JP2000187051A - Method for detecting gradient - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect a power gradient of an RF signal under a noise environment. SOLUTION: Power points of a first and a second power point groups to be inspected in relation to an RF signal burst of an RF signal are determined. A power PA, PB included in an area of the first, second power point group is calculated at first, second power point group. The calculated powers PA and PB are compared with each other, whereby a gradient of the first and second power point groups is calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to gradient detection of RF signals, and more particularly, in a preferred embodiment, gradient detection and identification of power bursts, such as adjacent GSM power bursts.

[0002]

2. Description of the Related Art GSM (Global System)
for Mobile Communication
s) is a global standard for digital mobile phones. G
One of the problems with SM applications has been to obtain a potentially noisy signal, or RF envelope, or other efficient way to determine the slope of such a signal. Traditional methods are prone to noise errors. It would be desirable to provide an improved method for detecting RF signals in the presence of noise.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved method for detecting the gradient of an RF signal in a noisy environment, especially for RF signals close to each other, such as GSM power bursts. An object of the present invention is to provide a method for detecting a gradient of a power burst.

[0004]

Once the positive and negative slopes of the RF signal have been determined, power bursts can be identified and extracted. One of the preferred embodiments is GSM
Can be implemented by application. On the other hand, in another embodiment, the GS
M, PDC (Pacific Digital Cell)
ullar), NADC (North American)
Digital Cellular) is a part of it and is applicable to the general class of time division multiple access (TDMA) signals.

In one preferred embodiment of the present invention, rather than determining a simple difference (△) between power points A and B, which are susceptible to noise errors, a group of power points (hereinafter simply “group”) is used.
Also called. ) To determine the slope,
Unlike in other edge detectors. The power calculation for the power point cloud is the integration of the power points. This integral acts like a selective moving average filter. The gist of the present invention is:
1) Filtering or averaging is not required for the entire signal before gradient detection, but only for areas that exceed a specified threshold (ie, selective integration increases computational efficiency). And 2) the gradient detection is advanced over the signal to find the rising and falling edges of the burst, and once these edges are identified, the burst will be identified and extracted. The specified power change must occur for discrimination, further reducing errors in edge detection in a noisy environment.

In the method of the present invention, a signal gradient at a given power point is obtained in a noise environment. Rather than taking the simple difference between power points, the method of the present invention:
Compute the slope by comparing the power around the desired power point.
The width of the comparison is an important factor in noise reduction. If the width is too wide, the signal may be rejected. Another important factor is the amount of power change (ie, delta).

[0007] Other objects, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, will now be described in detail. The description of the present invention will be made with reference to the preferred embodiments, but, of course, is not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications, and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.

FIG. 1 is a timing diagram of a GSM power burst showing the y-axis as the RF power of the GSM signal and the x-axis as time. Obviously, this GSM signal is a series of repeated power bursts.

FIG. 2 is a timing chart for explaining the method of the present invention. The method includes the following sequence of steps:

The method of the present invention described with reference to FIG. 2 detects a gradient for a proximity GSM power burst as shown in FIG.

First, in a first step, a power point to be tested is selected based on a power level threshold.

In the second step, each power P included in the power point cloud area A and the power point cloud area B shown in FIG.
It is to calculate A and PB. The width of this power point cloud area is
The parameters set by the application software are shown as Δt.

In the next step, the gradient is calculated as follows: (a) If (difference between PA and PB) <e, the gradient is flat (ie, the gradient is 0; sample 3 in FIG. 2) Case). Here, e is the minimum epsilon exceeding 0.0, that is, the minimum power change amount, and is specified by the application software. (B) If (PA> PB), the slope is negative (-) (for sample 1 in FIG. 2). Here, PA is the power of the power point group before the power point to be tested, and PB is the power of the power point group after the power point to be tested. The power point cloud area before the point, and B becomes the power point cloud area after the power point). (C) If (PA <PB), the slope is positive (+) (see sample 2 in FIG. 2). (D) Fluctuations in Δt and e (change in power amount) may affect the noise removal level.

The method of the present invention can be implemented in a computer or DSP using a common programming language (eg, C, C ++, etc.) or programmable instructions for a DSP IC using a data array representing time versus amplitude. It is.

The method of the present invention provides a method for detecting other edges in terms of examining a group of power points and determining a gradient, as opposed to a simple difference (電力) between the power points, which is prone to noise errors. It is different from a bowl. The gist of the present invention is that 1) filtering or averaging is not required for the entire signal before gradient detection, but only for areas that exceed a specified threshold (computational efficiency due to selective integration) 2) the point at which the power change (delta) exceeds the value provided by the application software (epsilon); and 3) the gradient detection finds the rising and falling edges of the burst, so that the entire signal is Once these edges have been identified, the burst is identified and contains the points to be extracted.

