CN100573665C - Energy detection device and method - Google Patents

Abstract

The invention provides an energy detection device and method. The device and the method for energy detection of the invention can obtain a new energy detection value by subtracting a previous sampling average value and a sampling absolute value from the currently output energy detection value. The device and the method for energy detection of the invention do not need to use a memory, save the cost and provide real-time energy detection without time delay.

Description

Device and method for energy detection

technical field

The present invention relates to a device and method for energy detection or, in particular, relates to a device and method for energy detection without time delay.

Background technique

Digital signals play an important role in the data processing of various modern multimedia, and one of the applications is digital audio which is a one-dimensional signal. The combination of sound signal and digital signal processing is an indispensable foundation in the field of communication.

For sound signal data, the amount of data is usually large and continuous and contains many false noise signals and interferences. In order to effectively retrieve the correct signal, it is necessary to judge whether the signal is correct or not. Traditionally, it is determined whether to acquire the signal by detecting the strength of the signal energy. Simply put, when the energy detected at a certain time point is higher than a preset energy threshold, it is determined that the signal at the next time point can be captured and utilized; otherwise, if it is lower than this If the energy threshold is lower, the signal at the next time point is determined to be a noise signal and will not be captured. The detection of energy is to use the initial input signal to obtain the input analog signal (analog signal) through the sampler, go through steps such as discretization and conversion into digital signal (digital signal), and then calculate a certain time with multiple samples obtained The average energy value of the interval is used as the basis for identifying the energy level during energy detection. The following is a brief description of conventional energy detection methods.

1A, 1B, and 1C respectively illustrate a schematic diagram of sampling an input signal sample, a schematic diagram of an output waveform of an energy detection result, and a schematic diagram of an output signal sample obtained or processed according to the energy detection result in a conventional energy detection method.

Please refer to FIG. 1A , FIG. 1B , and FIG. 1C respectively. FIG. 1A is a schematic diagram of input signal sample sampling, which sequentially samples a plurality of input signal sample values and takes them as absolute values. In the general energy detection method, in order to estimate and detect the energy value effectively and appropriately, a detection window (window detetion) is defined to determine the calculation standard during energy detection, that is, to define the sampling time length and the number of samples As the basis for energy detection. For example, the detection window shown in FIG. 1A is 8 samples long, and FIG. 1A shows a schematic diagram of sample sampling in the nth time block and the n+1th time block according to the size of the detection window.

Figure 1B is a schematic diagram of the output waveform of the energy detection result. The energy detection is carried out by using a memory to store the input signal sampling data in a time block, using these data to obtain the energy value through calculation, and then according to this calculation. The obtained energy value is used to decide whether to process or capture and output the sampled data stored in the internal memory. Referring again to FIG. 1C , the output schematic diagram of capturing signal samples according to the energy detection result. It can be clearly seen from Figures 1A to 1C that during the process, at the nth time block, the sample sampling operation is still carried out sequentially (see the nth time block in Figure 1A), but the output of the energy detection result And the samples output according to the energy detection results are all values at the n-1th time block. In short, the energy detection of any time block is based on the value stored in the memory in the previous time block.

The current energy detection is based on the samples collected in the previous time, which delays the energy detection time, cannot effectively reflect the real-time detection of energy, and has to bear the cost of the memory used to store the data. Therefore, the lack of energy detection includes energy detection time lag and memory cost.

2A, 2B, and 2C respectively show a schematic diagram of sampling input signal samples in another conventional energy detection method, a schematic diagram of output waveforms of energy detection results, and a schematic diagram of capturing or processing signal samples according to energy detection results. Output schematic. Please refer to FIG. 2A , FIG. 2B , and FIG. 2C respectively. FIG. 2A is the same as the aforementioned FIG. 1A , and is also a schematic diagram of sampling input signal samples for energy detection, which is formed by sequentially sampling a plurality of input signal sample values and taking them as absolute values.

Figure 2B is a schematic diagram of the output waveform of the energy detection result. Unlike the previous method that uses memory, this method does not store the input signal sampling data, but uses a hardware similar to digital signal processing for accumulation. and calculation to obtain the energy value of the last time block, and decide whether to process or retrieve the sampling data currently being sampled according to the obtained energy value. Finally, it can be seen from FIGS. 2A to 2C that although the use of this hardware allows the sampling data to be output immediately after input, that is, the value of the nth time block is immediately output (see the output of FIG. 1C Schematic diagram), but still use the energy detection result of the n-1th time block. Therefore, the energy detection method causes a time delay between the energy detection result and the output sampling data.

