TWI681656B - Software-defined radio system for package detection and package detection method - Google Patents

Abstract

Provided is a software-defined radio (SDR) system for packet detection, including a transmitter, respectively configuring a preamble and a postamble at a start position and an end position of a packet before transmitting the packet; a receiver, detecting if the packet exists in the air or in a channel based on the preamble and the postamble. When the preamble is detected, the receiver stores a received signal in memory; when the postamble is detected, the receiver stops storing the received signal in the memory and transmits the received signal to a computing device. Moreover, the present disclosure also provides a packet detection method suitable for a SDR system.

Description

Packet detection software defined radio system and packet detection method

This disclosure relates to a software-defined radio, in particular to a design of prefixes and post-sync signals suitable for packet detection of software-defined radios.

Nowadays, software-define radio (SDR) platforms on the market are very popular. In addition to being directly connected to computers, software-defined radio platforms (SDR) can directly set various parameters for software-defined radio platforms through software interfaces. In the transmission mode, the software or program can be used to quickly define the signal format to be transmitted, and in the reception mode, the calculation and processing procedures for the received signal can be directly defined in the software. The hardware part of the software-defined radio platform includes front-end modules (including filters, modulators/demodulators, RF modules, etc.) and computer communication interfaces, so that users do not need to design or implement front-end modules. Quickly construct a communication system, while retaining design flexibility, and can also retain the programmable parameter settings of the front module for users to customize the definition on the software side.

Therefore, the software-defined radio platform is very suitable for applications such as fundamental frequency algorithm development, channel measurement, and rapid establishment of communication systems. It also provides low-cost and easy-to-use options.

However, when developing a software-defined radio platform, it still retains the original advantages of the general software-defined radio, and also provides users with program-controlled research and development, such as network communication protocols and various handshaking mechanisms for communication ), automatic retransmission mechanism, etc. In these program-controlled applications, the software-defined radio must not only have the ability to send and receive signals, but also must be able to detect and receive a complete segment of packets, so that the start of each packet and the At the end, the platform must also have duplex capability. Therefore, the design and detection mechanisms at the beginning and end of the packet are particularly important.

The present disclosure provides a software defined radio (SDR) system for packet detection and a packet detection method suitable for software defined radio.

The software-defined radio system for packet detection disclosed in this disclosure includes: a transmitting end, which is respectively configured with a preamble and a postamble at the beginning of the packet of the signal and before the signal is transmitted; End position; and a receiving end, detecting whether the packet is in the air or in the channel according to the prefix and the post-sync signal. When the prefix sync signal is detected, the receiving end stores the signal in the memory, when When the post-sync signal is detected, the receiving end stops storing the signal in the memory and sends the signal to a computing device.

According to the preferred embodiment of the present disclosure, the points of the prefix synchronization signal and the post synchronization signal are fixed, and are not related to the baud-rate or sampling rate set by the software-defined radio system. The maximum bandwidth that the prefix synchronization signal and the post synchronization signal can occupy is defined as Bmax, and the bandwidth that the prefix synchronization signal and the post synchronization signal actually occupy is defined as B, and the designed prefix synchronization The preferred embodiment of the signal and the post-sync signal is fixed B/Bmax. An implementable embodiment can refer to FIG. 2, the prefix synchronization signal and the post-synchronization signal are both fixed at N points, and the modulation method of OFDM is used to design a sequence of M points on subcarriers representing different frequencies. The N-point IFFT can generate the N-point prefix synchronization signal and the post-sync signal. The software defines the transmission baud-rate, sampling rate, carrier frequency, transmission attenuation and reception gain set by the radio system using the same M and N values. In the detection circuit of the receiving end, under different sampling rate settings, the down-sampling (downsample) of the same magnification can be used for the prefix sync signal and the post sync signal, and then the down-sampled sync signal can be detected Whether it exists in the received signal, therefore, the same detection circuit can be used to detect the prefix synchronization signal and the post synchronization signal under different sampling rate settings.

