CN117081687A

CN117081687A - RSSI data sampling method

Info

Publication number: CN117081687A
Application number: CN202311305794.8A
Authority: CN
Inventors: 陈亮; 梁宏明; 黄强; 黄大峰
Original assignee: Sichuan Silingke Microelectronics Co ltd
Current assignee: Sichuan Silingke Microelectronics Co ltd
Priority date: 2023-10-10
Filing date: 2023-10-10
Publication date: 2023-11-17
Anticipated expiration: 2043-10-10
Also published as: CN117081687B

Abstract

The invention discloses an RSSI data sampling method, which comprises the following steps that a calculates the numerical relation between RG and RSSI; b adjusting the filter gain system, setting the symbol power P _S The value range is taken, and the RSSI value is output; c, subtracting RSSIs obtained from adjacent gears to obtain a real stepping value of the filter gain system; d calculating P _S Relation to RSSI, e versus receiver symbol power P _S The value is processed; f, recording and storing the values of RG and RAG and the value of the data length K, and calculating to obtain the RSSI value. The invention is implemented by the method of P _S The definition of the gain of the wireless communication system is ensured, so that signals with proper size can be obtained for integration to output accurate RSSI information, and compared with the existing system, the output maximum value inaccurate measurement condition caused by overlarge signal exceeding or approaching to the maximum range can be effectively avoided.

Description

RSSI data sampling method

Technical Field

The invention relates to the technical field of wireless communication, in particular to an RSSI data sampling method.

Background

In wireless communication, RSSI is an important indicator of a communication system, and the indicator characterizes signal strength and can be used for ranging and positioning. A basic wireless communication system should include a transmitter, a receiver, and a host computer involved in the control.

RSSI in wireless communication is affected by factors such as transmitter transmission power TP, transceiver antenna gain AG, receiver filter gain RG, interface cable transmission loss TL, free space transmission loss FL, etc., namely P _RSSI =TP+AG+RG-TL-FL。

However, in actual ranging, the RSSI information we collect always varies irregularly, due to environmental and device effects, whether or not the above factors vary. For the acquisition of RSSI information, we are limited by acquisition equipment, and want to acquire accurate and reliable RSSI information, a device for outputting the RSSI information by using a reasonable acquisition method is indispensable. The existing acquisition methods are roughly classified into the following three types:

the receiver directly integrates the power of the received signal and then outputs the RSSI information, and the method has the advantages of being simplest and easy to realize, and has the defects of no distinguishing ability for the received signal and easy output of an error value.

The receiver divides the received signal into two circuits with different gains, then integrates the power of the two signals to obtain two RSSI information, and determines which one is finally output by comparing the two RSSI information with the preset value of the circuit. The method has the advantages that most of signals can be processed, the output RSSI result is more reliable, and the disadvantage is that the cost of the two-path gain circuit is higher.

The method has the advantages that the circuit can preprocess the RSSI information only by adding the filter module, and finally output the credible RSSI information, and the method has the defects that a set of strict working mode is needed for the filter module, otherwise, the credibility of the finally output RSSI information is not high.

Disclosure of Invention

The invention aims to solve the technical problems of low information accuracy, high cost and the like in the technology, and provides an RSSI data sampling method with higher accuracy, which effectively avoids inaccurate output maximum value measurement caused by overlarge signal exceeding or approaching to a maximum range.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

a RSSI data sampling method comprises the following steps,

step one: values of TP, AG and TL in a communication system are obtained according to formula P _RSSI =tp+ag+rg-TL-FL and the free space loss equation gives FL:

where d is the communication distance, f is the carrier frequency, P _RSSI Representing RSSI value to obtain RG and P _RSSI Is a numerical relationship of (2);

step two: adjusting a filter gain system in a communication system to be the lowest-gear gain, and setting symbol power P _S The range of values is taken, the communication system is started to start to receive and transmit packets, TL is adjusted to enable the symbol power P of the receiver _S The value is in the set value range, the gain of the filter is controlled to be increased from gear to gear, and the RSSI value is output;

step three: subtracting the RSSI values obtained by adjacent gears in the second step to obtain a real stepping value of the filter gain system;

step four: starting the communication system to start transmitting and receiving packets, and in the receiver, the symbol power P _S This can be calculated from the following formula:

，

in the formulaIs the real part, Q is the imaginary part, < >>The number of symbols participating in the integration;

P _S and P _RSSI The relationship is as follows:

（1）

k in the formula represents the data length;

step five: checking receiver symbol power P _S Taking and processing the combined value to ensure P _S In the set value range, then save P _S A value;

step six: the values of the receiving filter gain RG and the receiving antenna gain RAG and the value of the data length K are recorded and saved, and then the RSSI value required to be acquired is obtained according to the formula (1).

