CN203072168U - Sensing node - Google Patents

Abstract

The utility model provides a sensing node, comprising a data acquisition module used for acquiring a signal, a Zigbee baseband processing module used for processing data outputted by the data acquisition module, and a radio frequency module used for receiving a signal outputted by the Zigbee baseband processing module; wherein the radio frequency module comprises at least two antenna units, and the Zigbee baseband processing module comprises a demultiplexer used for partitioning data processed by the Zigbee baseband processing module into a plurality of data links. The sensing node of the utility model can be applied to an IOT (Internet Of Things) based on Zigbee technology, and can transmit the acquired data through a plurality of channels, thereby greatly raising reliability and coverage area of data transmission, raising a data transmission rate, and realizing working function of the sensing node; in addition, the sensing node of the utility model can greatly raise data transmission capability, anti-interference capability and data transmission coverage area of the sensing node in the same wireless broadcasting environment, thereby raising reliability and stability of the IOT of the sensing node.

Description

A kind of sensing node

Technical field

The utility model belongs to the Internet of Things field, is specifically related to a kind of sensing node that is applied to Internet of Things.

Background technology

Zigbee (short distance, lower powered wireless communication technology) be a kind of emerging closely, low complex degree, low-power consumption, low message transmission rate, radio network technique cheaply, be widely used in the Internet of Things field according to its characteristics, become network struction mode main in the Internet of Things, can be between thousands of small sensing nodes coordinating communication mutually, owing to can intercom mutually between sensing node, therefore can form many transmission paths, ensure that data can be transferred to data center.

Existing Zigbee technology adopts the mode of single channel output more, again by radio-frequency module and amplifier carry out the transmission of signal and simply control circuit form.Network at this sensing node structure, communication between the sensing node is subject to the data transmission capabilities of sensing node, can cause that seriously the losing of under wireless multi-path environment data, signal cover sharply reduce, and the appearance of situation such as data throughout is lower, if strengthen the transmitting power of sensing node, then can cause the huge use of energy, and also be limited in the improvement of sensing node aspect of performance.

The utility model content

In order to solve the problems of the technologies described above, the utility model provides a kind of sensing node, the mode of this sensing node by many of many data emission circuit solved data and lost phenomenon in transmission course, realized the raising of sensing node service behaviour, to achieve these goals, the utility model is by the following technical solutions:

A kind of sensing node comprises the Zigbee baseband processing module of handling for the data acquisition module of gathering signal, to described data acquisition module output data and the radio-frequency module that receives described Zigbee baseband processing module output signal; Described radio-frequency module comprises at least two antenna elements, and described Zigbee baseband processing module comprises the demultiplexer that described Zigbee baseband processing module deal with data is divided into a plurality of data link.

Further, described Zigbee baseband processing module is SOC.

Further, described Zigbee baseband processing module comprises frequency multiplier, encoder and the modulator that connects successively, and described demultiplexer is connected with the output of described modulator.

Further, described Zigbee baseband processing module also comprises synchronous FIFO module, and described synchronous FIFO module connects the output of described demultiplexer.

Further, described radio-frequency module comprises D/A converter, and described D/A converter is identical with the number of described antenna element.

Further, described radio-frequency module also comprises power amplifier, and described D/A converter is handled the back data and export to described antenna element after described power amplifier is amplified.

Further, described power amplifier is identical with the number of described antenna element.

Further, described data acquisition module comprises one or more transducer and the A/D converter that is connected with described transducer.

Further, described Zigbee baseband processing module also comprises the power distributing unit that is connected with described data link.

Further, described Zigbee baseband processing module also comprises the channel estimation unit that is connected with described power distributing unit.

Sensing node of the present utility model can be applied to the Internet of Things network based on the Zigbee technology, the data of gathering can be sent by a plurality of channels, guaranteed reliability of data transmission, realize the function of sensing node work, data transmission capabilities, antijamming capability and the transfer of data coverage of raising sensing node that can be very big under same wireless propagation environment, and then improved the reliability and stability of the Internet of Things network that comprises this sensing node.