According to another preferred embodiment of the present disclosure, the points of the prefix synchronization signal and the post synchronization signal are fixed, and are not related to the transmission baul-rate or sampling rate set by the software-defined radio system. The maximum bandwidth that the prefix synchronization signal and the post synchronization signal can occupy is defined as Bmax, and the bandwidth actually occupied by the prefix synchronization signal and the post synchronization signal is defined as B, the designed prefix synchronization signal The preferred embodiment of the post-synchronization signal does not fix r=B/Bmax, and r decreases as the transmission baud-rate or sampling rate set by the software-defined radio system increases, and vice versa. For a practical implementation, refer to FIG. 5. The prefix synchronization signal and the post synchronization signal are both fixed at N points. Using the modulation method of OFDM, the sequence of M points is designed to be placed on subcarriers representing different frequencies. The N-point IFFT can generate the N-point prefix synchronization signal and the post-sync signal. The value of M will increase as the transmission baud-rate or sampling rate set by the software-defined radio system increases. In the receiving end detection circuit, after the pre-synchronization signal and the post-synchronization signal are down-sampled, it is then detected whether the down-sampled synchronization signal exists in the received signal and is supported under different sampling rate settings The downsampling ratio is different, but the difference in the design of the detection circuit is very small, but it allows the lower downsampling ratio to maintain the detection performance with a lower downsampling ratio, and the high sampling rate setting can be further The down-sampling ratio of the prefix synchronization signal is increased to reduce the computational complexity of the detection circuit.

According to yet another preferred embodiment of the present disclosure, in the transmitting end, the prefix synchronization signal and the post synchronization signal may be composed of a plurality of symbols with a length of N points connected in series, and in the plurality of symbols The plurality of sequences on the can be the same or different, and the plurality of sequences are selected by the group identification code; in the receiving end, the receiving end first detects the first of the plurality of symbols of length N points Symbols, when the detection is successful, the receiver continues to detect the second symbol. After the detection is successful, it is determined whether the time difference between the second symbol and the first symbol is detected correctly , If it is correct, continue to detect the next symbol, and detect sequentially, until all the plural symbols are detected successfully, it means that the prefix synchronization signal or the post synchronization signal is successfully detected.

In addition, the packet detection method of the present disclosure includes the following steps: before transmitting the signal, the transmitting end configures a prefix synchronization signal and a post synchronization signal at the start position and end position of the packet of the signal; the receiving end according to the prefix Detect whether the packet is in the air or in the channel with the post-sync signal; if the prefix sync signal is detected, cause the receiver to store the signal in memory; and if the post-sync signal is detected At the time, the receiving end stops storing the signal in the memory and sends the signal to a computing device.

The packet detection method of the present disclosure may include a simultaneous maximum amplification method of groups. The amplification method includes the following steps: the prefix synchronization signal and the post synchronization signal may be connected in series at the transmitting end A plurality of symbols with a length of N points, the plurality of sequences on the plurality of symbols may be the same or different, and the plurality of sequences is selected by a group identification code; and in the receiving end, the receiving The terminal first detects the first symbol in the plurality of N-point symbols. When the detection is successful, the receiver continues to detect the second symbol. When the detection is successful, the second symbol is judged. Whether the time difference between the detection of the first symbol and the first symbol is correct. If it is correct, the next symbol will continue to be detected in sequence, until all the plural symbols are successfully detected, it means the prefix The sync signal or the post-sync signal is successfully detected.

In order to make the above-mentioned features and advantages of the present disclosure more comprehensible, the following examples are given in detail with reference to the accompanying drawings. The additional features and advantages of the present disclosure will be partially explained in the following description, and these features and advantages will be partially apparent from the description, or may be learned through the practice of the present disclosure. The features and advantages of the present disclosure are recognized and achieved by means of the elements and combinations particularly pointed out in the scope of the patent application. It should be understood that both the foregoing general description and the following detailed description are merely exemplary and explanatory, and are not intended to limit the scope claimed by this disclosure.

The embodiments of the present disclosure will be described below with specific implementation forms. Those familiar with this technology can easily understand the advantages and effects of the disclosure by the contents disclosed in this specification, and can also be implemented or applied by different specific implementation forms.

The present disclosure proposes a software-defined radio (SDR) system for packet detection, so that the software-defined radio (SDR) system can ensure the reception of complete packet data when receiving.

