communication is established with a predetermined partner.

According to another aspect of the present invention, there is provided a CDMA communication system for simultaneously performing a plurality of communications using signals in the same frequency band.
When a predetermined signal spread-modulated from the transmission side is received by the polarization diversity reception using the first polarization antenna branch and the second polarization antenna branch having different polarization planes, the received reception path is In an apparatus for allocating fingers for RAKE reception, a first path detecting means for detecting the reception path at a first polarization antenna branch, and a second polarization antenna branch based on the detected path. It can be configured to include second path detecting means for performing path detection, and finger allocating means for allocating fingers for RAKE reception to the detected path.

[0022]

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

A mobile communication system to which the method of allocating a finger for RAKE reception at the time of polarization diversity reception in CDMA communication according to an embodiment of the present invention is applied, for example, is shown in FIG.
It is configured as shown in FIG.

Referring to FIG. 1, the mobile communication system includes:
For example, the mobile communication system is a CDMA cellular mobile communication system and includes a mobile station 10 (such as a mobile phone), a base station 20, and a network device 30 (for example, an exchange device). In the present mobile communication system, the mobile station 10 is
Wireless communication, and voice communication and non-call communication with another terminal (such as a mobile phone) via the network device 30 can be performed.

The base station 20 has a receiver 24 (Rx) for performing RAKE reception in addition to a transmitter 23 (Tx) of a normal base station. In this embodiment, the receiver 24 will be described as a RAKE receiver. The base station 20 employs a "polarization diversity" technique for performing diversity using antennas having different polarization planes. The polarization diversity includes a form using linear polarization and a form using circular polarization. In the embodiment using linear polarization, a first polarization antenna 21 (hereinafter, referred to as a vertical antenna branch) and a second polarization antenna 22 (hereinafter, referred to as a horizontal antenna branch) for performing polarization diversity reception at the base station 20. Is provided. In the embodiment using circular polarization, a right-handed polarization antenna (for example, the first antenna shown in FIG. 1) for performing polarization diversity reception at the base station 20 is used.
And a left-handed polarization antenna (e.g., corresponding to the second polarization antenna in FIG. 2). Hereinafter, the embodiment of the present invention will be described by taking as an example a case where the base station 20 applies polarization diversity using linear polarization.
In this example, the first polarization antenna 21 in FIG. 1 corresponds to a vertical polarization antenna, and the second polarization antenna 22 corresponds to a horizontal polarization antenna. In addition, the form of the antenna used for performing polarization diversity may be a form in which both antennas are individually prepared, or a form in which both antennas are formed in one antenna. The present invention is applied regardless of which form is used.

Next, the RAKE receiver 2 of the base station 20
4 will be described with reference to FIG.

In FIG. 2, the RAKE receiver 24 includes a path detecting unit 24 ₁ , a vertical antenna branch finger allocating unit 24 ₂ , and a horizontal antenna branch finger allocating unit 2
4 _3, finger assignment information unit 24 _4, storage unit (memory)
24 _5, the maximum ratio combining unit 24 _6, and an antenna branch switching unit ₂₄ 7, 24 _8. The information relating to the path detection range and the threshold value of the vertical antenna branches 21 and between the horizontal antenna branch 22 levels used in detecting paths in the storage unit 24 ₅ are stored. This path detection range, vertical antenna branch 21 and horizontal antenna branch 2
The threshold between the two levels will be described later. In the RAKE receiver 24, the signal spread-modulated by the mobile station 10 is received by the antennas of both branches, the path of the received signal is detected, and a finger is allocated to the detected path to obtain a maximum ratio. Synthesis is performed.

The RAKE receiver 24 assigns fingers for RAKE reception when the aforementioned polarization diversity is applied to the base station 20, for example, according to the flowchart shown in FIG. In describing this flowchart will be described with reference to the respective hardware RAKE receiver 24 in FIG. 2 ₍₂₄ 1-24 _8).