Description of drawings

Fig. 1 is the module map of a kind of sensing node execution mode 1 of the utility model;

Fig. 2 is the module map of a kind of sensing node execution mode 2 of the utility model;

Fig. 3 is the module map of a kind of sensing node execution mode 3 of the utility model;

Fig. 4 is execution mode multichannel power allocation scheme figure shown in Figure 3.

Embodiment

Below in conjunction with accompanying drawing the utility model is described further.

Referring to Fig. 1, be depicted as the module map of a kind of sensing node execution mode 1 of the utility model, this sensing node comprises data acquisition module, Zigbee baseband processing module and radio-frequency module.Wherein, data acquisition module is used for Information Monitoring and exports corresponding digital signal, and this information comprises the state information of acquisition target, for example temperature, brightness, pressure etc.The Zigbee baseband processing module is connected with the output of data acquisition module, and it comprises frequency multiplier, encoder, modulator, demultiplexer, data link and the transfer of data synchronous FIFO module that connects successively; Wherein, frequency multiplier mainly is to export spread-spectrum signal after utilizing the digital signal spread-spectrum of DS sequence code to the output of data acquisition module that digital circuit produces in the frequency multiplier; Encoder is differential encoder, and after differential encoder received signal behind the frequency multiplier spread spectrum, the signal that obtains after modulator is to differential coding was modulated and obtained modulation signal; Signal after demultiplexer is finished modulation carries out multichannel and decomposes, and the signal after decomposing is formed data link respectively output to synchronous FIFO module, and synchronous FIFO module is exported to radio-frequency module with data synchronously.Radio-frequency module comprises D/A converter, power amplifier and the antenna element with data path number same number, D/A converter converts the multi-path digital signal of fifo module output analog signal to and exports to power amplifier, amplifies through power amplifier and launches by antenna element.

Demultiplexer can be decomposed into digital signal two-way, three tunnel, four tunnel or multichannel more, and each road can be identical digital signal, also can be the packet that the part digital signal forms, and specifically the size of data that forms according to the digital signal of transmission is determined.

Referring to Fig. 2, be depicted as the module map of a kind of sensing node execution mode 2 of the utility model, this sensing node is compared with execution mode 1, the main distinction has been to comprise the execution mode of data acquisition module, wherein data acquisition module has comprised transducer and A/D converting unit, transducer can be one or a kind of, also can be a plurality of or multiple, and the signal of transducer collection flows to the Zigbee baseband processing module after the A/D converting unit converts digital signal to.

Referring to Fig. 3, be depicted as the module map of a kind of sensing node execution mode 3 of the utility model, this sensing node is compared with execution mode 2, the main distinction is that the Zigbee baseband processing module has further comprised channel estimation unit and power distributing unit, when data are exported, after carrying out channel estimating earlier, carrying out channel according to the result parameter that obtains behind the channel estimating selects, select the channel of transmission performance optimum, recycling power division module is distributed in that the average power size of data link module adjustment by coding and modulation system or bit again carried out power optimization to the binary bits sign indicating number of modulation.Concrete, channel estimation unit utilize modulation signal itself intrinsic, come channel is calculated with irrelevant some features of concrete beared information bit, according to result of calculation, the higher channel of signal to noise ratio is carried out the more power distribution.Determine the signal to noise ratio of channel as the normal RSSI of use in Zigbee (receiving the signal strength signal intensity indication) algorithm, RSSI is the parameter of utilizing software and combination of hardware method to test each channel, one by one the parameter that every channel receives is carried out computational analysis by software, can obtain the signal to noise ratio of different channels.Power distributing unit at first obtains the signal to noise ratio of each channel by channel estimation module, be basis with signal to noise ratio and gross energy, the average power size of the coded system of signal in each channel and modulation type or each bit is selected and adjusted, finish each signal power size is distributed.Wherein, the power division mode is preferentially used the self adaptation principle of pouring water.Can realize the rationalization that the data power resource is distributed by channel estimating and power division, improve the efficiency of transmission of overall communication system.