Figure 1 shows the start and end formats of the packets disclosed in this disclosure. At the transmitting end 10, the user-defined transmission signal (marked as data in Figure 1) will first transmit a sequence of numbers, called P1, and then a small piece of blank space will be transmitted. This blank space makes P1 not at the receiving end. It will cause interference to the user signal due to the multipath effect of the channel. At the same time, it can still receive the complete user signal under the influence of the channel effect and the clock error of the transmitting and receiving ends. After the user signal is transmitted, a small piece of blank space is immediately followed by a sequence of numbers, called P2. The receiving end 12 uses the detection of P1 and P2 to know the start and end of the user signal in order to store the complete User signals are provided for users to process on the software side. In addition, each software-defined radio platform can provide users to independently set their parameters such as group ID, sampling rate, carrier frequency, transmission attenuation, and reception gain. It also supports one-to-many platform transmission. Multiple groups of transmitting and receiving terminals in communication are operating simultaneously.

As shown in FIG. 1, the software-defined radio system for packet detection provided by the present disclosure includes a transmitting terminal 10, which is configured with a preamble P1 and a post synchronization before transmitting a signal (data), respectively. The signal (postamble) P2 is at the start position and end position of the packet of the signal; and a receiving end 12 detects whether the packet exists in the air or in the channel based on the prefix and the post-synchronization signal, where, When the prefix synchronization signal P1 is detected, the receiving end 12 stores the signal in the memory; when the rear synchronization signal P2 is detected, the receiving end 12 stops storing the signal in the memory, and Send the signal to a computing device.

The software-defined radio system for packet detection provided by this disclosure includes two design structures for synchronization signals, which are detailed as follows:

( Examples 1)

As shown in Figure 2, the prefix synchronization signal and the post synchronization signal are N-point symbols, which are composed of M-point sequences in frequency (the minimum frequency subcarrier is located in the center), regardless of the sampling rate and carrier frequency , Transmission attenuation, receiving gain, etc. parameter settings all use the same M and N values, the content of the M point sequence is only related to the group identification code (group ID). Between different groups, the way that the prefix synchronization signal avoids interference can be divided into the following two situations:

(1) Between groups with the same sampling rate, the prefix synchronization signals are distinguished by different sequences, that is to say, the transmitting end 20 with the group identification code a corresponds to the sequence x to form its prefix synchronization signal, and the receiving end 22 If the group identification code is set to a, it corresponds to the use of the receiving end 22 composed of the sequence x for detection, and the detection is successful, and the group identification code is set to b, the receiving end corresponds to the receiving end 22 composed of the sequence y. If the detection is performed, the detection cannot be successful. Therefore, the prefix synchronization signal of group a will not cause a false alarm to group b.

(2) Between groups with different sampling rates, the characteristics of this prefix synchronization signal structure will no longer affect each other, that is, the sending end 20 with the sampling rate set to f0 and the group identification code set to a, corresponding to the sequence x If the group identification code is set to f1 and the sampling rate is set to f1, even if the group identification code is set to a, the group identification code composed of the sequence x will be used for detection. .

This design makes it possible to set only the same sampling rate among all groups that are operating at the same time. It is necessary to set different group IDs to avoid signal interference. Groups with different sampling rates will not cause false alarms. , So it can greatly increase the total number of groups operating simultaneously. In addition, under any sampling rate setting, the receiver 22 can support the prefix synchronization signal after N/M times downsampling and then perform matching detection. Therefore, the same matching circuit can be used under different parameter settings, but different The sampling rate uses M-point sequences, which can share the same sequence set, and reduce the complexity of the matching circuit and reduce the memory requirement.