Further, in step two, if P _S To be the minimum value in the value range and in the value range, the first RSSI value is output, and then the filter gain is increased step by step, so long as P _S Continuously outputting the RSSI value within the value range; if P _S If the value is larger than the maximum value in the value range, TL is changed by adding a fixed attenuator on the transmission link, so that P is formed _S Is the minimum value in the value range and is in the value range until the gain of the filter is increased to the highest level.

Further, in the first step, the communication system is a communication system including a verification system, and the verification system is a filter gain system.

Further, the transmitting end and the receiving end of the communication system adopted in the first to third steps adopt wired communication, and the communication system adopted in the fourth step adopts wireless communication.

Further, in the fifth step, the specific process of performing the treatment is as follows:

if P _S Outputting the RSSI value within the value range;

if P _S The gain of the filter is increased according to the stepping value obtained in the step three, wherein the gain is smaller than the minimum value in the value range;

if P _S The gain of the filter is reduced according to the stepping value obtained in the step three when the gain is larger than the maximum value in the value range;

finally, the adjusted P is ensured _S The value of (2) is within the range of values.

Compared with the prior art, the invention has the following advantages:

in the scheme, P is passed through _S Is defined to ensure the rationality of the gain of the wireless communication system so that a signal of suitable magnitude can be obtained for integration for transmissionAccurate RSSI information is obtained. Compared with the prior art, the invention has the following advantages:

1. the filter gain system can be adjusted to effectively avoid the condition of inaccurate measurement of the maximum output value caused by overlarge signal exceeding or approaching to the maximum measurement range.

2. Stable inspection of receiver P by adjustment of the filter gain system _S The value is taken, and the problem of inaccurate measurement caused by insufficient accuracy of a system with too small signals can be avoided.

Drawings

Fig. 1 is a schematic block flow diagram of the present invention.

Fig. 2 is a schematic diagram of signal transmission in the acquisition of RSSI data.

FIG. 3 is P _S Schematic diagram of relation with RSSI.

Fig. 4 is a schematic diagram of a symbol power adjustment flow.

Description of the embodiments

To make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention. Accordingly, the detailed description of the embodiments of the invention provided below is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention.

As shown in fig. 2, a signal receiving and transmitting schematic diagram in the process of RSSI data acquisition is shown, specifically, in the process of RSSI data acquisition, a radio frequency signal is converted into an electric signal through an RX antenna, and the electric signal is amplified by a filter and then subjected to power integration conversion, so as to obtain an RSSI value. The process of the invention is shown in figure 1, and P is obtained after the signal is subjected to power integration _S (symbol power), set P _S The value range is (a, b) by the method of P _S The RSSI is converted after the limit of the value range, so that the effect of more accurate RSSI output value is achieved. The specific process is as follows,

step one: a wireless communication system including a system to be checked is built, the system to be checked is referred to as a "filter gain system", that is, a receiver of the communication system needs to have a function of adjusting a filter gain, and a principle diagram of the system is shown in fig. 2, so that a person skilled in the art can select the filter gain system, the receiver, the transmitter, and the like according to actual situations. According to formula P _RSSI =tp+ag+rg-TL-FL, and after transformation, rg=p is obtained _RSSI TP-ag+tl+fl, TP, AG, TL being known values in a known wireless communication system, FL can be obtained by the following formula:

where d is the communication distance, f is the carrier frequency, P _RSSI Represents the RSSI value, thereby obtaining RG and P _RSSI This can lay a foundation for the subsequent calculation of the true step value of the filter gain system. Then use formula rg=p _RSSI TP-ag+tl+fl, which is to obtain the true step value of the filter gain system, i.e. two differences in RG, since only TL is adjusted, TP, AG, FL can be considered unchanged, Δtl being known. At rg=p _RSSI In the case of TP-AG+TL+FL, the results of the two tests are poor, in some cases,

1. when TL is not changed, there are RG 2-rg1=rss2-RSSI 1, where RSSI2 and RSSI1 are known, RG2 and RG1 represent the gain values of the receiver filters twice before and after, and RSSI2 and RSSI1 are the RSSI values corresponding to RG2 and RG1, respectively, and then the step values RG2-RG1 of RG are known.

2. When TL is changed, RG 2-rg1=rss2-rss1+Δtl, where RSSI2 is known to RSSI1 and Δtl, the step value RG2-RG1 of RG is known.