[0029] First, when a spread modulated signal transmitted from the mobile station 10 receives at both antenna branch, antenna branch switching section ₂₄ 7 of the RAKE receiver 24, 24 ₈ path detector 24 ₁ vertical antenna branch 21 Connect to the system. Path detecting unit 24 ₁ performs path detection (S1) of the vertical antenna branch 21 from the delay profile of the signal received by the vertical antenna branch 21 connected. Here, the number of paths detected by the vertical antenna branch 21 is defined as _Np1 . Finger allocator (V) (V: V
ertical vertical) 24 ₂ performs the assignment of fingers to the paths that are detected as described above, and stores the number of fingers assigned to (N _f) in a predetermined memory (S2). Normal,
The processing steps were carried out in (S2), the number of paths fingers assigned N _f is assigned the maximum possible number of fingers N
It is _fmax or less _{(N f} ≦ _{N fmax).} At this time,
Finger assignment unit (V) between transmission and reception by using only signals received by the finger assigned in 24 _2, i.e., the base station 20
Communication between the mobile station 10 and the mobile station 10 may be started.

[0030] When the finger assignment unit (V) 24 ₂ finishes finger assignment vertical antenna branches 21 system,
Information about the assigned fingers and sends a finger assignment information unit 24 _4. This information finger assignment information unit 24 _4, generates the information and level information of the finger from the information on the finger received relating to the position of fingers allocated by the finger allocation unit (V) 24 ₂ (S3)
And it sends to the path detector 24 ₁ in.

Subsequently, the antenna branch switching unit 2
4₇, 24₈Switch of the path detection unit 24₁But water
It is connected to a flat antenna branch system 22. Path detector 2
4₁Contains the finger assignment information section 24 described above.₄from
Finger information and storage unit 24₅Path stored in advance
Information indicating conditions for detection, in this case, path detection range
And information on the level threshold between antenna branches is input
(S4) A path is detected (S5). That is, horizontal
The path detection of the tener branch 22 is a predetermined path detection.
Implemented within range and antenna branch level threshold conditions
It is. Here, it is detected by the horizontal antenna branch 22.
Pass N_p2Is defined. Path detected within the above conditions
Is a finger assignment unit (H) (H: Horizontal horizontal) 24
₃Is performed to assign fingers. At this time,
Of the vertical antenna branch 21 to which the finger is assigned
Path N_p1Is the finger assignment information section 24₄Path detection from
Part 24₁Has been notified. Path detector 24₁Is this
S_p1And the path detected by the horizontal antenna branch 22
Number N_p2And the result of the addition is
Number of large fingers N_fmaxJudge whether or not
(S6). Path detector 24₁In this determination (S6),
N_f+ N_p2Finger number N to which the sum of
_fmaxIs not exceeded (Y in S6)
ES) on the path detected by the horizontal antenna branch 22
Finger allocator (H) to allocate fingers to
24₃Notify. This finger assignment unit (H) 24₃
Assigns a finger to the path detected above.
U.

On the other hand, in the above judgment (S6), N_f+ N_p2of
Maximum number of fingers N to which sum can be assigned _fmaxExceeded
Is obtained (NO in S6), the path detection unit 24₁Is
The maximum filters in descending order of the path level detected in both branches
Nga number N_fmax(S7) and select the path
Each finger to assign a finger to the
Gas allocation unit (V) 24₂, (H) 24₃Notify. the above
Finger allocator (V) 24₂, (H) 24₃Is the above selection
Assign a finger corresponding to the performed path.

[0033] The above-decided received signal obtained at each finger assigned based on (S6) the maximum ratio combining unit 24 ₆
, Is subjected to maximum ratio combining (RAKE combining) and sent to the next stage.

As described above, in the RAKE receiving finger assignment method at the time of polarization diversity reception according to the present invention, the path detection of one horizontal antenna branch 22 is performed based on the path detection result detected by the vertical antenna branch 21. .
Therefore, the path detecting unit 24 ₁ can be reduced device cost because it is possible to perform path detection of the horizontal antenna branches 22 if provided at least one.