Taking the actual application scenario as an example, if the software-defined radio platform provides three sampling rates for users to set: 30.72 MHz, 61.44 MHz, 122.88 MHz, and each of the three sampling rates may have up to 64, 50, and 32 groups operating at the same time. Considering the cost of hardware, it is hoped that the clock speed of the matching hardware can operate up to 30.72 MHz. Using the method of Embodiment 1, when selecting the Zadoff-Chu sequence, at least 64 lengths of the Zadoff-Chu sequence are required. A total of 64 sequences can be provided by using different root indexes, which corresponds to the group identification code group ID 0~ 63 can be set; and because the maximum sampling rate of 122.88 MHz can be supported, and the maximum operating clock of matching hardware is 30.72 MHz, the sub-sampling ratio of matching hardware is 122.88/30.72 = 4, making the symbol length of the prefix synchronization signal At least 64×4 = 256, therefore, M in Figure 2 is 64, and N is 256. The performance test of Example 1 is shown in Figures 3A, 3B, and 3C. Figure 3A shows that in the same group, receive The end uses a matching detection of 4 times the sampling rate to correctly detect the probability of the prefix synchronization signal. Figure 3B shows two groups with the same sampling rate (the two groups set different group identification codes, that is, corresponding to different root index of the Zadoff-Chu sequence), the sending end causes the probability of false alarms of the receiving end of another group. Figure 3C shows the two groups with different sampling rates (the two groups set the same group ID, that is, The Zadoff-Chu sequence corresponding to the same root index), the sending end causes the probability of false alarms of the receiving end of another group. Specifically, as shown in Figure 3A, it can be seen that under various sampling rate settings, the signal-to-noise ratio (SNR) of -3dB or more can completely detect the prefix synchronization signal, which is suitable for various communication-related applications, such as , Synchronization mechanism, frequency offset, data encoding and decoding, etc., and Figure 3B shows that using different Zadoff-Chu sequences can completely avoid the influence of prefix synchronization signals of other groups, and the signal to noise ratio as low as -11dB will not cause false alarms. In the case of Figure 3C, it is verified that groups with different sampling rates, even if the same Zadoff-Chu sequence is used, will not affect each other. It is worth mentioning that the implementation of the detection circuit of the receiving end in the disclosed embodiment 1 can refer to FIG. 4, the N-point prefix synchronization signal is first subjected to an R-fold down-sampling circuit, and after the down-sampling is obtained, N/R Point synchronization signal, and then use N/R point matching detection to detect whether the N/R point synchronization signal exists in the received signal. For embodiment 1, N is 256, and three sampling rate settings: 30.72 MHz, Both 61.44 MHz and 122.88 MHz can use R=4 to design the detection circuit. Therefore, all sampling rate settings can use the same set of detection circuits.

( Examples 2)

As shown in FIG. 5, Embodiment 2 of the present disclosure includes a transmitting end 30 and a receiving end 32. Regardless of the parameter settings, the prefix synchronization signal and the post-synchronization signal are N-point symbols, which constitute the prefix synchronization signal. The sequence covers a fixed bandwidth. In the second embodiment, the number of sequence points placed on the frequency will vary according to the sampling rate setting. As shown in Figure 5, if the sequence length at the sampling rate of 61.44 MHz is M, then when the sampling rate is set to 30.72 MHz and 122.88 MHz, the sequence length at the frequency becomes 2M and M/2, respectively. Between different groups, the way that the prefix synchronization signal avoids interference can be divided into the following two situations:

(1) Between groups with the same sampling rate, prefix synchronization signals are distinguished by different sequences.

(2) Between groups with different sampling rates, the characteristics of this prefix synchronization signal structure will not affect each other, and there is no need to use different sequences to distinguish them.

This design is the same as in the first embodiment, and no additional sequence is needed to avoid interference between groups with different sampling rates, which can greatly increase the total number of groups operating simultaneously. At a higher sampling rate setting, for sub-sampling matching, it can provide a higher sub-sampling ratio than Example 1, which is suitable for further streamlining the hardware cost, or suitable for supporting a higher sampling rate setting in the future; Under the low sampling rate setting, the sequence accounts for a large proportion of the total bandwidth. For the matching result of the receiver 32, the matching noise can be reduced, which is suitable for operating in a lower signal-to-noise environment, and the matching circuit complexity is originally It is lower and does not need to accommodate high-power sub-sampling matching at the expense of matching efficiency.

