CN116800378A - Multi-type frame identification and judgment device and method for meteor trail communication - Google Patents
Multi-type frame identification and judgment device and method for meteor trail communication Download PDFInfo
- Publication number
- CN116800378A CN116800378A CN202310748878.2A CN202310748878A CN116800378A CN 116800378 A CN116800378 A CN 116800378A CN 202310748878 A CN202310748878 A CN 202310748878A CN 116800378 A CN116800378 A CN 116800378A
- Authority
- CN
- China
- Prior art keywords
- frame
- frame type
- type
- decision
- interval
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 36
- 230000005540 biological transmission Effects 0.000 claims abstract description 7
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 238000001914 filtration Methods 0.000 claims description 3
- 238000005070 sampling Methods 0.000 claims description 2
- 230000001360 synchronised effect Effects 0.000 abstract description 3
- 238000004364 calculation method Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000013500 data storage Methods 0.000 description 3
- 238000009432 framing Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 2
- 230000000977 initiatory effect Effects 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
Landscapes
- Synchronisation In Digital Transmission Systems (AREA)
Abstract
The invention discloses a device and a method for identifying and judging multiple types of frames of meteor trail communication, belonging to the technical field of burst communication; means for multi-type frame identification: a matched filter for estimating the position of the frame header during transmission, one or more specific frame type identifiers for performing a comparison of the frame header distance with a set distance, and a frame type determiner for determining the received frame type. The invention only needs one set of frame head related matching circuit, and the method can more stably and efficiently finish the task of frame type identification under the condition of more frame types. In addition, the method strengthens the synchronous constraint condition, and the problem of mutual interference of a plurality of frame header sequences does not exist, so that the method has lower misjudgment and misdetection probability under the condition of low signal-to-noise ratio.
Description
Technical Field
The invention relates to the technical field of burst communication, in particular to a method and a device for identifying and judging multiple types of frames suitable for meteor trail communication.
Background
Meteor trail communication is a burst communication mode with a random channel. The channels of meteor trail communication occur at random times and are also random in duration. For randomness of the channel, meteor trail communication systems generally improve channel utilization by sending frames that match the current channel conditions. Typically these frames have a similar structure, but the amount of data carried by each frame is different. Therefore, the meteor trail receiver can only correctly identify the type of the received frame and process the received frame accordingly to resolve the correct data.
The traditional frame type identification method is to insert a section of frame header before the data section, and distinguish the frame types through the difference of the frame header. The key point is to select a group of sequences with weaker cross-correlation as frame heads and allocate a special frame head for each frame. In the traditional frame type identification method, the receiving end carries out parallel correlation operation on the received signals according to the characteristic of poor correlation among different frame heads. When the correlation calculation result of a certain path is larger than a preset threshold, the receiving end considers that the work of frame type identification is finished. However, this method has the disadvantage of limited number of optional sequences, which seriously affects the flexibility of framing at the transmitting end. In addition, in the process of correlation calculation, the receiver needs to set a corresponding matching circuit for each frame header, so that the traditional method needs to occupy more hardware resources, and certain difficulty is caused to implementation of the scheme. In addition, mutual interference exists between sequences, and under the condition of low signal-to-noise ratio, the synchronous judgment result of the traditional frame type identification method is more easily affected by noise, so that the problems of misjudgment, omission and false detection of the received frame are caused.
Disclosure of Invention
The invention aims to solve the problems that the number of sequences in the background is limited, the number of frames is large, the false judgment and error detection probability is high under the condition of low signal to noise ratio, and provides a multi-type frame identification and judgment method and device applied to meteor trail communication, which can meet the requirements of framing and judging at any length under the condition of small additional transmission cost, thereby more effectively utilizing limited channel resources. And the method only needs one set of frame head related matching circuit, and can more stably and efficiently finish the task of frame type identification under the condition of more frame types. In addition, the method strengthens the synchronous constraint condition, and the problem of mutual interference of a plurality of frame header sequences does not exist, so that the method has lower misjudgment and misdetection probability under the condition of low signal-to-noise ratio.
