阅读说明：本技术 一种230MHz频段的频域能量检测方法 (A kind of frequency domain energy detection method of 230MHz frequency range ) 是由 吴玉成 翟莎莎 余盼龙 熊灿云 盛机华 刘巧 喻琼 于 2019-08-22 设计创作，主要内容包括：本发明提供了一种230MHz频段的频域能量检测方法,该方法通过设置合适的频域能量检测的FFT采样速率及采样点数,得到适合工业物联网应用的频率分辨率；检测每个信道内所有FFT采样点的信号功率谱值,找到最大值；将所述信道信号功率谱最大值与预设判决门限进行比较,当所述信道信号功率谱最大值大于所述判决门限时,所述信道被占用,当所述信道信号功率谱最大值小于或等于所述判决门限时,所述信道空闲。可实现频段内的所有信道信息的感知,能够提高检测性能,还具有一定的抗干扰能力。(The present invention provides a kind of frequency domain energy detection method of 230MHz frequency range, this method obtains the frequency resolution for being suitble to industrial Internet of Things application by the way that the FFT sampling rate and sampling number that suitable frequency domain energy detects is arranged；Detect the signal power spectrum of all FFT sampled points in each channel, maximizing；Channel signal power spectrum maximum value is compared with default decision threshold, when channel signal power spectrum maximum value is greater than the decision threshold, the channel is occupied, when channel signal power spectrum maximum value is less than or equal to the decision threshold, the channel idle.The perception that all channel informations in frequency range can be achieved, can be improved detection performance, also have certain anti-interference ability.)

1. a kind of frequency domain energy detection method of 230MHz frequency range characterized by comprising

The FFT sampling rate and sampling number of frequency domain energy detection are set；

The signal power spectrum that all FFT sampled points in each channel are detected using frequency domain energy detection algorithm, finds each letter Maximum value in road；

Power spectrum signal maximum value in selected each channel is compared with default decision threshold, when the signal When power spectral value is greater than the decision threshold, the channel is occupied, when the signal power spectrum is sentenced less than or equal to described Certainly when thresholding, the channel idle.

2. the frequency domain energy detection method of 230MHz frequency range as described in claim 1, which is characterized in that the power channels Frequency range is 223MHz-226MHz and 229MHz-233MHz, and the bin width of each channel is 25kHz, amounts to 280 letters Road.

3. the frequency domain energy detection method of 230MHz frequency range as claimed in claim 2, which is characterized in that first channel is through frequency Spectrum corresponds to baseband signal after moving, and the half of its signal bandwidth is in negative frequency.

4. the frequency domain energy detection method of 230MHz frequency range as claimed in claim 2, which is characterized in that the FFT sampling speed Rate is 20.48MHz, sampling number 4096, every 5 sampled points be a channel.

5. the frequency domain energy detection method of 230MHz frequency range as described in claim 1, which is characterized in that detect in each channel All sampled points signal power spectrum, and the maximum value of gained channel signal power spectral value and the decision threshold are made It is compared.

Technical field

The present invention relates to field of communication technology more particularly to a kind of frequency domain energy detection methods of 230MHz frequency range.

Background technique

With the proposition and development of ubiquitous electric power Internet of Things, power business demand is in iteratively faster, thus to power communication Safety and mobility more stringent requirements are proposed, electric power wireless private network become very important means.To meet the row such as electric power The frequency needs of industry and energy internet, improve frequency usage efficiency and benefit, the Ministry of Industry and Information Technology issue " about adjustment The notice of 223-235MHz frequency range wireless system for transmitting data frequency usage planning ", clear " 223-226MHz and 229-233MHz The broadband system that frequency range (in addition to dedicated frequency) can be polymerize with TDD mode carrier wave ", " is no longer examined at " encouraging common network Model construction " The matters such as 1785-1805MHz frequency range private electric power " and technical requirements, interference protection.In 223-226MHz, 229-233MHz frequency Duan Zhong, the bin width of each primary channel are 25kHz.Based on this, ubiquitous electric power Internet of Things can by discrete carrier polymerize with Frequency spectrum perception technology, realizes the broadband high-speed transfer of discrete narrow band frequency spectrum, and realizes that wide and narrow strip coexists.Therefore, to frequency spectrum sky Not busy correct perception is most important for the operation of power grid.In practical application, can according to ubiquitous electric power Internet of Things to use frequency Corresponding frequency resolution is arranged in the wide requirement of bands of a spectrum, more effectively detection frequency spectrum " cavity ".Herein only to detect primary channel Frequency spectrum idle state for.

Summary of the invention

The purpose of the present invention is to provide a kind of frequency domain energy detection method of 230MHz frequency range, this method is capable of detecting when The occupancy situation of each channel of 280 channels in 223-226MHz and 229-233MHz frequency range.