As described above, the horizontal antenna
The storage unit 24 detects the path of the ₅Preset to
Path detection range and the threshold level between antenna branches
used. Horizontal antenna branch 2 with high speed and high accuracy
2 to realize the path detection within
The setting value of the threshold value between tena branches is becoming important
You. Next, this path detection range and the level between antenna branches
The method for determining the threshold value of the rule will be described. First, the above path
Diagram showing the relationship between the detection range and the threshold value between antenna branches
4, the path detection range and the antenna
A method of determining a threshold value between lunch levels will be described.

1. FIG. 4A shows a delay profile obtained by the vertical antenna branch 21. The relationship between the path detection range and the threshold value of the level between the antenna branches is shown in FIG.
The horizontal axis represents the delay time (μs), and the vertical axis represents the reception level (dB). From this delay profile, three paths are detected within the RAKE threshold ΔL (dB) among the paths received by the vertical antenna branch 21. In addition, each path includes a first path (P1), a second path (P2),
The third pass (P3) is set, and fingers are assigned to these passes. Furthermore, the position and level of the path assigned to fingers _{(P1, t 1), (} P2, t 2), is (P3, _{t 3).}

Path detection in the horizontal antenna branch 22
As described above, the position and the level
Used as gas allocation information. In addition, the path detection
Is the path detection range and the level threshold between antenna branches
It is performed under conditions. RAKE reception of the base station 20 shown in FIG.
The machine 24 is a storage unit 24₅And the storage unit 24 ₅
The path detection range and the level threshold between antenna branches are
Is memorized. The path detection range is the range for the path position.
It is an enclosure and a plurality is prepared. In FIG. 4 (b), the vertical antenna
Horizontal unbalance determined based on branch path detection results
Path detection range Δt of tena branch₁, Δt₂, Δt₃of
An example is shown. Here, the first pass (P1) to the first pass
Δt for 3 passes (P3)₁, Δt₂, Δt₃Threshold
Value is defined. Also, in FIG.
Constant level Δα (dB) is defined as the level threshold between tena branches
Have been.

For example, the path detection of the horizontal antenna branch 22 shown in FIG.
The t ₁ , Δt ₂ , Δt ₃ and the inter-antenna branch level threshold are determined as follows using a constant value Δα.

Firstly, narrowing down the path of the horizontal antenna branches 22 by using the level and antenna branch between level threshold of paths assigned to fingers in the vertical antenna branch 21 is performed in the path detector 24 _1. Specifically, if the level of the j th path was _{P j,} refinement pass, _{P j} - performing than _{Δα ≧ P 1 -ΔL (1)} . In other words, Equation (1) above selects only those paths that are expected to fall within the RAKE threshold based on the level of the vertical antenna branch 21 first path. For example, FIG.
In the example of (b), only the third path (P3) is deleted from the candidates for path detection. The path detector 24 _1, by using the position information and path detection range intended for remaining path detection candidate detecting path in the horizontal antenna branches 22. In the example of FIG. 4B, the first path and the second path are path detection candidates. The path detection is specifically the position of the k th path tk, the path detection in the range of t _k ± _{Δt k} / 2 is the path detection range with respect to the path when a Delta] t _k.

As described above, when the path detection of the horizontal antenna branch 22 is performed, by providing the conditions of the path detection range and the level threshold between the antenna branches, the path detection in the branch can be performed accurately and efficiently. . The path detection range and the level threshold between antenna branches can be determined, for example, as follows.