FIGS. 3A and 3B are timing diagrams illustrating a traditional method as compared to the method of the present invention. FIG. 3A illustrates a false negative slope that may occur when using the traditional method, and FIG. 3B illustrates the method of the present invention. In the method of the present invention shown in FIG. 3B, PA <P at a power point having a slope generally indicating a rising edge.
B is confirmed. In the traditional way, Figure 3A
A falling edge is indicated as shown in FIG.

In the method of the present invention, the slope of a signal at a predetermined power point in a noise environment is measured. Rather than measuring just the difference (delta) between the power points, the method of the present invention calculates the slope by comparing the power around the desired power point. The time width used for comparison is an important factor in noise removal. If the width is too wide, the signal may be rejected. The amount of power change is another important factor.

FIG. 4 is a timing chart of an RF signal for explaining burst extraction according to the present invention. In the case of FIG. 4, the gradient is not calculated for the RF signal before the time T1 because it is less than the threshold value. At time T1, the burst exceeds the threshold, so the delta power gradient detection method according to the invention is applied to the RF signal to find a positive or rising edge. Similarly, prior to time T2, a delta power gradient detection method according to the present invention is applied to the RF signal to find a negative or falling edge. The gradient detector can scan the entire signal between times T1 and T2 to identify bursts and extract the bursts. After time T2, the slope is not calculated after time T2 because the RF signal falls below the threshold.

The foregoing description of specific embodiments of the present invention has been presented for purposes of illustration and description.
It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed, and, of course, many modifications and variations are possible in light of the above teaching. For example, one of the embodiments is applicable for GSM applications. On the other hand, in other embodiments, GSM, PDC (Pacific Digital
The present invention can be applied to a general class of time division multiple access (TDMA) signal of which cellular, NAND, and the like are a part. These embodiments most clearly describe the principles of the present invention and its practical applications, and will allow others skilled in the art to make various modifications to suit the particular intended application. And to make the most effective use of the various embodiments,
Explained. It is intended that the scope of the invention be defined by the following claims and their equivalents: In the following, some of the embodiments of the present invention are shown to assist in the broad practice of the present invention.

(Embodiment 1) A method for detecting a gradient in an RF signal, comprising the steps of: determining power points of first and second power point groups to be inspected for an RF signal burst of the RF signal; Calculating power included in the first and second power point cloud areas (A, B) in each of the second power point cloud; and gradients of the first and second power point cloud from the power Calculating the gradient.

(Embodiment 2) When the RF signal is at least G
The gradient detection method according to embodiment 1, wherein the gradient detection method belongs to one of a class of time division multiple access signals including SM, PDC, and NADC. (Embodiment 3) The gradient detection method according to embodiment 2, wherein if the difference between the powers is smaller than a specified power change amount, the gradient is determined to be flat. (Embodiment 4) When the power included in the power point group area A is larger than the power included in the power point group area B, a step of determining that the gradient is negative is included. The gradient detection method according to the third embodiment.

(Embodiment 5) When the power included in the power point group area A is smaller than the power included in the power point group area B, a step of determining that the gradient is positive is included. The gradient detection method according to embodiment 3, which is characterized by the following. (Sixth Embodiment) A gradient detection method according to the fifth embodiment, further comprising a step of detecting a rising edge and a falling edge of the RF signal burst to enable the identification of the RF signal burst. (Embodiment 7) The gradient detection method according to embodiment 6, further comprising the step of extracting the identified signal burst.

[Brief description of the drawings]

FIG. 1 is a timing diagram of a GSM power burst.

FIG. 2 is a timing chart for explaining the method of the present invention.

FIG. 3A is a timing diagram illustrating a specific example of the method of the present invention.

FIG. 3B is a timing diagram illustrating a specific example of the method of the present invention.

FIG. 4 is a timing chart for explaining burst extraction according to the present invention;

[Explanation of symbols]

 ──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant 399117121 395 Page Mill Road Palo Alto, California U.S.A. S. A.

Claims (1)

[Claims] 1. A method for detecting a gradient in an RF signal, the method comprising: determining power points of first and second groups of power points to be tested for RF signal bursts of the RF signal; First in each of the power point clouds
A gradient detection method, comprising: calculating power included in a second power point cloud area; and calculating gradients of the first and second power point cloud from the power.