Taking the actual application scenario as an example, if the software-defined radio platform provides three sampling rates for users to set: 30.72 MHz, 61.44 MHz, 122.88 MHz, and each of the three sampling rates may have up to 64, 50, and 32 groups operating at the same time. Considering the cost of hardware, it is hoped that the clock speed of the matching hardware can operate up to 15.36 MHz. Using the method of Example 2, when selecting the Zadoff-Chu sequence, the three sampling rate settings individually require Zadoff-Chu sequences with lengths of 128, 64, and 32, and each can support up to 128, 64, and 32 groups to operate simultaneously; It supports a sampling rate of 122.88 MHz, and the maximum operating clock of the matching hardware is 15.36 MHz. The sub-sampling ratio of the matching hardware is 122.88/15.36 = 8, so that the symbol length of the prefix synchronization signal is at least 32×8 = 256. In Figure 5, M is 64 and N is 256. The performance test of Example 2 is shown in Figures 6A, 6B, and 6C. Figure 6A shows the probability of correctly detecting the prefix synchronization signal in the same group. The sampling rate is 122.88 MHz and 30.72 MHz group performance, the receiver uses a sampling rate of 15.36 MHz for matching detection, Figure 6B shows that the two sampling rates are 122.88 MHz between groups (two group settings Different group IDs, that is, Zadoff-Chu sequences corresponding to different root indexes), the sending end causes the probability of false alarms of the receiving end of another group. Figure 6C shows the sampling rate between the two groups of 122.88 MHz and 30.72 MHz. (The two groups set the same group ID, that is, the Zadoff-Chu sequence corresponding to the same root index, but due to the different sampling rate, the length of the Zadoff-Chu sequence used by the two is different), the sending end causes the receiving end of another group The probability of false alarms. Specifically, as shown in Figure 6A, it can be seen that because the lower the sampling rate, the higher the ratio of the sequence to the total bandwidth, the lower the matching noise, so the sampling rate of 30.72 MHz can support the sampling rate of 122.88 MHz. Lower signal-to-noise ratio environment, but the 122.88 MHz sampling rate can support matching detection of up to 8 times the sub-sampling ratio. The measured results can correctly detect the range of signal-to-noise ratio, and can also be applied to most communication-related applications. . Figure 6B shows that using different Zadoff-Chu sequences can completely avoid the influence of prefix synchronization signals of other groups, while Figure 6C verifies groups with different sampling rates, even if the same root index of Zadoff-Chu sequences is used, and the sequence frequency The same width will not affect each other. It is worth mentioning that the implementation of the detection circuit of the receiving end of the disclosed embodiment 2 can refer to FIG. 4, the N-point prefix synchronization signal is first subjected to an R times downsampling circuit, and after the downsampling is obtained, N/R Point synchronization signal, and then use the N/R point matching detection to detect whether the N/R point synchronization signal exists in the received signal. For Example 2, N is 256, and three sampling rate settings: 30.72 MHz, 61.44 MHz and 122.88 MHz can use R=2, 4 and 8 to design the detection circuit respectively. When the sampling rate is set to 30.72 MHz, the smaller R can get better detection performance, and when the sampling rate is set to 122.88 MHz , R=8 can reduce the operating clock of the detection circuit to 122.88/8=15.36 MHz, instead of operating at the clock of 122.88 MHz, greatly reducing the computational complexity of the detection circuit.

( Examples 3)

In order to be suitable for various communication-related applications and support future communication standards for higher data rates, the software-defined radio system sampling rate of this disclosure can be set by the user and will support a very high sampling rate. In this case, the receiver must perform high-sampling sub-sampling matching. When the length of the prefix synchronization signal is fixed, the higher the sub-sampling ratio to be supported, the shorter the length of the sequence configured on the frequency, which will cause The maximum number of groups that can support simultaneous operations is reduced, and the lower the ratio of the sequence to the total bandwidth, the matching noise at the receiving end is increased. Even if the length of the prefix synchronization signal is increased, it cannot be solved. Therefore, as shown in Figure 7, this The disclosure also provides a method of amplifying the maximum amount of support for simultaneously operating groups. This method can also use the designs of Embodiments 1 and 2 of the present disclosure. Figures 8A and 8B respectively show the expansions of the disclosed operating groups at the same time. Block diagram and detection flowchart for the method of maximum support. The method includes: if the symbol length of the original prefix synchronization signal is N, the number of sequence points placed on the frequency is M, and correspondingly, M different sequences can be generated, supporting up to M groups to operate at the same time. Number of groups supported, L symbols of N points with the same structure can be concatenated together to form a prefix synchronization signal/post-synchronization signal. The sequence of the L symbols can be the same or different, but they are all from the original M Different sequences are selected so that at most ^ML groups can be supported to operate at the same time, first set the parameter i to 1 (step S70), that is, match from the first symbol, so the receiving end matches the first symbol first, When the matching is successful, the receiving end continues to match the second symbol (step S71). After the matching is successful, it is judged whether the time difference between the peak of the second symbol and the first symbol is correct (step S72), if correct , Then continue to match the next symbol in sequence (step S73), until all L symbols are detected successfully, it means that the prefix synchronization signal or the post synchronization signal is successfully detected (step S74), and finally obtain Detect the start and end positions of the data (step S75). The advantage of this amplification method is that: each symbol in the prefix synchronization signal/post synchronization signal is selected from the same sequence set, no additional sequence needs to be defined, and the memory on the hardware will not be increased Demand, in addition, adding one more symbol in series can quickly expand the support of the largest simultaneous operation of groups.

Taking the amplification method of the present disclosure applied to an actual situation as an example, if the design method of Embodiment 1 is used, the length of the prefix synchronization signal is 256 symbols, and the length of the Zadoff-Chu sequence with length 64 is centrally arranged in the frequency domain. At this time, it can support up to 4 times the sub-sampling rate matching and support up to 64 groups to operate at the same time. If you want to further expand to support the simultaneous operation of 1000 groups at the same time, use the disclosed group support volume amplification method (implementation Example 3) The two prefix synchronization signals are concatenated. The Zadoff-Chu sequence of the two prefix synchronization signals can be the same or different, so it can support up to 64 ² = 4096 groups at the same time, without changing the original prefix synchronization signal And without defining additional sequences, the maximum number of groups that can be operated simultaneously is greatly expanded. At the receiving end, according to the detection process in Figure 8B, each time a sample point is received, the second prefix synchronization signal is matched, and the first prefix synchronization is also performed on the received sample delayed by 256 points. For signal matching, when both matching detections are successfully detected, it is determined to be the start of the user's signal.

In addition, if you want to use software-defined radio in a very low signal-to-noise ratio environment, then the threshold used for matching decisions will be relatively lowered. At this time, false alarms will begin to occur, and the false alarms must be reduced as much as possible. Probability, this disclosure tests for two false alarms: (1) Detecting packets in the same group, the detection is successful but the starting position of the user signal obtained is wrong, (2) Detecting packets in other groups, the detection is successful , Mistaken for the user signal of the group. The false alarm rates in both cases are shown in Figures 9A and 9B. Those who do not use the disclosed group support expansion method have only one 256-point symbol as the prefix synchronization signal, and use the disclosed group support expansion. If the method is added, the two 256-point symbols connected in series are used as the prefix synchronization signal. Both cases use the design of Example 1, as can be seen from Figures 9A and 9B, using the group support disclosed in this disclosure Volume amplification method can greatly reduce the false alarm rate.

The above-mentioned embodiments only exemplify the principles, features and effects of this disclosure, and are not intended to limit the scope of implementation of this disclosure. Anyone who is familiar with this skill can do this without departing from the spirit and scope of this disclosure. The embodiment is modified and changed. Any equivalent changes and modifications made using the contents disclosed in this disclosure should still be covered by the scope of the patent application. Therefore, the scope of protection of rights disclosed in this disclosure should be as listed in the scope of patent application.

10, 20, 30‧‧‧Send

12, 22, 32‧‧‧ receiver

S70 to S75‧‧‧ steps

Figure 1 is a schematic diagram of the disclosed software-defined radio system for packet detection; Figure 2 is a schematic diagram of the disclosed software-defined radio system for packet detection (Example 1); Figures 3A, 3B, and 3C show this The performance test results of the disclosed embodiment 1; FIG. 4 shows a block diagram of the detection circuit of the receiving end disclosed in the present disclosure; FIG. 5 shows a block diagram of the software-defined radio system (embodiment 2) of the disclosed packet detection; Figures 6A, 6B, and 6C show the results of the performance test of Example 2 of the present disclosure; Figure 7 shows a schematic diagram of the amplification method (Example 3) of the maximum supported amount of groups operating simultaneously in the present disclosure; Figure 8A shows Block diagram of the disclosed amplification method (Example 3); FIG. 8B shows a detection flowchart of the disclosed amplification method (Example 3); and FIGS. 9A and 9B show used and unused disclosure The comparison test results of the amplification method for the false alarm rate.