To sum up, the traditional energy detection method, on the one hand, must add the cost of the memory used to store the input data, and on the other hand, it cannot dynamically calculate and output in real time when detecting energy, resulting in output Due to the shortcoming of time delay, it cannot meet the fast and accurate energy detection requirements of current energy detection applications.

Therefore, the present invention proposes a device and method for energy detection, which not only saves the cost of conventional memory but also provides energy detection without time delay and has real-time dynamic energy detection.

Contents of the invention

The purpose of the present invention is to provide a device for energy detection, which can be used for energy detection calculations, without the need for additional memory required by traditional energy detection devices to reduce costs, and can perform Energy detection without time delay.

Yet another object of the present invention is to provide a method for energy detection, which uses an output energy detection value minus a previous sampled average value plus a sampled absolute value to obtain Obtaining a new energy detection value can effectively solve the lack of time delay caused by the traditional energy detection method that can only use the previous old value.

Another object of the present invention is to provide a method of energy detection, the method of energy detection utilizes an output energy detection value minus a previous sampling average and adding a sampling absolute value to obtain the period T ₁ The energy detection value of the next cycle of the clock signal. In addition, the clock signal of another cycle _T2 is used to calculate the sampling average value to provide this method, so it can also solve the traditional energy detection method. Latency, and the calculation of the sampled average is more representative.

The present invention proposes an energy detection device, which includes an absolute value acquirer, a first adder, a first flip-flop, a second adder and a calculation unit. The absolute value getter receives a plurality of sampled values in sequence, and outputs the absolute value of these inputted sampled values. The first adder is coupled to the absolute value obtainer, which adds a first intermediate calculation value to the output of the absolute value obtainer and outputs it. The first flip-flop is coupled to the first adder, which outputs the output of the first adder according to a first clock signal to obtain an energy detection value, wherein the period of the first clock signal is T ₁ . The second adder is coupled to the first flip-flop and the first adder, and subtracts a sampled average value from the energy detection value to output a first intermediate calculated value. The calculation unit is coupled to the absolute value getter and the second adder, and it calculates the average value of the outputs of all the absolute value getters in any cycle of the second clock signal according to the second clock signal, so as to Outputting the aforementioned sampled average value, wherein the period of the second clock signal is T ₂ , and T ₂ =T ₁ *k, where k is a natural number.

The present invention proposes a method for energy detection. This method firstly inputs a sampling value P(t) sequentially according to a clock signal. The period of the pulse signal is T. Then, the input sampling value P(t ) after taking the absolute value, output a sampled absolute value |P(t)|, at this time, calculate the sum of all the sampled absolute values Sum(|P(t-i*T)| ) and divided by k, output a previous sampling average value, where k is a natural number, i is 1 to k, and finally, an energy detection value is subtracted from the previous sampling average value and the sampling absolute value |P(t )| to obtain the energy detection value of the next cycle of the clock signal.

The present invention proposes another method for energy detection. This method first reads in a plurality of sampled values sequentially, and after taking the absolute values of these input sampled values, outputs a plurality of sampled absolute values. At this time, according to a first clock signal, after subtracting a sampling average value from an energy detection value and adding the current aforesaid sampling absolute value to obtain the energy detection value of the next cycle of the first clock signal, the first clock signal The period is T ₁ , and at the same time, according to a second clock signal, the sum of the absolute values of all these samples in the previous cycle of the current second clock signal is calculated and averaged, so as to output the above-mentioned sample average value. The period of the second clock signal is T ₂ , and T ₂ =T ₁ *k, where k is a natural number.

To sum up, the energy detection device and method of the present invention can obtain a new energy detection value by subtracting a previous sampling average value from the output energy detection value and adding a sampling absolute value . The energy detection device and method of the present invention not only saves cost by not using memory, but also provides energy detection with real-time dynamics and no time delay.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

FIG. 1A is a schematic diagram of input signal sample sampling in a traditional energy detection method;

FIG. 1B is a schematic diagram of an output waveform of an energy detection result of a traditional energy detection method;

FIG. 1C is a schematic diagram illustrating an output of a traditional energy detection method for capturing or processing signal samples according to the energy detection result;

FIG. 2A is a schematic diagram of input signal sample sampling in another traditional energy detection method;

FIG. 2B is a schematic diagram of an output waveform of an energy detection result of another traditional energy detection method;

FIG. 2C is a schematic diagram illustrating an output of another traditional energy detection method for capturing or processing signal samples according to the energy detection result;

3A and FIG. 3B are circuit block diagrams, respectively depicting an energy detection device according to an embodiment of the present invention;

FIG. 4 is a flow block diagram illustrating an energy detection method of the present invention;

FIG. 5 is a flow block diagram illustrating another energy detection method according to the present invention.