The aim of the invention is achieved by the following technical scheme:
a multi-type frame identification and judgment device suitable for meteor trail communication comprises a digital down converter, a low-pass filter and a data memory which are connected in sequence, wherein the device is used for performing front-end processing on an obtained baseband signal; the system also comprises a matched filter, a frame type identifier and a frame type decision device;
the received intermediate frequency signal is processed by sampling, down-conversion, low-pass filtering and the like to obtain a complex baseband signal, and the complex baseband signal is sent into a matched filter by a demodulator; performing correlation operation on the received signal and a local frame header sequence in a matched filter to estimate the position of a frame header in the transmission process and output a correlation peak indicating the position of the frame header in a complex baseband signal; the frame type identifier judges the spacing between frame heads through the correlation peak, and outputs a frame type identification signal when the spacing between the frame heads accords with a set distance; the frame type judging device judges the type of the currently received frame according to the frame type identification signal output by the frame identifier; when the frame type identification is successful, information for performing subsequent signal processing is output, and the frame type decider resets the operation states of all the frame type deciders.
Further, at least one or more frame type identifiers are arranged, and a plurality of frame type identifiers are connected in parallel; the frame type identifiers are different in frame type judgment interval length; both ends of each frame type identifier are respectively connected to the matched filter and the frame type decision device.
A method for identifying and judging multi-type frames suitable for meteor trail communication is realized by the device suitable for identifying and judging multi-type frames for meteor trail communication, which comprises the following specific steps:
step 1, a transmitting end inserts a section of frame header before and after a data section of a baseband signal respectively, and the distance between the two sections of frame header is the length T of the data section;
step 2, the matched filter of the receiving end continuously works, and the received data is calculated;
step 3, the frame type identifier sets the frame type decision initial time to T0,
step 4, the decision interval for identifying the frame type identifier signaled in step 1 is (T0, T0+T ]; the frame type identifier looks for the maximum value in the range of (T0, T0+T), the position of the maximum value is T1;
step 5, judging whether the T1 position meets a certain frame type judgment constraint condition, if the T1 position does not meet the corresponding frame type judgment constraint condition, performing step 6; if the position of T1 meets the decision constraint condition of the corresponding frame type, taking T1 as a correlation peak to carry out step 7;
step 6, the frame type identification fails, the judgment initial time T1 of the frame type at the next time is taken as T0, and the steps 4 to 5 are repeated;
step 7, the frame type identification is successful, and the judgment information of the frame type is output to be used for carrying out the information of the subsequent signal processing; and taking the decision initial time T1 of the next time frame type as T0, and repeating the steps 4 to 5.
Further, judging whether the position of the correlation peak meets the judgment constraint condition of a certain frame type or not is as follows, wherein the position of the correlation peak belongs to a successful judgment at the tail part of a frame type judgment interval to which the correlation peak belongs; the position of the correlation peak does not belong to the failure decision at the end of the frame type decision interval to which it belongs.
Further, the frame type identifier compares the distance between two sections of frame heads with the length of the judging section, and when the frame head distance is equal to the length of the judging section, the frame type identifier considers that the frame of the corresponding type is received, otherwise, the frame of the type is considered to be not received temporarily.
Further, the frame type identifier firstly sets a frame type judgment initial time and a frame type judgment interval; searching maximum value in frame type judging interval, judging whether the maximum value position in interval can be used as correlation peak or not: when the distance between two adjacent correlation peaks is equal to the frame length set by a certain frame type identifier, the corresponding frame type identifier outputs an identification success mark, otherwise, the frame type identifier outputs a temporary unrecognized success mark; and finally updating the frame type judgment initial time and the frame type judgment interval.
Compared with the prior art, the invention has the advantages that:
compared with the traditional method, the method has the advantages that only one section of frame head at the tail of the data section is added, so that the method can be almost ignored for data transmission; the use of a matched filter is reduced, and the complexity of related calculation is greatly reduced; and the synchronization constraint condition is also enhanced, and the reliability of the algorithm is ensured. The method has simple algorithm and stable and reliable performance, can solve the problems of limited sequence number and difficult selection in the traditional method under the condition of small transmission cost and calculation cost, and meets the requirements of framing and distinguishing at any length, thereby more efficiently utilizing limited channel resources.
Drawings
Fig. 1 is an application example diagram of a multi-type frame recognition and decision apparatus of the present invention.
Fig. 2 is a block diagram of a multi-type frame recognition and decision apparatus of the present invention.
Fig. 3 is a frame structure used in the multi-type frame identification, decision method of the present invention.
Fig. 4 is a flow chart of the operation of the multi-type frame identifier of the present invention.
Detailed Description
The following describes in further detail the embodiments of the present invention with reference to the drawings and examples.
A multi-type frame identification and decision device suitable for meteor trail communication comprises a matched filter, one or more specific frame type identifiers and a frame type decision device.