2. Method of Determining Path Detection Range and Threshold of Inter-Antenna Branch Level 2.1 Method of Determining Path Detection Range The path detection range is determined, for example, by the vertical antenna branch shown in FIGS. 5 (a), 5 (b) and 6 (c). It is determined on the basis of an example of an outdoor experiment result (urban area) for the difference between the position and the level of the path received by the horizontal antenna branch 21 and the horizontal antenna branch 22. 5 (a), 5 (b) and 6 (c) show the cumulative probability [%] (vertical axis) of the path position received by the horizontal antenna branch 22 based on the path position received by the vertical antenna branch 21. The horizontal axis represents the path position difference (chip ×
10). FIG. 5A shows the difference between the first paths, and FIG.
FIG. 6B is a diagram illustrating a difference between second paths, and FIG. 6C is a diagram illustrating a difference between third paths. Note that θ in FIGS. 5A, 5B, and 6C is an angle between the ground of the mobile station 10 antenna and the vertical direction. 5 (a), 5 (b) and 6
Comparing the results in (c), it can be seen that the deviation of the path position becomes larger as the paths with smaller levels become closer. For example, as shown in FIG. 6C, it can be seen from the cumulative probability [%] in FIG. 6 that the difference in the path position between the paths (P3) having a small level is largely shifted. Accordingly, the present invention sets the path detection range under conditions of _{Δt 1 ≦ Δt 2 ≦ Δt 3} ≦ ···. In other words, the detection range is narrowed between high-level paths,
By making the path detection range wide between paths with small levels, it is possible to perform path detection accurately and efficiently.

2.2 Method of Determining Level Threshold Between Antenna Branches The level threshold between antenna branches is determined, for example, by the average level difference [dB] between paths obtained by both antenna branches shown in FIG. Angle θ (degre
e].

In FIG. 6, the vertical axis represents the average level difference, and the horizontal axis represents the inclination angle θ of the mobile station 10 antenna. When the average level difference is positive, the level of the vertical antenna branch is larger than the level of the horizontal antenna branch. Also, the tilt angle θ of the mobile station 10 antenna is 0.
If the angle is between 45 ° and 45 ° (corresponding to the inclination when a normal mobile station is used), the level of the vertical antenna branch is higher for any path (first to third paths) Can be seen from this figure. Therefore, when the level threshold between antenna branches is set in the present invention, it is determined based on the condition of 6 [dB] ≧ Δα ≧ 0 [dB] and the RAKE threshold ΔL.
It should be noted that the number of path candidates detected in the horizontal antenna branch decreases as Δα increases.

As described above, the path detection of the horizontal antenna branch 22 is performed by the vertical antenna branch 21.
Is performed based on the path detection result (information on the path position and the path level) detected in step (1). In the present invention, the number of paths to be detected is limited by using a threshold value between antenna branches provided in advance, and a path detection range is set in advance, so that a path search may be performed within the limited range. As a result, the path of the horizontal antenna branch 22 can be accurately and efficiently detected. As a result, according to the method of allocating fingers for RAKE reception at the time of polarization diversity reception according to the present invention, detection can be performed in comparison with the related art in which fingers cannot be efficiently allocated to the detection paths of both antenna branches. The path to be detected is detected with high accuracy and high speed. Therefore, the time required for path detection can be improved. In addition, since accurate path detection can be realized, the efficiency of finger assignment can be improved.

[0045] In the above example, the path detection function of the path detection portion 24 ₁ of the RAKE receiver 24 corresponds to the path detecting means and the first path detection means and the second path detection means, the path detection unit section 24 ₁ of path comparison and determination function corresponding to the path determining means and the first and second level comparator means. Finger assignment unit (V) 24 _2, finger assignment unit (H) 24 ₃ corresponds to the finger assignment means and the first finger assignment means and the second finger allocation unit, the memory function path detection range of the storage unit 24 ₅ It corresponds to the setting means and the antenna branch level threshold setting means. Further, the maximum ratio combining unit 24
_{In FIG. 6} , the received signal combining function corresponds to the communication establishing means. This represents that the communication established from the received signal RAKE combined in the same part 24 ₆ can be performed.