Since TP, AG and FL are counteracted in the two-way subtraction, the specific values of the three parameters are not needed when only testing the stepping value, which makes the method simple and feasible, and the errors introduced by the three parameters can be eliminated.

Step two: adjusting the gain system of the filter to the lowest-gear gain, and setting P _S The value range is (a, b), and the communication system is startedReceiving and transmitting package, checking receiver P _S And (5) taking a value. In this embodiment, the communication mode adopts wired communication to obtain the real step value of the gain system of the wave device, and the wired system has no FL and AG, so that the final result is more accurate by using the wired system.

Checking the receiver P _S When taking the value, if P _S Near a and within (a, b), a first RSSI value is output. The filter gain is then increased from stage to stage as long as P _S The subsequent RSSI values can be output within (a, b).

If P _S Greater than b, then TL is changed by adding a fixed attenuator to the transmission link to P _S Near a and within (a, b) until the filter gain rises to the highest level.

Step three: and (3) subtracting RSSIs obtained by adjacent gears in the second step, so that the actual step of the filter gain system can be obtained.

Since the free space loss FL calculation formula is in an ideal non-occlusion environment and is different from the real environment, errors are generated (the actual free space loss is changed due to the change of the environment), and therefore, the wired communication is selected in the scheme, and at the moment, no free space loss exists, so that the test precision can be improved.

Step four: and a wireless communication system for acquiring RSSI information is built, and the wireless communication system is started to start to receive and transmit packets. In the receiver, P _S This can be calculated from the following formula:

in the formula->Is the real part, Q is the imaginary part, < >>Number of symbols to participate in the score

P _S The RSSI relationship is shown in fig. 3, which can be converted into the following equation,

step five: checking the receiver P _S The values are processed, as shown in fig. 4, specifically as follows,

if P _S Within (a, b), the RSSI value for that location is output.

If P _S If the value is smaller than a, the gain of the filter is increased, and the step value obtained in the step three can be found by specifically increasing the gear.

If P _S And b, if the value is larger than b, reducing the gain of the filter, and specifically reducing the gear to search the stepping value obtained in the step three.

Thereby can ensure P _S In (a, b), the value is saved.

Step six: the values of the receiver filter gain RG and the receiving antenna gain RAG and the data length K are recorded and saved, as theoretically deduced to be available in FIG. 4, and then are calculated by the formula

Can calculate RSSI value P _RSSI K is the data length, P in the formula _S Is the symbol power.

It is obvious that the present solution is to increase or decrease the filter gain to obtain the desired result, so that a system (AGC) that can manually or automatically adjust the filter gain is equally applicable to the present solution, and if AGC is used, the AGC needs to satisfy the following specific conditions: 1. the feedback of AGC adjustment gain must be controlled by P _S Determining; 2. the target range of AGC adjustment gain is (a, b); 3. the gain of the filter after the AGC adjusts the gain is readable.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that the above-mentioned preferred embodiment should not be construed as limiting the invention, and the scope of the invention should be defined by the appended claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and such modifications and adaptations are intended to be comprehended within the scope of the invention.

Claims

1. A RSSI data sampling method is characterized by comprising the following steps,

step two: adjusting a filter gain system in a communication system to be the lowest-gear gain, and setting symbol power P _S The value range is taken, the communication system is started to start to receive and transmit packets, and the symbol power P of the receiver is checked _S The value is in the set value range, the gain of the filter is controlled to be increased from gear to gear, and the RSSI value is output;

，

P _S and P _RSSI The relationship is as follows:

（1）

k represents the data length, and RAG is the gain of the receiving antenna;

step five: checking receiver symbol power P _S Take the value and process, ensure P _S In the set value range, then save P _S A value;

2. The RSSI data sampling method of claim 1 wherein: in the second step, if P _S To be the minimum value in the value range and in the value range, the first RSSI value is output, and then the filter gain is increased step by step, so long as P _S Continuously outputting the RSSI value within the value range; if P _S If the value is larger than the maximum value in the value range, TL is changed by adding a fixed attenuator on the transmission link, so that P is formed _S Is the minimum value in the value range and is in the value range until the gain of the filter is increased to the highest level.

3. The RSSI data sampling method of claim 1 wherein: in the first step, the communication system is a communication system including a verification system, and the verification system is a filter gain system.

4. A method of sampling RSSI data as claimed in claim 3, wherein: and step one to step three, wherein the transmitting end and the receiving end of the communication system are in wired communication, and the communication system in step four is in wireless communication.

5. The RSSI data sampling method of claim 1 wherein: in the fifth step, the specific process of the treatment is as follows:

if P _S Outputting the RSSI value within the value range;