In the present embodiment, multichannel reception signal is

$y=\underset{k=1}{\overset{m}{\mathrm{\Σ}}}{h}_k{p}_k{x}_k+n_i;$

Wherein, k is the label of transmitting antenna, and m is the number of transmitting antenna, and h is channel, and x is the signal of transmitting antenna, n _iBe noise.

The multichannel system throughput can be expressed as

$f\left(p_i\right)=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{\log }_2(1+\frac{{\left|\right|S_i\left|\right|}^2{{\mathrm{\λ}}_i}^2{p}_i}{{\mathrm{\σ}}^2});$

Wherein, σ ²Be the white noise variable, || S _i|| be each channel signal receiving intensity, λ _iBe each channel characteristic value.. traditional pour water power distribution algorithm or average power algorithm only support the single channel power division can not realize that maybe best resource optimizes performance, and present embodiment is considered total allocation power, and its method of salary distribution at each channel is as follows:

$g_i\left(p_i\right)=p_c-\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{p}_i-\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{{\mathrm{\λ}}_i}^{-1},i=\mathrm{1,2}\·\·\·m;$

Here gross power Pc=tr (QQ ^H), Q ⁱIt is the burst matrix of each receive channel.

Be simplified embodiment and raising enforceability, corrected output distributes formula to be:

$p_1+\frac{1}{{\mathrm{\&lambda;}}_1}={\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HSA00000860677400021.png"\; state="\{\{state\}\}">p</figure-callout>}}_2+\frac{1}{{\mathrm{\&lambda;}}_2}=p_m+\frac{1}{{\mathrm{\&lambda;}}_m}\&CenterDot;\&CenterDot;\&CenterDot;=\frac{p_c}{m}=u;$

Wherein, p _c={ p ₁, p ₂... p _mBe the distribution power of each channel, wherein u is the horizontal constant of pouring water, and determines according to system power.

The multichannel power allocation scheme of present embodiment as shown in Figure 4.

The Zigbee baseband processing module can adopt the SOC SOC (system on a chip), also can adopt MCU processing unit etc.

The above only is preferred embodiment of the present utility model; be not so limit claim of the present utility model; every equivalent structure or equivalent flow process conversion that utilizes the utility model specification and accompanying drawing content to do; or directly or indirectly be used in other relevant technical fields, all in like manner be included in the scope of patent protection of the present utility model.

Claims (10)

1. sensing node, it is characterized in that, comprise the Zigbee baseband processing module of handling for the data acquisition module of gathering signal, to described data acquisition module output data and the radio-frequency module that receives described Zigbee baseband processing module output signal; Described radio-frequency module comprises at least two antenna elements, and described Zigbee baseband processing module comprises the demultiplexer that described Zigbee baseband processing module deal with data is divided into a plurality of data link.

2. sensing node according to claim 1 is characterized in that, described Zigbee baseband processing module is SOC.

3. sensing node according to claim 1 is characterized in that, described Zigbee baseband processing module comprises frequency multiplier, encoder and the modulator that connects successively, and described demultiplexer is connected with the output of described modulator.

4. sensing node according to claim 3 is characterized in that, described Zigbee baseband processing module also comprises synchronous FIFO module, and described synchronous FIFO module connects the output of described demultiplexer.

5. sensing node according to claim 1 is characterized in that, described radio-frequency module comprises D/A converter, and described D/A converter is identical with the number of described antenna element.

6. sensing node according to claim 5 is characterized in that, described radio-frequency module also comprises power amplifier, and described D/A converter is handled the back data and export to described antenna element after described power amplifier is amplified.

7. sensing node according to claim 6 is characterized in that, described power amplifier is identical with the number of described antenna element.

8. sensing node according to claim 7 is characterized in that, described data acquisition module comprises one or more transducer and the A/D converter that is connected with described transducer.

9. sensing node according to claim 1 is characterized in that, described Zigbee baseband processing module also comprises the power distributing unit that is connected with described data link.

10. according to claim 1 or 9 described sensing nodes, it is characterized in that described Zigbee baseband processing module also comprises the channel estimation unit that is connected with described power distributing unit.

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