Detailed ways

3A and 3B are circuit block diagrams, respectively depicting an energy detection device and a calculation unit in the device according to an embodiment of the present invention, which will be described in detail later. Referring to FIG. 3A , the energy detection device 300 includes an absolute value valuer 301 , a first adder 302 , a first flip-flop 303 , a second adder 304 and a calculation unit 305 .

First, the absolute value acquirer 301 in the energy detection device 300 will sequentially receive a plurality of sampled values, and after taking the absolute value of these sampled values, obtain the sampled absolute value, and then output the sampled absolute value to a The absolute value acquirer 301 is electrically connected to the first adder 302 . The first adder 302 is used to receive the absolute value of the sample and add the output of the second adder 304, and the output of the second adder 304 is the output calculated by subtracting the output of the first flip-flop 303 from the calculation unit 305 , the first adder 302 outputs the summed result to the first flip-flop 303 . Finally, the first flip-flop 303 outputs the output of the first adder 302 according to the clock signal of a cycle T ₁ , and the output value is the energy detection value of the energy detection device 300 .

Wherein, the second adder is used to subtract the energy detection value output by the first flip-flop 303 from the sampling average value calculated by the calculation unit 305, and then feed back the obtained value to first adder 302 . The value given back to the first adder has already subtracted the sample average value of the previous time from the energy detection value output by the current device 300, and this value is passed to the first adder and then added to the absolute value of the input sample, In this way, the next cycle energy detection value of the energy detection device 300 can be provided. Therefore, the energy detection value output by the device 300 is not only immediately included in the absolute value of the new sample, the current output energy detection value, and the value taking into account the average value of the previous sample, thus providing a real-time output without time delay. Periodic new energy detection value.

Next, the calculation unit 305 for calculating the sampling average value in the above-mentioned embodiment of the present invention will be described in detail. FIG. 3B is a circuit block diagram illustrating the calculation unit 305 of the embodiment of the present invention shown in FIG. 3A . The calculation unit 305 includes a third adder 306 , a multiplexer 307 , a second flip-flop 308 , a third flip-flop 309 , and a divider 310 .

In FIG. 3B , the calculation unit 305 is electrically connected to the absolute value acquirer 301 (see FIG. 3A ) to sequentially receive a plurality of sampled absolute values. Afterwards, the third adder 306 outputs the sampled absolute value to a multiplexer 307 electrically connected thereto. The multiplexer 307 is used to select one of the absolute sampled value of the third adder 306 and a zero value to output according to the clock signal of a period _T2 , and its function is to output when the period _T2 ends. The value will be reset to recalculate the value for the next cycle. The multiplexer 307 is then connected to a second flip-flop 308 . Wherein, T ₂ =T ₁ *k, k is a natural number.

In the period _T2 of the clock signal, after the clock pulse (clock) of each period _T1 is triggered, the second flip-flop 308 sends the value at its input terminal to the third adder 306, and the third adder 306 sends the new The absolute value of the sample plus the value sent by the second flip-flop 308, and then the summed value is sent to the second flip-flop 308 through the multiplexer 307, so the values are sequentially accumulated in the second flip-flop 308 in. When the period T ₂ ends, the second flip-flop 308 will output an accumulated value, which is temporarily stored by the third flip-flop 309 , and at the same time, the multiplexer 307 takes in a zero value (reset, the value is reset to zero).

Next, the one electrically connected to the second flip-flop 308 outputs the above-mentioned accumulated value to a divider 310 electrically connected thereto to perform division of the accumulated value, for example, the division value is a natural number k. It should be noted that the third flip-flop 309 is also controlled by the clock of period _T2 .

In an embodiment of the present invention, the above-mentioned divider 310 may be a shift register, such as a 6-bit shift register, for providing a division value 64 .

Finally, the arithmetic unit 305 outputs the value obtained by dividing the accumulated value in the divider 310 , and this value is the sampled average value output to the second adder 304 in FIG. 3A .