The matched filter is used for carrying out correlation operation on the received signal and the local frame header sequence so as to estimate the position of the frame header in the transmission process.
The frame type identifier is used for comparing the frame head distance with the set distance, and outputting a frame type identification signal when the frame head distance accords with the set distance.
The frame type decider is used for deciding the received frame type according to the frame type identification signal output by the frame identifier, and outputting related information for a subsequent processing module to correctly finish signal processing.
The invention adopts the technical scheme that:
the invention employs a specific frame structure comprising: two pieces of frame header and one piece of data. Two sections of frame heads are respectively inserted in the front and the back of the data section, the frame head at the front end of the data section is a frame head 1, and the frame head at the rear end of the data section is a frame head 2. The frame type decision basis of the present invention is that the distance between the frame header 1 and the frame header 2 is not the same in different frames, so the type of the current frame can be decided by the distance between the frame header 1 and the frame header 2.
The frame head distance is calculated by using a larger correlation peak generated when the frame head in the received signal is matched with a locally stored frame head sequence, and the distance between two sections of frame heads can be known according to the distance between the two correlation peaks. Thus, the method can distinguish between different frames as long as the lengths of the data segments are different.
Furthermore, if two frames with the same length need to be distinguished, a sequence with excellent cross-correlation with the sequence can still be used as a new frame header, and the difficulty of frame header selection is reduced.
At the heart of a method and apparatus for multi-type frame identification, decision for meteor trail communication is one or more frame type identifiers arranged in parallel, which differ in: frame type decision intervals of different sizes are set. The following describes a workflow of a method and a device for identifying and judging multi-type frames suitable for meteor trail communication by taking a frame type identifier corresponding to a certain frame length as an example:
1. the transmitting end inserts a section of frame head respectively in front of and behind the data section of the baseband signal, wherein the distance between the two sections of frame heads is assumed to be T;
2. the matched filter of the receiving end continuously works, and the correlation calculation is carried out on the received data;
3. the frame type identifier corresponding to the frame length of the signaling data section sets the frame type judgment initial time as T0, and the frame type judgment interval is [ T0, T0+T ];
4. the frame type identifier searches for a maximum value in the range of [ T0, T0+ T ], the position of the maximum value is T1, and the T1 is assumed to be a correlation peak in the range of [ T0, T0+ T ];
5. judging whether the T1 position meets certain frame type judgment constraint conditions, and executing the corresponding step 6 or step 7 according to the judgment result;
6. if the position of the new maximum value meets the judgment constraint condition of the frame type, the frame type is successfully identified, the next moment is a new frame type judgment initial moment, a new frame type judgment interval is established according to the next moment, and the step 4 is executed;
7. if the position of the new maximum value does not meet the judgment constraint condition of the frame type, the frame type identification fails, the frame type judgment initial time is updated to be T1, the frame type judgment interval is [ T1, T1+ T ], and the next step is executed;
8. the frame type identifier searches the maximum value in the range of [ T0+ T, T1+ T ], the position of the maximum value is T2, and the T2 is assumed to be a correlation peak in the range of [ T1, T ];
9. judging whether the T2 position meets the judgment constraint condition of a certain frame type, and executing the corresponding step 6 or step 7 according to the judgment result;
the decision constraint for determining whether the position of the new maximum value satisfies a certain frame type is as follows:
and (3) success judgment: the position of the new maximum is at the end of the frame type decision interval to which it belongs.
Failure judgment: the position of the new maximum is not at the end of the frame type decision interval to which it belongs.
The following is a more specific description:
fig. 1 is an application example diagram of a multi-type frame recognition and decision device in the background art. The resulting complex baseband signal is processed after the digital down-converter, the low pass filter and the data storage. The input a of the digital down-converter is a discretized digital intermediate frequency signal which is sampled by an analog-to-digital conversion module for the received intermediate frequency signal. The type of the received frame and the position of the data storage device are output to the channel estimation device, so that the channel estimation device can completely extract the data to be processed from the correct data storage device. Only if the data to be processed is extracted correctly, the channel estimation device can make accurate estimation to the channel parameters, and the channel compensation device can make effective compensation to the received signals. After channel compensation, the received signal is fed in a form conforming to the channel decoder, which outputs the original information.
Fig. 2 is a block diagram of a multi-type frame recognition and decision apparatus of the present invention. The first step of the invention at the receiving end is to process as matched filtering. The receiving end sends the complex baseband signal obtained after the front end processing into a matched filter for processing. The complex baseband signal obtained after the front-end processing is matched with the selected frame header, and when the signal is completely matched with the frame header, the matched filter outputs a larger correlation peak, so that the position of the correlation peak indicates the position of the frame header in the complex baseband signal.
