Packet detection method and communication device

Abstract

A packet detection method and a communication device, the packet detection method comprising the following steps: receiving a wireless communication signal; calculating a delay correlation function of the wireless communication signal; calculating a delay correlation output value and a threshold value according to the delay correlation function; and determining whether the wireless communication signal satisfies a feature of a wireless network packet according to the delay correlation output value and the threshold value.

Description

Technical Field

[0001] The present disclosure relates to a packet detection method and a communication device, and in particular to a delay-correlated packet detection method and a communication device. Background Art

[0002] The most common packet detection in current communication systems is to use the periodic characteristics of short training sequences. When the received signal's power, matching filter output value, and delay correlation meet certain conditions, the receiver determines that there is a packet being sent or received in the air.

[0003] If packet detection mistakenly identifies interference or noise in the air as a packet, the real packet may be missed before the receiving end determines it as a false alarm, thereby reducing system performance. In the case of low signal-to-noise ratio (SNR), delay correlation is most susceptible to noise interference and affects the accuracy of packet detection. In order to reduce the probability of false alarms, the improvement of delay correlation will be a key. Summary of the invention

[0004] One embodiment of the present disclosure is to provide a packet detection method. The packet detection method includes: receiving a wireless communication signal; calculating a delay correlation function of the wireless communication signal; calculating a delay correlation output value and a threshold value according to the delay correlation function; and determining whether the wireless communication signal meets a feature of a wireless network packet according to the delay correlation output value and the threshold value.

[0005] Another embodiment of the present disclosure is to provide a communication device. The communication device includes a transceiver circuit and a processor. The transceiver circuit is used to receive a wireless communication signal. The processor is used to calculate a delay correlation function of the wireless communication signal, calculate a delay correlation output value and a threshold value according to the delay correlation function, and determine whether the wireless communication signal meets a feature of a wireless network packet according to the delay correlation output value and the threshold value.

[0006] Therefore, according to the technical implementation of the present disclosure, the embodiments of the present disclosure provide a packet detection method and a communication device, which achieves the effect of combined detection by simultaneously considering the information of amplitude and phase. Because the output and threshold are both derived from the delay correlation of the same source, compared with the traditional approach, it is less affected by the input signal strength, interference size, noise, etc., and is therefore more applicable to different noise environment conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to make the above and other purposes, features, advantages and embodiments of the present invention more clearly understood, the following descriptions of the accompanying drawings are given below:

[0008] Figure 1 is a schematic diagram of a communication device according to some embodiments of the present disclosure;

[0009] Figure 2 is a flow chart of a packet detection method according to some embodiments of the present disclosure;

[0010] Figure 3 is a schematic diagram of constellation points of a delayed correlation function of Gaussian white noise according to some embodiments of the present disclosure;

[0011] Figure 4 is a schematic diagram of constellation points of a delay correlation function of a short training sequence packet of a wireless network according to some embodiments of the present disclosure; and

[0012] Figure 5 is a schematic diagram of a processor according to some embodiments of the present disclosure.

[0013] Explanation of symbols

[0014] 100…communication device

[0015] 110…Transceiver circuit

[0016] 130…Processor

[0017] 200…Packet detection method

[0018] S210 to S270…Steps

[0019] 300…Constellation Points

[0020] 400…Constellation Points

[0021] 132…1st Circuit

[0022] 134…Second Circuit

[0023] 136…Comparison circuit

[0024] 132A…Average calculation circuit

[0025] 132C…Square calculation circuit

[0026] 132D…Multiplication factor calculation circuit

[0027] 134A...Square calculation circuit

[0028] 134B…Average calculation circuit

[0029] 134D…Multiplication factor calculation circuit

[0030] OV1, OV2, OV3…output circuit DETAILED DESCRIPTION

[0031] The following disclosure provides many different embodiments or examples for implementing different features of the present invention. The elements and configurations in the specific examples are used to simplify the present disclosure in the following discussion. Any examples discussed are only used for illustrative purposes and do not limit the scope and significance of the present invention or its examples in any way.

[0032] Figure 1 1 is a schematic diagram of a communication device 100 according to some embodiments of the present disclosure. The communication device 100 includes a transceiver circuit 110 and a processor 130. The transceiver circuit 110 is coupled to the processor.

[0033] See also Figure 2 In order to better understand the content of the present disclosure, the detailed operation of the communication device 100 will be combined with Figure 2 The embodiments shown in FIG. Figure 2 FIG. 2 is a flow chart of a packet detection method 200 according to some embodiments of the present disclosure. It is worth noting that the packet detection method 200 can be applied to the same or similar Figure 1 For simplicity of description, the following will be described based on some embodiments of the present disclosure. Figure 1 The packet detection method 200 is described using the embodiment in the example, but the present disclosure does not Figure 1 The application of the embodiments in is limited.

[0034] Figure 2 is a flow chart of a packet detection method 200 according to some embodiments of the present disclosure.

[0035] Step S210 : Receive wireless communication signals. In some embodiments, step S210 is performed by the transceiver circuit 110 .

[0036] Step S230: Calculate the delay correlation function of the wireless communication signal. In some embodiments, step S210 is performed by the processor 130. In some embodiments, the delay correlation function C(t) is as follows:

[0037]

[0038] In the delay correlation function C(t) as described above, a i is the weighting value of the ith antenna, r i,nis the wireless communication signal received by the ith antenna at the nth time point, τ is the period of an STF short training field, N rx is the total number of antennas of the transceiver circuit 110. It should be noted that r i,n The wireless communication signal is represented in multiple forms including real and imaginary parts, including size (amplitude) and phase information, which is well known to those skilled in the art and will not be described in detail here. * is the conjugate complex number of r. From the above formula, those skilled in the art can know that the function C(t) is a complex function, which contains information about magnitude and phase.

[0039] For the convenience of illustration and description, the following will be rx =1, a0=1 as an example, so the delay correlation function C(t) can be rewritten as:

[0040]

[0041] It should be noted that this disclosure does not refer to N rx =1, a0=1 is a limitation, and Ct will be used to represent C(t) hereinafter.

[0042] Please read first Figure 3 . Figure 3 FIG. 3 is a schematic diagram of a constellation signal 300 of a delayed correlation function of Gaussian white noise according to some embodiments of the present disclosure. Figure 3 As shown, the distribution of the constellation points of the noise in the delay correlation function is randomly distributed in the whole circle. That is, for the noise, the phase of its delay correlation function is randomly distributed between 0 and 2π.

[0043] Please read first Figure 4 . Figure 4 FIG. 4 is a schematic diagram of a constellation signal 400 of a delay correlation function of a short training sequence packet of a wireless network according to some embodiments of the present disclosure. Figure 4 As shown, the constellation point distribution of the delay correlation function of the wireless network short training sequence packet is concentrated near a specific angle, and the above angle is highly correlated with the carrier frequency offset (CFO). That is, for the wireless network short training sequence packet, the phase distribution of its delay correlation function is concentrated near a specific angle.

[0044] in accordance with Figure 3 and Figure 4The distribution diagram and probability statistics concept can be used to obtain the following method to determine whether it is noise or wireless network packets. The received wireless communication signal r i,n If it is pure noise, then according to the delay correlation function C t The calculated mean value (mean) E[C t ] will be smaller than its variance Var[C t In this case, |E[C t ]| 2 <Var[C t ]. On the other hand, i,n If it is a short training sequence packet of a pure wireless network, the average value E[C t ] will be greater than its variation value Var[C t In this case, |E[C t ]| 2 >Var[C t ]. Therefore, if the received wireless communication signal satisfies |E[C t ]| 2 >Var[C t ] This feature indicates that a short training sequence packet of a wireless network may be received, that is, a wireless network packet may be received. It should be noted that this embodiment takes a short training sequence as an example, but the present invention is not limited to this. As long as there is a periodic sequence in the wireless network packet, the method of the present invention is applicable.

[0045] Variation value Var[C t ] is expressed as follows, where L is the time length parameter:

[0046]

[0047] Average value E[C t ] is expressed as follows, where L is the time length parameter:

[0048]

[0049] As mentioned above, we can use the judgment formula |E[C t ]| 2 <Var[C t ] or |E[C t ]| 2 >Var[C t ] Determine whether the received wireless communication signal is noise or a wireless network packet. From the above judgment formula, it can be seen that in this embodiment, whether calculating the average value or the variation value, the delay correlation function C is directly used. t The calculation is performed, so the delay correlation function C is taken into account tOn the contrary, the prior art uses the delay correlation function C t Size | C t | to judge the received signal, without considering the delay correlation function C t The phase of the noise can be easily misjudged as a wireless network packet.

[0050] In some embodiments, the above judgment formula further includes a parameter α. For example, In this formula, when the square of the average value |E[C t ]| 2 Greater than the parameter α and the variation value Var[C t ] of the product α·Var[C t ] is determined to be a possible wireless network packet, otherwise it is considered that the received signal may be noise or other unnecessary signals. In the case of determining that a wireless network packet may be detected, other existing judgment methods (such as matching filter output value) can be combined for final judgment, which can greatly reduce the misjudgment of existing judgment methods. In some embodiments, when it is determined that the received wireless communication signal may be a wireless network packet, it is directly determined to be a wireless network packet.

[0051] The above judgment formula can be further calculated as follows:

[0052]

[0053]

[0054] In the above formula, is the delay-related output value, and In the above formula, both sides (delay correlation output value and threshold) come from the delay correlation function C of the same signal. t Therefore, the setting of the parameter α value will not be affected by the input signal strength, interference size, noise, etc.

[0055] Please refer back to Figure 2 Step S250: Calculate the delay-related output value and the threshold value according to the delay-related function. In some embodiments, Figure 2 It is executed by the processor 130 .

[0056] Specifically, in some embodiments, the processor 130 calculates a plurality of delayed sampling values ​​C within a time length according to the delayed correlation function C(t). tFor example, assuming that the time length parameter L is 2, the processor 130 obtains the delayed sampling values ​​C0 and C1 according to the delay correlation function C(t), and calculates the average value of the delayed sampling values ​​C0 and C1. Then, the processor 130 calculates the delayed sampling value C t The square of the average value of the delay-related output value is obtained

[0057] On the other hand, in some embodiments, the processor 130 calculates a plurality of delayed sample values ​​C according to the delayed correlation function C(t). t The square of the power is used to obtain multiple power sampling values. Multiple power sampling values Take the average value and then convert the power sampling value The average value and threshold parameter Multiply to get the threshold In some embodiments, the threshold parameter The value of is between 0 and 1. When the threshold parameter When the value of is 1, the threshold is In this case, the processor 130 calculates a plurality of power sampling values ​​according to the delay correlation function C(t). The average value of is the threshold.

[0058] For example, assuming the threshold parameter The value of is 1, the time length parameter L is 2, and the processor 130 obtains a plurality of delayed sampling values ​​C according to the delay correlation function C(t). t The square of the power is used to obtain multiple power sampling values. Calculate multiple power samples The average value of

[0059] Step S270: Determine whether the wireless communication signal meets the characteristics of a wireless network packet based on the delay-related output value and the threshold. In some embodiments, step S270 is performed by the processor 130. In some embodiments, step S270 determines whether the wireless communication signal is a wireless network packet or noise based on the delay-related output value and the threshold. In some embodiments, when the delay-related output value is Greater than threshold When , it is determined that the wireless communication signal may be a wireless network packet. On the other hand, when the delay-related output value Not greater than the threshold , it is determined that the wireless communication signal may be noise.

[0060] See also Figure 5 . Figure 51 is a schematic diagram of a processor 130 according to some embodiments of the present disclosure. The processor 130 includes a first circuit 132, a second circuit 134, and a comparison circuit 136. In terms of connection relationship, the first circuit 132 and the second circuit 134 are respectively coupled to the comparison circuit 136. It should be noted that, Figure 5 The processor 130 shown is for illustration only and the present disclosure is not limited thereto.

[0061] The first circuit 132 includes an average calculation circuit 132A, a square calculation circuit 132C, a multiplication rate calculation circuit 132D, and an output circuit OV1. The average calculation circuit 132A is used to calculate at least one delayed sampling value C t The average calculation circuit 132A outputs the calculated average value to the square calculation circuit 132C. The square calculation circuit 132C calculates the square of the average value. The output circuit OV1 is used to transmit the value calculated by the square calculation circuit 132C to the multiplication calculation circuit 132D. The multiplication calculation circuit 132D is used to transmit the delayed sampling value C t The square of the average value of is multiplied by a multiplier value. In some embodiments, the multiplier calculation circuit 132D multiplies the delayed sampling value C t The square of the average value of is multiplied by a factor value of 1 to obtain the delay-related output value. Next, the first circuit 132 delays the relevant output value Sent to the comparison circuit 136.

[0062] The second circuit includes a square calculation circuit 134A, an average calculation circuit 134B, a multiplication rate calculation circuit 134D, an output circuit OV2, and an output circuit OV3. The square calculation circuit 134A is used to convert the delayed sample value C t Perform square operation to obtain power sample value The output circuit OV2 is used to transmit the value calculated by the square calculation circuit 134A to the average calculation circuit 134B, and the average calculation circuit 134B is used to calculate the power sampling value. The output circuit OV3 is used to transmit the value calculated by the average calculation circuit 134B to the multiplication calculation circuit 134D, and the multiplication calculation circuit 134D is used to multiply the value transmitted by the output circuit OV3 by the threshold parameter. In some embodiments, the multiplication calculation circuit 134D multiplies the power sampling value The average value and value of Multiply the threshold parameter by to obtain the threshold Next, the first circuit 132 sets the threshold Sent to the comparison circuit 136.

[0063] The comparison circuit 136 is used to compare the delay-related output values Is it greater than the threshold? Then, the comparison result is output to determine whether the wireless communication signal meets the characteristics of the wireless network packet.

[0064] The wireless network packets mentioned above may be wireless local area network (WLAN) packets, orthogonal frequency division multiple access (OFDMA) packets, etc. However, the embodiments of the present disclosure are not limited to the above, and packets transmitted through a wireless network are within the scope of the present disclosure.

[0065] In some embodiments, the processor 130 may be a server, circuit, central processing unit (CPU), microprocessor (MCU) or other circuits with equivalent functions, such as storage, calculation, data reading, receiving signals or information, transmitting signals or information, etc. In some embodiments, the transceiver circuit 110 may be a circuit with receiving signals or information, transmitting signals or information, or other equivalent functions.

[0066] From the above-mentioned embodiments of the present disclosure, it can be seen that the embodiments of the present disclosure provide a packet detection method and a communication device, which achieve the effect of combined detection by simultaneously considering the size (amplitude) and phase information. Because the delay correlation output value and the threshold value are all from the same source of delay correlation, compared with the traditional approach, it is less affected by the input signal strength, interference size, noise, etc., and is therefore more applicable to different noise environment conditions. The embodiments of the present disclosure improve the accuracy of packet detection when the delay correlation is interfered by noise.

[0067] In addition, the above examples include sequential exemplary steps, but the steps do not have to be performed in the order shown. Performing the steps in different orders is within the scope of the present disclosure. Within the concept and scope of the embodiments of the present disclosure, the steps may be added, replaced, changed in order and / or omitted as appropriate.

[0068] Although the present disclosure has been disclosed in the above embodiments, it is not intended to limit the present disclosure. Any person skilled in the art can make various changes and modifications without departing from the concept and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be based on what is defined in the claims.

Claims

1. A packet detection method, comprising: receiving a wireless communication signal; Calculate a delay correlation function C(t) of the wireless communication signal, where t is time. t represents C(t); Calculating a delay-related output value and a threshold value according to the delay-related function; and Determining whether the wireless communication signal satisfies a feature of a wireless network packet according to the delay-related output value and the threshold, wherein: The delay-related output value is The threshold is α is a parameter, is the threshold parameter, L is the time length parameter, When the delay-related output value is greater than the threshold, it is determined that the wireless communication signal meets the characteristic of the wireless network packet.

2. The packet detection method according to claim 1, wherein: The delay correlation function C(t) is as follows: In the delay correlation function C(t), a i is the weight value of the ith antenna, r i,n is the wireless communication signal received by the ith antenna at the nth time point, τ is the period of an STF short training sequence, N rx is the total number of antennas in the transceiver circuit, r * is the complex conjugate of r.

3. The packet detection method according to claim 1, wherein: The delay-related output value and the threshold are calculated according to the square value of the average value of the delay-related function and the variation value calculated from the delay-related function, wherein: The variation value Var[C t The formula of ] is as follows: The average value E[C t The formula of ] is as follows: When the square value of the average value of the delay correlation function is greater than α times the variation value, the judgment formula is calculated as follows:

4. The packet detection method of claim 1, wherein calculating the delay-related output value comprises: Calculating an average value of a plurality of delayed sample values ​​according to the delay correlation function; and A square value of the average value of the plurality of delayed sample values ​​is calculated to obtain the delay-related output value.

5. The packet detection method as claimed in claim 1, wherein calculating the threshold comprises: Calculating a plurality of delayed sampling values ​​according to the delayed correlation function; Calculating a plurality of square values ​​of the delayed sample values ​​to obtain a plurality of power sample values; Calculating an average value of the power sampling values; and The average value of the power sample values ​​is compared with the threshold parameter Multiply to get the threshold.

6. The packet detection method as claimed in claim 1, further comprising: When the delay correlation output value is not greater than the threshold, the wireless communication signal is determined to be a noise.

7. A communication device, for executing the packet detection method according to any one of claims 1 to 6, the communication device comprising: a transceiver circuit for receiving a wireless communication signal; and A processor is used to calculate a delay correlation function of the wireless communication signal, calculate a delay correlation output value and a threshold value according to the delay correlation function, and determine whether the wireless communication signal meets a feature of a wireless network packet according to the delay correlation output value and the threshold value, wherein: The delay correlation output value and the threshold value are calculated based on a square value of a mean value of the delay correlation function and a variation value calculated from the delay correlation function.

8. The communication device as claimed in claim 7, wherein the processor is further configured to calculate an average value of a plurality of delayed sample values ​​according to the delay correlation function, and calculate a square value of the average value of the plurality of delayed sample values ​​to obtain the delay correlation output value.

9. The communication device as claimed in claim 7, wherein the processor is further used to calculate a plurality of delay sampling values ​​according to the delay correlation function, calculate a plurality of square values ​​of the delay sampling values ​​to obtain a plurality of power sampling values, and calculate an average value of the power sampling values, wherein the processor is further used to multiply the average value of the power sampling values ​​by a threshold parameter to obtain the threshold value.

10. The communication device as claimed in claim 7, wherein when the delay-related output value is greater than the threshold, the processor is further used to determine that the wireless communication signal is the wireless network packet, and when the delay-related output value is not greater than the threshold, the processor is further used to determine that the wireless communication signal is a noise.

11. The communication device of claim 7, wherein the processor comprises: a comparison circuit for comparing the delay-related output value with the threshold; A first circuit comprising: an average calculation circuit for calculating a first average value of at least one delayed sample value according to the delay correlation function; a square calculation circuit, used for calculating a first square value of the first average value; and a multiplication rate calculation circuit, used for multiplying the first square value by a multiplication rate value to obtain the delay-related output value; and A second circuit comprising: a square calculation circuit, for calculating at least one delayed sample value according to the delay correlation function, and calculating at least one second square value of the at least one delayed sample value; an average calculation circuit for calculating a second average value of the at least one second square value; and A multiplication rate calculation circuit is used for multiplying the second average value by a threshold parameter to obtain the threshold.

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