[0046]

As described above, claims 1 to 7 have been described.
According to the described invention, the path detection of the horizontal antenna branch is executed based on the path detection result of the vertical antenna branch, that is, the finger assignment information. That is, the number of paths to be detected is limited in advance using the threshold value between the levels of both antenna branches, and the path detection range is set in advance, and path detection is performed within these conditions. Therefore, the path detection of the horizontal antenna branch can be performed efficiently because the path to be detected is limited in advance. Furthermore, since at least one device is used for path detection, the device cost can be reduced.

Further, according to the present invention as set forth in claims 8 to 17, it is possible to realize a base station capable of performing finger assignment according to the above-described RAKE receiving finger assignment method.

[0048]

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a mobile communication system to which a RAKE receiving finger assignment method according to an embodiment of the present invention is applied.

FIG. 2 shows a diagram of a base station in the mobile communication system shown in FIG.
FIG. 3 is a diagram illustrating a configuration of a RAKE receiver.

FIG. 3 is a flowchart of a finger assignment process for RAKE reception.

FIG. 4 is a diagram illustrating a path detection range and a threshold value of a level between antenna branches.

FIG. 5 is a diagram showing path position differences (a) and (b) between a vertical antenna branch and a horizontal antenna branch.

FIG. 6 is a diagram showing a path position difference (c) between a vertical antenna branch and a horizontal antenna branch. (Continuation of FIG. 5)

FIG. 7 is a diagram illustrating a path level difference between a vertical antenna branch and a horizontal antenna branch.

[Explanation of symbols]

10 mobile station 20 the base station 21 first polarization antenna (vertically polarized antenna) 22 second polarization antenna (horizontally polarized antenna) 23 transmitter (Tx) 24 RAKE receiver (Rx) 24 ₁ path detection unit 24 ₂ vertical antenna branch for finger assignment unit 24 ₃ horizontal antenna branch for finger assignment unit 24 ₄ finger assignment information unit 24 ₅ storage section (memory) 24 ₆ maximum ratio synthesizer 24 ₇ antenna branch switching unit 24 ₈ antenna branch switching unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K022 EE01 EE31 5K052 AA01 BB02 CC06 DD03 EE13 FF29 5K059 CC05 DD12 EE02 5K067 AA33 AA41 BB04 CC10 CC24 DD42 DD44 EE02 EE10 HH22 KK03

Claims (17)

[Claims] In a CDMA communication in which a plurality of communications are simultaneously performed using a signal in the same frequency band, a predetermined signal spread-modulated from a transmitting side is combined with a first polarization antenna branch having a different polarization plane and a second polarization antenna branch. When polarization diversity reception is performed using a polarization antenna branch, RA is applied to the received reception path.
In the RAKE reception finger assignment method for assigning a finger for KE reception, the reception path is detected in the first polarization antenna branch, and the second polarization antenna branch is detected based on the detected path. A RAKE reception finger assignment method for performing path detection and assigning RAKE reception fingers to the detected path. 2. The method of allocating fingers for RAKE reception according to claim 1, wherein a path of the second polarization antenna branch is detected based on a path position detected by the first polarization antenna branch. A RAKE receiving finger assignment method for setting a path detection range and detecting a path of the second polarization antenna branch in the set path detection range. 3. The method of allocating fingers for RAKE reception according to claim 2, wherein the reception level of each path obtained in the first polarization antenna branch is compared with a predetermined threshold value, and the maximum reception level is determined by the comparison. A path which is expected to fall within a given range from the level of the path having the predetermined level is determined, and the path obtained by the determination is regarded as a path to be detected by the second polarization antenna branch. RAKE receiving finger assignment method that performs path detection. 4. The RAKE receiving finger allocating method according to claim 3, wherein said predetermined threshold value is set based on a level difference between said first and second polarization antenna branches. Finger assignment method. 5. The RAKE receiving finger assigning method according to claim 2, wherein the RAKE receiving finger is assigned to a path detected in the second polarization antenna branch. Assignment method. 6. The RAKE receiving finger allocating method according to claim 1, wherein a RAKE is added to a path detected by the first polarization antenna branch.
After allocating the receiving fingers, when the path detection of the second polarization antenna branch is performed based on the path detection result of the first polarization antenna branch, the number of fingers to which the detected path can be allocated If the value does not exceed the allowable value, the RAKE receiving finger is assigned to the path detected in the second polarization antenna branch, and the detected path exceeds the allowable number of assignable fingers. If this is the case, the path level detected in the second polarization antenna branch is compared with the path level of the first polarization antenna branch to which a finger has already been assigned. RAKE receiving finger assignment method for reassigning up to the number of fingers that can assign a given path. 7. The RAKE receiving finger assigning method according to claim 6, wherein the path detected by the first polarization antenna branch includes a RAKE
A RAKE receiving finger assignment method for establishing communication with a predetermined partner after assigning receiving fingers. 8. In CDMA communication in which a plurality of communications are simultaneously performed using signals of the same frequency band, a predetermined signal spread-modulated from a transmitting side is combined with a first polarization antenna branch having a different polarization plane and a second polarization antenna branch. When polarization diversity reception is performed using a polarization antenna branch, RA is applied to the received reception path.
An apparatus for allocating fingers for KE reception, comprising: first path detection means for detecting the reception path in the first polarization antenna branch; and an antenna for the second polarization based on the detected path. An apparatus comprising: second path detecting means for detecting a path of a branch; and finger allocating means for allocating a finger for RAKE reception to the detected path. 9. The apparatus according to claim 8, wherein a detection range of a path to be detected by the second polarization antenna branch is determined based on a path position detected by the first polarization antenna branch. An apparatus comprising: a path detection range setting unit to be set; and a path detection unit to detect a path of the antenna branch of the second polarization in the set path detection range. 10. The apparatus according to claim 9, wherein first level comparing means for comparing a reception level of each path obtained in said first polarization antenna branch with a predetermined threshold value, Path determination means for determining a path that is expected to fall within a given range from a level of a path having a reception level; and determining the path obtained by the determination by the second polarization antenna branch. A path detection unit that performs path detection by regarding the path as a path to be detected. 11. An antenna branch level threshold setting means according to claim 10, wherein said predetermined threshold is set based on a level difference between said first polarization antenna branch and said second polarization antenna branch. An apparatus having 12. The apparatus according to claim 9, further comprising finger allocating means for allocating a RAKE receiving finger for a path detected by said second polarization antenna branch. 13. The apparatus according to claim 8, wherein a path detected by said first polarization antenna branch is raked.
After allocating the receiving finger, path detection of the second polarization antenna branch is performed based on the path detection result of the first polarization antenna branch, and an allowable value of the number of fingers to which the detected path can be allocated If not, a first finger allocating means for allocating RAKE receiving fingers to the path detected in the second polarization antenna branch, and an allowable number of fingers to which the detected path can be allocated. A second level comparing means for comparing the path level detected in the second polarization antenna branch with the path level of the first polarization antenna branch to which a finger has already been assigned if the value exceeds the value; A second finger allocating means for reallocating fingers to the number of fingers that can be allocated to the paths selected in descending order of the path level. Place. 14. The apparatus according to claim 13, wherein RAKE is added to a path detected by said first polarization antenna branch.
An apparatus having communication establishment means for establishing communication with a predetermined partner after allocating reception fingers. 15. An apparatus for receiving a predetermined signal spread-modulated from a transmission side by means of polarization diversity, wherein the base station performs finger assignment for RAKE reception for the received path. The described device. 16. The base station according to claim 15, wherein the polarization plane of the first polarization antenna branch is a vertical knitted wave and the polarization plane of the second polarization antenna branch is a horizontal polarization. 17. The base station according to claim 15, wherein the polarization plane of the first polarization antenna branch is a left-handed helical wave and the polarization plane of the second polarization antenna branch is a right-handed polarization.