The core of the invention is one or more frame type identifiers which are arranged in parallel after the matched filter, and the frame type identifier is characterized in that a frame type judgment interval needs to be specified. The length of the frame type decision interval depends on the distance between two frame headers of the frame to be detected, so that the essential difference of different frame type identifiers is that the frame type decision interval length set for them is different.
The decision basis for the frame type identifier is the distance between frame header 1 and frame header 2. The distance between frame heads is calculated by utilizing the principle that a correlation peak is generated when the frame heads in the received signal are matched with a locally stored frame head sequence: when the distance between two adjacent correlation peaks is equal to the frame length set by the frame type identifier, the frame type identifier outputs an identification success mark; when the unequal distance between two adjacent correlation peaks is equal to the frame length set by the frame type identifier, the frame type identifier outputs a temporary unrecognized success flag.
The key of the invention is a frame type decision device which is responsible for summarizing the output result of the frame type identifier, judging the type of the currently received frame, and resetting the working states of all the frame type decision devices when the frame type identification is successful.
The frame structure adopted by the invention is the basis of the realization of the invention. In fig. 3, two frame headers and a data segment sandwiched between the two frame headers form a fixed frame structure in the present invention, the frame header at the front end of the data segment is frame header 1, and the frame header at the rear end of the data segment is frame header 2, where the frame header 1 and the frame header 2 are two identical sequences. The present invention requires that the data segments of different frames be of different lengths. For the case of the data segment length, a sequence having excellent cross-correlation with the present sequence may be used as a new frame header. In the present invention, the transmitting end transmits the frame header 1, the data segment and the frame header 2 in sequence.
Fig. 4 shows a flowchart of the operation of the multi-type frame identifier of the present invention, and details the operation of a specific multi-type frame identifier of the present invention.
Step 1: the multi-type frame identifier sets a frame type decision initial time.
This time, which is arbitrarily chosen and is typically the first clock cycle for which the device is operating normally, is denoted T0. The frame type decision initial time position is the position of the first correlation peak assumed by the method, the position is not necessarily the position of the true correlation peak, and the selection of the position does not influence the realization of the method. After setting the frame type decision initial time, the multi-type frame identifier may define a first frame type decision interval, the size of which is determined by the length of the frame to be identified. And setting the length of the frame to be identified as T, and setting the first frame type judgment interval as [ T0, T0+T ].
Step 2: the multi-type frame identifier finds the highest value in the whole frame type decision interval.
By scanning the entire frame type decision interval, the multi-type frame identifier selects the maximum value within the frame type decision interval [ T0, t0+t ], assuming that the maximum value position in the interval is at T1.
Step 3: the multi-type frame identifier makes a decision on the location of the maximum value within the interval.
After obtaining the maximum value of the current frame type judgment interval, the multi-type frame identifier judges whether the maximum value position meets the current frame type judgment constraint condition, and at this time, the judgment can have two cases:
frame type identification was successful: if the position of T1 is at t0+t in the frame type decision interval, it is explained that the distance of the two assumed correlation peaks is equal to the length set by the multi-type frame identifier. Thus, at T0 is the first correlation peak and at T1 (t0+t) is the second correlation peak, so that the currently received signal can be decided as this type of frame. The multi-type frame identifier outputs a frame type matching success signal, sets the next moment as a new frame type judgment initial moment, establishes a new frame type judgment interval according to the new frame type judgment initial moment, and executes step 2.
Frame type identification failure: if the position of T1 is not at t0+t in the frame type decision interval, it is explained that the distance of the two assumed correlation peaks is not equal to the length set by the multi-type frame identifier. Thus, it is not possible that there is a true first correlation peak at T0, but there is a possible first correlation peak at T1, and it can be decided that there is no frame of this type or that complete data is currently received. The multi-type frame identifier outputs that the frame type matching is a failure signal, sets the time T1 as a new frame type decision initial time, and executes step 4.
Step 4: the multi-type frame identifier updates the frame type decision interval.
The multi-type frame identifier defines a new frame type decision interval T1, t1+t according to the new frame type decision initiation. Since the section [ T1, t0+t ] has been scanned and the peak position is T1, if the transmitting end transmits the frame of this type, the position of the next peak cannot be in the section [ T1, t0+t ], so the multi-type frame identifier only needs to scan the section [ t0+t, t1+t ].