FIG. 4 is a flow block diagram of an energy detection method according to the present invention. Please refer to Figure 4. First, in steps S401 and S402 respectively, a sampled value P(t) is sequentially read according to a clock signal with a cycle T, and after the sampled value P(t) is taken as an absolute value, a sampled absolute value is obtained |P(t)|, and output to the next step. In step S403, a previous sampling average value is calculated. The calculation method is to accumulate the absolute values of all samples from time t-k*T to time t-T to obtain a sum value Sum(|P(t-i*T)|), and then divide by k to obtain the desired average value of previous samples . And k is a natural number, and i is 1 to k. Finally, in step S404, an energy detection value is subtracted from the previous sampling average obtained in step S403, and the sampling absolute value |P(t)| is added to obtain the next period of the clock signal energy detection value.

FIG. 5 is a flow block diagram of another energy detection method according to the present invention. Please refer to Figure 5. Firstly, in step S501 and step S502 respectively, a plurality of sampled values are sequentially read in, and the inputted multiple sampled values are taken into absolute values and then output. Next, step S503 calculates the energy detection value of the next cycle according to the clock signal of one cycle _T1 . The calculation in this part is to subtract a sampling average value from an energy detection value and add the current sampling absolute value to obtain the desired energy detection value of the next period of the _T1 clock signal.

At this time, the energy detection value of the next cycle calculated in step S503 will be output for calculation and use in step S504; on the other hand, it will be output to step S505 to complete the result of an energy detection method according to the present invention. In step S504, based on the clock signal of another cycle _T2 , the sum of all the absolute values of the multiple samples in the previous cycle of the current clock signal is calculated and averaged to output a sample average value, as described above The description is provided to step S503. It should be noted that in the energy detection method of this invention, T ₂ =T ₁ *k, k is a natural number.

To sum up, the energy detection device and method of the present invention are used to calculate the energy detection value, so no additional memory is needed to reduce the cost, and energy detection without time delay can be performed.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, this The scope of protection of the invention shall be defined by the scope of the appended patent application.

Claims (5)

1. A device for energy detection, comprising: An absolute value obtainer, which receives a plurality of sampled values in sequence, and outputs the absolute value of the inputted sampled values; a first adder, coupled to the absolute value obtainer, for adding a first intermediate calculation value to the current output of the absolute value obtainer; a first flip-flop coupled to the first adder, for outputting the output of the first adder according to a first clock signal to obtain an energy detection value, the first clock signal The period is T ₁ ; A second adder, coupled to the first flip-flop and the first adder, is used to subtract a sampling average value from the energy detection value, and output the first intermediate calculated value to the first adder ;as well as An arithmetic unit, coupled to the absolute value getter and the second adder, is used to calculate all the absolute value values in any period of the second clock signal according to a second clock signal The average value of the output of the device is used to output the sampled average value to the second adder, the period of the second clock signal is T ₂ , and T ₂ =T ₁ *k, k is a natural number. 2. The energy detection device as claimed in claim 1, wherein the calculation unit comprises: A third adder, coupled to the absolute value accessor, for adding a second intermediate calculation value to the output of the absolute value accessor to output it; a multiplexer, coupled to the third adder, for alternatively outputting the output of the third adder and a zero value according to the second clock signal; a second flip-flop coupled to the multiplexer, for outputting the output of the multiplexer according to the first clock signal to obtain a third intermediate calculation value; a third flip-flop coupled to the second flip-flop for outputting the third intermediate calculation value according to the second clock signal to obtain a sum value; and A divider, coupled to the third flip-flop, is used for dividing the sum by k to output the sampled average value. 3. The energy detection device as claimed in claim 1, wherein the divider of the calculation unit is a shift register. 4. A method for energy detection, comprising: According to a clock signal, a sampling value P(t) is sequentially input, and the period of the clock signal is T; After taking the absolute value of the input sampling value P(t), output a sampling absolute value |P(t)|; Calculate the sum Sum(|P(t-i*T)|) of the absolute values of all these samples from time t-k*T to time t-T and divide by k to output a previous sample average value, where k is a natural number and i is 1 to k; and After subtracting the previous sampling average value from an energy detection value and adding the sampling absolute value |P(t)|, the energy detection value of the next cycle of the clock signal is obtained. 5. A method for energy detection, comprising: Sequentially read in a plurality of sampling values, and after taking the absolute values of the input sampling values, output a plurality of sampling absolute values; According to a first clock signal, after subtracting a sampling average value from an energy detection value and adding the current sampling absolute value, the energy detection value of the next period of the first clock signal is obtained, The period of the first clock signal is T ₁ ; and According to a second clock signal, calculate and average the sum of the absolute values of all the samples in the last cycle of the current second clock signal to output the sample average value, the second clock signal The period is T ₂ , and T ₂ =T ₁ *k, where k is a natural number.

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