In order to achieve the above object, the present invention provides a kind of frequency domain energy detection methods of 230MHz frequency range, comprising:

The FFT sampling rate and sampling number of frequency domain energy detection are set；

The signal power spectrum in each channel at all FFT sampled points is detected using frequency domain energy detection algorithm, is found The maximum value of channel signal power spectral value；

The maximum value of the channel signal power spectral value is compared with default decision threshold, when the signal power When spectrum is greater than the decision threshold, the channel is occupied, when the signal power spectrum is less than or equal to the decision gate In limited time, the channel idle.

Optionally, the frequency range of the power channels is 223MHz-226MHz and 229MHz-233MHz, each channel Bin width be 25kHz, amount to 280 channels.

Optionally, first channel corresponds to baseband signal after frequency spectrum shift, and the half of its signal bandwidth is in negative frequency.

Optionally, the FFT sampling rate is 20.48MHz, and sampling number 4096 is one every 5 sampled points and believes Road.

Optionally, the signal power spectrum of all sampled points in each channel is detected, and by all signal power spectrum The maximum be compared with the decision threshold.

In the frequency domain energy detection method of 230MHz frequency range provided by the invention, the FFT that setting frequency domain energy detects is adopted Sample rate and sampling number；The power spectrum signal of all FFT sampled points in each channel is detected using frequency domain energy detection algorithm Value chooses maximum value；The channel signal power spectrum maximum value is compared with default decision threshold, when the signal function When rate spectrum is greater than the decision threshold, the channel is occupied, when the signal power spectrum is less than or equal to the judgement When thresholding, the channel idle.The perception that all frequency point informations in frequency range can be achieved, can be improved detection performance.

Detailed description of the invention

Fig. 1 is channel profile provided in an embodiment of the present invention；

Fig. 2 is the frequency domain energy detection method stream provided in an embodiment of the present invention based on power spectral value at detection channel carrier frequency Cheng Tu；

Fig. 3 is the frequency domain energy detection method stream provided in an embodiment of the present invention based on maximum power spectrum in detection channel Cheng Tu；

Fig. 4 is detection accuracy and Between Signal To Noise Ratio curve graph under different decision thresholds provided in an embodiment of the present invention；

Fig. 5 be it is provided in an embodiment of the present invention based on detection channel carrier frequency at power spectral value frequency domain energy detection method and Traditional frequency domain energy detection method performance comparison；

Fig. 6 is frequency domain energy based on power spectral value at detection channel carrier frequency provided in an embodiment of the present invention when having an interference signal Quantity measuring method and based on detection channel in maximum power spectrum frequency domain energy detection method performance comparison.

Frequency domain energy based on power spectral value at detection channel carrier frequency when Fig. 7 is state no interference signal provided in an embodiment of the present invention Quantity measuring method and based on detection channel in maximum power spectrum frequency domain energy detection method performance comparison.

Specific embodiment

A specific embodiment of the invention is described in more detail below in conjunction with schematic diagram.According to following description, Advantages and features of the invention will become apparent from.It should be noted that attached drawing is all made of very simplified form and using non-accurate Ratio, only for the purpose of facilitating and clarifying the purpose of the embodiments of the invention.

Present embodiments provide the frequency domain energy detection method of 230MHz frequency range, comprising:

Step S1: the FFT sampling rate and sampling number that setting frequency domain energy detects；But the frequency used due to power industry Point is distributed in 223-226MHz and 229-233MHz frequency range, and the bandwidth of each minimum channel is 25kHz.To disposably detect The spectral range of the occupancy situation of all frequency points, detection is at least greater than 10MHz.Thus the FFT's that setting frequency domain energy detects Sampling rate is 20.48MHz, and FFT sampling number is 4096, then the band width of 5 sampled points is 25kHz, i.e., every five A sampled point is a channel.First channel corresponds to baseband signal after frequency spectrum shift, therefore the half of its signal bandwidth is negative Frequency, therefore the width 12.5Khz of first frequency point, specific frequency point distribution map are as shown in Figure 1.

Step S2: as shown in Fig. 2, detecting the letter of FFT sampled point at each channel carrier frequency using frequency domain energy detection algorithm Power frequency spectrum value.

Step S3: the signal power spectrum is compared with default decision threshold, when the signal power spectrum is big When the decision threshold, the channel is occupied, when the signal power spectrum is less than or equal to the decision threshold, institute State channel idle.

Further, as shown in Figure 3, it is contemplated that there are hostile interference signals, in adverse party tranmitting frequency not in each channel When narrow-band interference signal at 25kHz carrier frequency, frequency point signal power spectrum at carrier frequency is only detected, can not just detect hostile interference Signal.Further, the channel signal function that detects the signal power spectrum of all sampled points in each channel, and will test The maximum value of rate spectrum is compared with the decision threshold, adjudicates frequency point occupancy situation with this value, channel can be improved Detection accuracy reduces the influence of interference signal to a certain degree.

The key of the frequency domain energy detection method performance of the 230MHz frequency range is the selection of decision threshold, decision threshold Excessively high to will lead to false dismissal probability increase, decision threshold is too low, and false-alarm probability is caused to increase.Decision threshold it is excessively high or it is too low all Will lead to spectrum cognitive network efficiently can not realize normal communication using idle frequency spectrum.It is verifying decision threshold for detection performance Influence, mainly research decision threshold and detection accuracy between relationship, give difference using MATLAB emulation tool and sentence The certainly graph of relation that detection accuracy (false-alarm probability and detection probability) changes with signal-to-noise ratio under thresholding.

When channel state no interference signal, it is assumed that occupy the signal of frequency spectrum resource carrier frequency be 0kHz, 25kHz, 100kHz, 200kHz, 6000kHz, when remaining channel idle.Noise power spectrum density is the white Gaussian noise of -100dBm, Decision threshold 1 is 7 times of noise mean values, and decision threshold 2 is 4 times of noise mean values, and decision threshold 3 is 2 times of noise mean values, repeats to emulate Number is 100 times.Fig. 4 is that energy value is perceived at the detection carrier frequency proposed.Figure 4, it is seen that reducing default Although detection probability can be improved to a certain extent, reduce false dismissal probability for decision threshold, false-alarm probability promotion will lead to, Cause a large amount of idle of frequency spectrum resource.Though it is general to will cause detection correspondingly, false-alarm probability can be reduced by improving default decision threshold Rate reduces, and false dismissal probability increases, and multiple equipment mistake is led to problems such as to access same frequency range, cause communication contention aware in network.In In practical application, spectrum cognitive algorithm should be able to real-time change according to channel circumstance and specific communication technology index need It asks, it is appropriate to choose optimal judgement thresholding, to realize the optimal performance of spectrum cognitive.

It is frequency domain energy detection algorithm (calling method 1 in the following text) and tradition based on power spectral value at detection channel carrier frequency in Fig. 5 Frequency domain energy detection method is when false-alarm probability is identical, the comparison diagram of detection performance.From figure 5 it can be seen that based on detection letter The frequency domain energy detection algorithm of road carrier frequency has the performance boost of 2dB compared with traditional frequency domain energy detection algorithm.This is because in low letter Make an uproar than when, signal can more accurately be detected by detecting the frequency domain energy value at carrier frequency, and signal energy is averaged point after averaging It is fitted in entire channel.To the certain false-alarm probability of holding, decision threshold raising will cause, and signal energy is averaged decrease Afterwards, in low signal-to-noise ratio, signal energy may be lower than decision threshold, to reduce detection probability after being evenly distributed to channel.

Fig. 6 is there are when interference signal, and the frequency domain energy detection method based on maximum power spectrum in detection channel (is called in the following text Method 2) with based on detection channel carrier frequency power spectral value frequency domain energy detection algorithm performance comparison figure.At this point, occupying frequency spectrum The signal frequency of the channel of resource is 5kHz, 20kHz, 100kHz, 200kHz, 6000kHz, remaining channel idle.Two kinds of frequency spectrum The decision threshold of improved method is identical, is 5 times of noise mean values.As can be seen from Figure 6: 1 detection performance of method is far below method 2 Detection performance.But the false-alarm probability of a little higher than method 1 of the false-alarm probability of method 2, this is because in low signal-to-noise ratio, due to making an uproar The uncertainty of sound, it is understood that there may be the noise in channel at certain FFT sampled points is greater than decision threshold, to cause false-alarm probability Increase.The method that compares 1, method 2 can more accurately detect interference signal when there is interference signal, have certain resist Interference performance.

When Fig. 7 is state no interference signal, the frequency domain energy detection method (side of calling in the following text based on maximum power spectrum in detection channel Method 2) with based on detection channel carrier frequency power spectral value frequency domain energy detection algorithm performance comparison figure.It can be seen from the figure that When signal is at the carrier frequency of channel, the detection performance and 1 performance of method of method 2 are close, and only the false-alarm probability of method 2 can be slightly Greatly.But also in the range of tolerable.While i.e. method 2 is had with 1 identical detection performance of method, and there is certain resist Interference performance.In practical applications, the spectrum cognitive algorithm based on channel signal power spectrum maximum value should be according to channel circumstance Real-time change and specific communication technology index demand, it is appropriate to choose optimal judgement thresholding, to realize spectrum cognitive most Dominance energy.

To sum up, in the frequency domain energy detection method of 230MHz frequency range provided in an embodiment of the present invention, frequency domain energy is utilized Detection algorithm detects the signal power spectrum of all FFT sampled points in each channel, chooses maximum value；By the channel signal Power spectrum maximum value is compared with default decision threshold, described when the signal power spectrum is greater than the decision threshold Channel is occupied, when the signal power spectrum is less than or equal to the decision threshold, the channel idle.Frequency range can be achieved The perception of interior all frequency point informations can be improved detection performance, also have certain anti-interference ability.

The above is only a preferred embodiment of the present invention, does not play the role of any restrictions to the present invention.Belonging to any Those skilled in the art, in the range of not departing from technical solution of the present invention, to the invention discloses technical solution and Technology contents make the variation such as any type of equivalent replacement or modification, belong to the content without departing from technical solution of the present invention, still Within belonging to the scope of protection of the present invention.