Step 5: the multi-type frame identifier finds the highest value within a partial frame type decision interval.
The multi-type frame identifier selects the maximum value within the frame type decision interval [ t0+t, t1+t ], assuming that the maximum value position in the interval is at T2.
Step 6: the multi-type frame identifier makes a decision on the location of the maximum value within the interval.
After obtaining the maximum value of the current frame type judgment interval, the multi-type frame identifier judges whether the maximum value position meets the current frame type judgment constraint condition, and at this time, the judgment can have two cases:
frame type identification was successful: if the position of T2 is at t1+t in the frame type decision interval, it is explained that the distance of the two assumed correlation peaks is equal to the length set by the multi-type frame identifier. Thus, at T1 is the first correlation peak and at T2 (t1+t) is the second correlation peak, so that the currently received signal can be decided as this type of frame. The multi-type frame identifier outputs a frame type matching success signal, sets the next moment as a new frame type judgment initial moment, establishes a new frame type judgment interval according to the new frame type judgment initial moment, and executes step 2.
Frame type identification failure: if the position of T2 is not at t1+t in the frame type decision interval, it is explained that the distance of the two assumed correlation peaks is not equal to the length set by the multi-type frame identifier. Thus, it is not possible that there is a true first correlation peak at T1, but there is a possible first correlation peak at T2, and it may be decided that there is no frame of this type or that complete data is currently received. The multi-type frame identifier outputs that the frame type matching is a failure signal, updates the first correlation peak position register T1, assigns a value of T2 to it, i.e. the T2 position is the start point T1 of the next decision interval, and performs step 4.
Claims (6)
1. A multi-type frame identification and judgment device suitable for meteor trail communication comprises a digital down converter, a low-pass filter and a data memory which are connected in sequence, wherein the device is used for performing front-end processing on an obtained baseband signal; the method is characterized by further comprising a matched filter, a frame type identifier and a frame type judging device;
the received intermediate frequency signal is processed by sampling, down-conversion, low-pass filtering and the like to obtain a complex baseband signal, and the complex baseband signal is sent into a matched filter by a demodulator; performing correlation operation on the received signal and a local frame header sequence in a matched filter to estimate the position of a frame header in the transmission process and output a correlation peak indicating the position of the frame header in a complex baseband signal; the frame type identifier judges the spacing between frame heads through the correlation peak, and outputs a frame type identification success signal when the spacing between the frame heads accords with a set distance; the frame type judging device judges the type of the currently received frame according to the frame type identifying signal output by the frame identifying device; when the frame type identifier outputs a frame type identification success signal, the frame type decision device outputs information used for the subsequent processing of the type frame, and resets the working states of all the frame type decision devices.
2. A multi-type frame identification and decision device suitable for meteor trail communication according to claim 1, wherein the frame type identifier is provided with at least one or more, and a plurality of frame type identifiers are connected in parallel; the frame type identifiers are different in frame type judgment interval length; both ends of each frame type identifier are respectively connected to the matched filter and the frame type decision device.
3. A method for identifying and judging multi-type frames suitable for meteor trail communication, which is realized by the device for identifying and judging multi-type frames suitable for meteor trail communication according to claim 1 or 2, and is characterized by comprising the following specific steps:
step 1, a transmitting end inserts a section of frame header before and after a data section of a baseband signal respectively, and the distance between the two sections of frame header is the length T of the data section;
step 2, the matched filter of the receiving end continuously works, and the received data is calculated;
step 3, the frame type identifier sets the frame type decision initial time to T0,
step 4, the decision interval for identifying the frame type identifier signaled in step 1 is (T0, T0+ T), the frame type identifier searches the maximum value in the range of (T0, T0+ T), the position of the maximum value is T1, the starting position of the decision interval of other frame type identifiers is also T0, the decision interval length is determined by the length of the frame data segment to be identified, the maximum value is searched in each decision interval, and the positions of the maximum values in each decision interval are all called T1;
step 5, each frame type identifier judges whether the T1 position in the judging section meets a certain frame type judging constraint condition, if the T1 position does not meet the judging constraint condition of the corresponding frame type, step 6 is carried out; if the position of T1 meets the decision constraint condition of the corresponding frame type, taking T1 as a correlation peak to carry out step 7;
step 6, the frame type identification fails, the judgment initial time T1 of the frame type at the next time is taken as T0, and the steps 4 to 5 are repeated;
step 7, the frame type identification is successful, and the judgment information of the frame type is output to be used for carrying out the information of the subsequent signal processing; and taking the decision initial time T1 of the next time frame type as T0, and repeating the steps 4 to 5.