20‧‧‧Transmitter

22‧‧‧Receiver

Claims (12)

A software-defined radio system for packet detection includes: a transmitting end, which is configured with a prefix synchronization signal and a post synchronization signal at the start and end positions of the packet of the signal before transmitting a signal; and a The receiving end detects the channel. When the prefix synchronization signal is detected, the receiving end stores the signal in the memory, and when the post synchronization signal is detected, the receiving end stops The signal is stored in the memory and the signal is sent to a computing device. The software-defined radio system for packet detection as described in item 1 of the scope of the patent application, in which the points of the prefix synchronization signal and the post-sync signal are fixed and not the transmission baud rate set by the software-defined radio system ( baud-rate) or sampling rate. The software-defined radio system for packet detection as described in item 2 of the patent scope, wherein the maximum bandwidth that the prefix synchronization signal and the post synchronization signal can occupy is defined as Bmax, and the prefix synchronization signal and the The bandwidth occupied by the post-sync signal is actually defined as B, r=B/Bmax, r is not related to the transmission baud-rate or sampling rate set by the software-defined radio system. The software-defined radio system for packet detection as described in item 1 of the patent application scope, wherein the sequence on the prefix synchronization signal and the post synchronization signal is selected by a group identification code. The software-defined radio system for packet detection as described in item 2 of the patent scope, wherein the maximum bandwidth that the prefix synchronization signal and the post synchronization signal can occupy is defined as Bmax, and the prefix synchronization signal and the The bandwidth occupied by the post-sync signal is actually defined as B, r=B/Bmax, and r decreases as the transmission baud-rate or sampling rate set by the software-defined radio system increases. The software-defined radio system for packet detection as described in item 1 of the patent application scope, wherein, in the transmitting end, the prefix synchronization signal and the post synchronization signal can be connected in series by a plurality of lengths of N points Composed of symbols, the plural sequences on the plural symbols can be the same or different, and the plural sequences are selected by the group identification code; in the receiving end, the receiving end first detects the plural lengths It is the first symbol of the N-point symbols. When the detection is successful, the receiver continues to detect the second symbol. When the detection is successful, the second symbol and the first symbol are judged. Whether the time gap of successful symbol detection is correct, if it is correct, continue to detect the next symbol in sequence, until all the plural symbols are successfully detected, it means the prefix synchronization signal or the post synchronization signal Successful detection. A packet detection method suitable for a software-defined radio system. The method includes: before transmitting a signal, the transmitting end configures a prefix synchronization signal and a post synchronization signal at the start and end positions of the packet of the signal; The channel is detected by the receiving end; if the prefix synchronization signal is detected, the receiving end is caused to store the signal in the memory; and if the rear synchronization signal is detected, the receiving end is stopped The signal is stored in the memory and the signal is sent to a computing device. The packet detection method as described in item 7 of the patent application scope, wherein the points of the prefix synchronization signal and the post synchronization signal are fixed, and are not related to the transmission baud-rate or sampling rate set by the software-defined radio system . The packet detection method as described in Item 8 of the patent scope, wherein the maximum bandwidth that the prefix synchronization signal and the post synchronization signal can occupy is defined as Bmax, and the prefix The bandwidth occupied by the synchronization signal and the post-sync signal is actually defined as B, r=B/Bmax, r is not related to the transmission baud-rate or sampling rate set by the software-defined radio system. The packet detection method as described in item 7 of the patent application scope, wherein the sequence on the prefix synchronization signal and the post synchronization signal is selected by the group identification code. The packet detection method as described in item 8 of the patent scope, wherein the maximum bandwidth occupied by the prefix synchronization signal and the post-sync signal is defined as Bmax, and the prefix synchronization signal and the post-sync signal In fact, the occupied bandwidth is defined as B, r=B/Bmax, and r decreases as the transmission baud-rate or sampling rate set by the software-defined radio system increases. The packet detection method as described in item 7 of the patent application scope, wherein, in the transmitting end, the prefix synchronization signal and the post synchronization signal may be composed of a plurality of symbols with a length of N points connected in series, The plurality of sequences on the plurality of symbols can be the same or different, and the plurality of sequences are selected by the group identification code; in the receiving end, the receiving end first detects the plurality of lengths of N points The first symbol in the symbol, when the detection is successful, the receiving end continues to detect the second symbol, when the detection is successful, the second symbol and the first symbol are detected Whether the time gap of success is correct. If it is correct, continue to detect the next symbol in sequence, until all the multiple symbols are detected successfully, it means that the prefix synchronization signal or the post synchronization signal is successfully detected.

Images