4. A method for identifying and judging multiple types of frames suitable for meteor trail communication according to claim 3, wherein judging whether the position of the correlation peak satisfies the judgment constraint condition of a certain frame type is as follows, the position of the correlation peak belongs to a successful judgment at the tail of the frame type judgment interval to which the correlation peak belongs; the position of the correlation peak does not belong to the failure decision at the end of the frame type decision interval to which it belongs.
5. A method of multi-type frame identification and decision for meteor trail communication according to claim 3, wherein the frame type identifier compares the distance between two frame headers with the length of the decision interval, and when the frame header distance is equal to the length of the decision interval, the frame type identifier considers that a frame of the corresponding type is received, otherwise, the frame of the type is considered to be not received temporarily.
6. A method for multi-type frame identification and decision for meteor trail communication according to claim 3, wherein the frame type identifier first sets a frame type decision initial time and a frame type decision interval; searching maximum value in frame type judging interval, judging whether the maximum value position in interval can be used as correlation peak or not: when the distance between the maximum values in two adjacent intervals is equal to the frame length set by the frame type identifier, the corresponding frame type identifier outputs a successful identification mark, otherwise, the frame type identifier outputs a temporary unsuccessful identification mark; and finally updating the frame type judgment initial time and the frame type judgment interval.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310748878.2A CN116800378A (en) | 2023-06-25 | 2023-06-25 | Multi-type frame identification and judgment device and method for meteor trail communication |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310748878.2A CN116800378A (en) | 2023-06-25 | 2023-06-25 | Multi-type frame identification and judgment device and method for meteor trail communication |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116800378A true CN116800378A (en) | 2023-09-22 |
Family
ID=88035898
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310748878.2A Pending CN116800378A (en) | 2023-06-25 | 2023-06-25 | Multi-type frame identification and judgment device and method for meteor trail communication |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116800378A (en) |
-
2023
- 2023-06-25 CN CN202310748878.2A patent/CN116800378A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101331742B1 (en) | A method and an apparatus for synchronising a receiver timing to transmitter timing | |
| US20060140293A1 (en) | Method for detecting signal and estimating symbol timing | |
| CN106535138B (en) | Synchronization method and device for time division multiple access self-organizing network | |
| US8306173B2 (en) | Clock regeneration circuit | |
| CN112532371A (en) | Parallel frame synchronization method, sending end, receiving end and low-earth-orbit satellite communication system | |
| CN110649940B (en) | Fast frequency hopping system for restraining forwarding interference in capturing stage | |
| RU2650496C1 (en) | Method and device for detection of the frame header of a multichannel signal | |
| US6542563B1 (en) | Reception method and receiver for digital radio communication system | |
| CN102480455B (en) | Detecting method and detecting device for primary synchronization signals in long-term evolution system | |
| CN116800378A (en) | Multi-type frame identification and judgment device and method for meteor trail communication | |
| CN101252390B (en) | Frame synchronization method and realizing device based on paralleling tactic | |
| US20230031301A1 (en) | Radio synchronization | |
| US20020150118A1 (en) | Communication system, method and signal for time-slot-coded data transmission | |
| CN101635583A (en) | Anti-phase deviation demodulation method of narrow-band high-speed frequency hopping system | |
| CN111162858B (en) | Segmented signal synchronization method and device, terminal equipment and storage medium | |
| CN104023386B (en) | Transmitting terminal, receiving terminal and its frame synchornization method, frame synchronization system | |
| CN104283824A (en) | OFDM-based symbol synchronization position searching method | |
| CN111245543B (en) | Method and device for searching air interface data synchronization head | |
| CN113572540A (en) | Unmanned aerial vehicle graph signaling signal identification method and system based on correlation domain detection | |
| CN105072678B (en) | A kind of signal sync bit detection method of the low false alarm rate of low complex degree | |
| CN114916053B (en) | Blind synchronization method of voice frame | |
| CN111163032A (en) | Method for rapidly capturing weak signal under high dynamic condition | |
| CN115632921B (en) | Coding auxiliary blind frame synchronization method and system based on threshold detection | |
| US6600793B1 (en) | Minimal overhead early late timing recovery | |
| CN111181598B (en) | Method for timing synchronization of burst spread spectrum signal with extremely low signal-to-noise ratio |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |