A method, device and medium for bidirectional predictive coding of telemetry code stream for ground transmission

Abstract

The embodiment of the present invention provides a method, device and medium for bidirectional predictive coding of telemetry code stream for ground transmission, which divides the original data into a key group, a forward group and a bidirectional group, and performs intra-group coding on the key group, performs inter-group coding on the forward group using its preceding key group as a reference group, and selects one of the key groups and the forward group on the preceding and following sides of the bidirectional group for inter-group coding to achieve lossless compression of the telemetry code stream and fully utilize the bandwidth of the transmission channel.

Description

Technical Field

[0001] The present invention relates to the field of aerospace telemetry, and in particular to a method, device and medium for bidirectional prediction coding of telemetry code stream for ground transmission. Background Art

[0002] After the telemetry data is sent to the ground measurement and control station through the space-based and ground-based links, the measurement and control station sends it to the data center or the launch mission undertaker for processing through the network as the main transmission link. Currently, after receiving the data, the ground measurement and control station will send the original data code stream to the receiver in the original full-frame manner through network unicast or multicast, which has low bandwidth utilization of the transmission link.

[0003] In the process of implementing the present invention, the applicant discovered that there are at least the following problems in the prior art:

[0004] The existing telemetry data encoding method has low bandwidth utilization of the transmission link. Summary of the invention

[0005] The embodiments of the present invention provide a method, device and medium for bidirectional predictive coding of telemetry code stream for ground transmission, which solves the problem of low bandwidth utilization of transmission links in existing telemetry data coding methods.

[0006] To achieve the above-mentioned purpose, on the one hand, an embodiment of the present invention provides a method for bidirectional predictive coding of a telemetry code stream for ground transmission, comprising:

[0007] The original data is grouped into groups according to the sampling values ​​of each group being a first preset number, to obtain a plurality of groups, and a sequence number is set for each group in sequence;

[0008] For all groups, a key group is marked every second preset number of groups, a forward group is marked every third preset number of groups between two adjacent key groups, and groups other than the forward group between two adjacent key groups are marked as bidirectional groups;

[0009] For each key group, performing a first intra-group encoding on the key group to obtain a key group code corresponding to the key group;

[0010] For each forward group, taking the most recent key group before the forward group as the reference group of the forward group, performing first inter-group coding on the forward group to obtain a forward group code corresponding to the forward group;

[0011] For each bidirectional group, a group is selected from the nearest key group and the nearest forward group before and after the bidirectional group according to a preset condition as a reference group of the bidirectional group, and the forward group is subjected to a second inter-group coding according to the reference group of the bidirectional group to obtain a bidirectional group code corresponding to the bidirectional group;

[0012] Arranging key group codes corresponding to all key groups, forward group codes corresponding to all forward groups, and bidirectional group codes corresponding to all bidirectional groups in the order of the key groups, the forward groups, and the bidirectional groups in the plurality of groups as the bidirectional predictive codes;

[0013] The bidirectional predictive coding also includes the sequence number of the reference group corresponding to each bidirectional group in the multiple groups.

[0014] Furthermore, for each key group, performing first intra-group coding on the key group to obtain a key group code corresponding to the key group includes:

[0015] For each key group, predictively encode the key group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the key group and a residual sequence corresponding to the key group, and compress the residual sequence corresponding to the key group by a lossless compression method to obtain a lossless compression code corresponding to the key group;

[0016] The key group code corresponding to the key group includes the s-order prediction coefficient corresponding to the key group and the lossless compression code corresponding to the key group.

[0017] Further, for each forward group, taking the most recent key group before the forward group as the reference group of the forward group, performing first inter-group coding on the forward group to obtain a forward group code corresponding to the forward group includes:

[0018] For each forward group, predictively encode the forward group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the forward group and a residual sequence corresponding to the forward group;

[0019] Taking the most recent key group before the forward group as the reference group of the forward group, obtaining a residual sequence corresponding to the reference group, calculating the difference between the residual sequence corresponding to the reference group and the residual sequence corresponding to the forward group, obtaining a difference sequence corresponding to the forward group, and compressing the difference sequence corresponding to the forward group by a lossless compression method to obtain a lossless compression code corresponding to the forward group;

[0020] The forward group coding corresponding to the forward group includes the s-order prediction coefficient corresponding to the forward group and the lossless compression coding corresponding to the forward group.

[0021] Further, for each bidirectional group, selecting a group from the nearest key group and the nearest forward group before and after the bidirectional group according to a preset condition as a reference group of the bidirectional group, and performing a second inter-group coding on the forward group according to the reference group of the bidirectional group to obtain a bidirectional group code corresponding to the bidirectional group includes:

[0022] For each bidirectional group, predictively encode the bidirectional group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the bidirectional group and a residual sequence corresponding to the bidirectional group;

[0023] Determine the difference between the residual sequence corresponding to each of the key group and the nearest forward group on both sides of the bidirectional group and the residual sequence corresponding to the bidirectional group, obtain the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group, select the difference sequence with the smallest information entropy between the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group as the difference sequence corresponding to the bidirectional group, and compress the difference sequence corresponding to the bidirectional group by a lossless compression method to obtain the lossless compression code corresponding to the bidirectional group;

[0024] The closest key group or the closest forward group corresponding to the difference sequence with the smallest information entropy is used as the reference group of the bidirectional group;

[0025] The bidirectional group code corresponding to the bidirectional group includes: an s-order prediction coefficient corresponding to the bidirectional group, a lossless compression code corresponding to the bidirectional group, and a sequence number of a reference group of the bidirectional group in the plurality of groups.

[0026] Furthermore, the lossless compression method includes Huffman coding.

[0027] On the other hand, an embodiment of the present invention provides a telemetry code stream ground transmission bidirectional prediction coding device, comprising:

[0028] A grouping unit, used for grouping the original data into groups of sampling values ​​of a first preset number each, obtaining a plurality of groups, and setting a sequence number for each group in sequence;

[0029] a marking unit, configured to mark a key group for every second preset number of groups for all groups, mark a forward group for every third preset number of groups between two adjacent key groups, and mark groups other than the forward group between two adjacent key groups as bidirectional groups;

[0030] A key group encoding unit, configured to perform a first intra-group encoding on each key group to obtain a key group code corresponding to the key group;

[0031] A forward group encoding unit, configured to, for each forward group, perform first inter-group encoding on the forward group by taking a key group immediately preceding the forward group as a reference group of the forward group to obtain a forward group code corresponding to the forward group;

[0032] a bidirectional group encoding unit, configured to select, for each bidirectional group, a group from a nearest key group and a nearest forward group before and after the bidirectional group according to a preset condition as a reference group of the bidirectional group, and perform a second inter-group encoding on the forward group according to the reference group of the bidirectional group to obtain a bidirectional group code corresponding to the bidirectional group;

[0033] a bidirectional prediction code acquisition unit, configured to arrange key group codes corresponding to all key groups, forward group codes corresponding to all forward groups, and bidirectional group codes corresponding to all bidirectional groups in the order of the key groups, the forward groups, and the bidirectional groups in the plurality of groups as the bidirectional prediction code;

[0034] The bidirectional predictive coding also includes the sequence number of the reference group corresponding to each bidirectional group in the multiple groups.

[0035] Further, the key group encoding unit is specifically configured to: for each key group, perform predictive encoding on the key group by a linear predictive encoding method to obtain an s-order prediction coefficient corresponding to the key group and a residual sequence corresponding to the key group, and compress the residual sequence corresponding to the key group by a lossless compression method to obtain a lossless compression code corresponding to the key group;

[0036] The key group code corresponding to the key group includes the s-order prediction coefficient corresponding to the key group and the lossless compression code corresponding to the key group.

[0037] Furthermore, the forward group encoding unit comprises:

[0038] A first intra-group coding module is used for performing predictive coding on each forward group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the forward group and a residual sequence corresponding to the forward group;

[0039] a first inter-group coding module, configured to use a most recent key group preceding the forward group as a reference group of the forward group, obtain a residual sequence corresponding to the reference group, calculate a difference between a residual sequence corresponding to the reference group and a residual sequence corresponding to the forward group, obtain a difference sequence corresponding to the forward group, and compress the difference sequence corresponding to the forward group by a lossless compression method to obtain a lossless compression code corresponding to the forward group;

[0040] The forward group coding corresponding to the forward group includes the s-order prediction coefficient corresponding to the forward group and the lossless compression coding corresponding to the forward group.

[0041] Furthermore, the bidirectional group encoding unit comprises:

[0042] A second intra-group coding module is used for performing predictive coding on each bidirectional group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the bidirectional group and a residual sequence corresponding to the bidirectional group;

[0043] A second inter-group coding module is used to determine the difference between the residual sequence corresponding to each of the key group and the nearest forward group on both sides of the bidirectional group and the residual sequence corresponding to the bidirectional group, obtain the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group, select the difference sequence with the smallest information entropy of the difference sequence between the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group as the difference sequence corresponding to the bidirectional group, and compress the difference sequence corresponding to the bidirectional group by a lossless compression method to obtain the lossless compression code corresponding to the bidirectional group;

[0044] The closest key group or the closest forward group corresponding to the difference sequence with the smallest information entropy is used as the reference group of the bidirectional group;

[0045] The bidirectional group code corresponding to the bidirectional group includes: an s-order prediction coefficient corresponding to the bidirectional group, a lossless compression code corresponding to the bidirectional group, and a sequence number of a reference group of the bidirectional group in the plurality of groups.

[0046] On the other hand, an embodiment of the present invention provides a readable storage medium storing a program code corresponding to any one of the methods described above.

[0047] The above technical solution has the following beneficial effects: the technical solution of the present invention adopts a bidirectional prediction coding and decoding method for the telemetry code stream, reduces the code rate through coding, and makes full use of the saved code stream space to improve the bandwidth utilization of the transmission link. Specifically, the compression coding and decoding method combining grouping, inter-frame bidirectional prediction, and Huffman coding is used to improve the efficiency of the link. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 It is a flow chart of a method for bidirectional predictive coding of telemetry code stream ground transmission according to one embodiment of the present invention;

[0050] Figure 2It is a schematic diagram of the architecture of a bidirectional predictive coding device for ground transmission of telemetry code streams according to one embodiment of the present invention;

[0051] Figure 3 This is a schematic diagram of the format of raw data in one embodiment of the present invention;

[0052] Figure 4 It is a schematic diagram of the encoding process of the key group and the forward group in one embodiment of the present invention;

[0053] Figure 5 It is a schematic diagram of the encoding process of a bidirectional group according to one embodiment of the present invention;

[0054] Figure 6 The present invention is a schematic diagram of the grouping and inter-group coding relationship of a method for bidirectional predictive coding of a telemetry code stream for ground transmission according to one embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] On the one hand, if Figure 1 As shown, an embodiment of the present invention provides a method for bidirectional predictive coding of a telemetry code stream for ground transmission, comprising:

[0057] Step S100, grouping the original data into groups of sampling values ​​each having a first preset number to obtain a plurality of groups, and setting a sequence number for each group in sequence;

[0058] Step S101, for all groups, mark a key group every second preset number of groups, mark a forward group every third preset number of groups between two adjacent key groups, and mark the groups between two adjacent key groups except the forward group as bidirectional groups;

[0059] Step S102, for each key group, performing a first intra-group encoding on the key group to obtain a key group code corresponding to the key group;

[0060] Step S103, for each forward group, taking the most recent key group before the forward group as the reference group of the forward group, performing first inter-group coding on the forward group to obtain a forward group code corresponding to the forward group;

[0061] Step S104: for each bidirectional group, according to a preset condition, select a group from the nearest key group and the nearest forward group before and after the bidirectional group as a reference group of the bidirectional group, and perform a second inter-group coding on the forward group according to the reference group of the bidirectional group to obtain a bidirectional group code corresponding to the bidirectional group;

[0062] Step S105, arranging the key group codes corresponding to all key groups, the forward group codes corresponding to all forward groups, and the bidirectional group codes corresponding to all bidirectional groups in the order of the key groups, the forward groups, and the bidirectional groups in the plurality of groups as the bidirectional predictive codes;

[0063] The bidirectional predictive coding also includes the sequence number of the reference group corresponding to each bidirectional group in the multiple groups.

[0064] In some embodiments, the first preset number, the second preset number, and the third preset number can be set according to the data change of the telemetry data in the field to which the original data belongs, for example, by testing a large amount of data to determine the hostile preset number that can achieve the maximum compression rate. Among them, the second preset number is greater than the third preset number. The first intra-group coding realizes lossless compression of the key group, and compresses a continuous section of data in the original data; the first inter-group coding and the second inter-group coding realize the relative changes between the grouped data of a long time span in the original data, and further improve the compression rate by using the similarity of the data between non-adjacent groups. Figure 6 As shown, b is the third preset number, k is the second preset number; the forward group uses the nearest key group in front as a reference, and the bidirectional group selects a group from the nearest key group and the nearest forward group as a reference.

[0065] Furthermore, for each key group, performing first intra-group coding on the key group to obtain a key group code corresponding to the key group includes:

[0066] For each key group, predictively encode the key group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the key group and a residual sequence corresponding to the key group, and compress the residual sequence corresponding to the key group by a lossless compression method to obtain a lossless compression code corresponding to the key group;

[0067] The key group code corresponding to the key group includes the s-order prediction coefficient corresponding to the key group and the lossless compression code corresponding to the key group. The value of s is determined according to the field to which the original data belongs, and is generally 10-12.

[0068] Further, for each forward group, taking the most recent key group before the forward group as the reference group of the forward group, performing first inter-group coding on the forward group to obtain a forward group code corresponding to the forward group includes:

[0069] For each forward group, predictively encode the forward group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the forward group and a residual sequence corresponding to the forward group;

[0070] Taking the most recent key group before the forward group as the reference group of the forward group, obtaining a residual sequence corresponding to the reference group, calculating the difference between the residual sequence corresponding to the reference group and the residual sequence corresponding to the forward group, obtaining a difference sequence corresponding to the forward group, and compressing the difference sequence corresponding to the forward group by a lossless compression method to obtain a lossless compression code corresponding to the forward group;

[0071] The forward group coding corresponding to the forward group includes the s-order prediction coefficient corresponding to the forward group and the lossless compression coding corresponding to the forward group.

[0072] Further, for each bidirectional group, selecting a group from the nearest key group and the nearest forward group before and after the bidirectional group according to a preset condition as a reference group of the bidirectional group, and performing a second inter-group coding on the forward group according to the reference group of the bidirectional group to obtain a bidirectional group code corresponding to the bidirectional group includes:

[0073] For each bidirectional group, predictively encode the bidirectional group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the bidirectional group and a residual sequence corresponding to the bidirectional group;

[0074] Determine the difference between the residual sequence corresponding to each of the key group and the nearest forward group on both sides of the bidirectional group and the residual sequence corresponding to the bidirectional group, obtain the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group, select the difference sequence with the smallest information entropy between the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group as the difference sequence corresponding to the bidirectional group, and compress the difference sequence corresponding to the bidirectional group by a lossless compression method to obtain the lossless compression code corresponding to the bidirectional group;

[0075] The closest key group or the closest forward group corresponding to the difference sequence with the smallest information entropy is used as the reference group of the bidirectional group;

[0076] The bidirectional group code corresponding to the bidirectional group includes: an s-order prediction coefficient corresponding to the bidirectional group, a lossless compression code corresponding to the bidirectional group, and a sequence number of a reference group of the bidirectional group in the plurality of groups.

[0077] Information entropy itself has nothing to do with the encoding method. It is a measure of the amount of information expressed in the source. The calculation method is formula (1):

[0078]

[0079] Among them, P i is the probability of an event occurring, and n is the total number of events. i = -log2(P i ) is the information content of a single event, which is related to P i That is, the greater the probability of an event, the less information it contains, because expected things do not bring much new information. i log2(P i ) is a weighted average of the information of each event, because although low-probability events contain a large amount of information, their probability of occurrence is small.

[0080] Furthermore, the lossless compression method includes Huffman coding.

[0081] In some embodiments, since the information entropy of the residual sequence corresponding to the key group, the difference sequence corresponding to the forward group and the difference sequence corresponding to the bidirectional group is already relatively small, Huffman coding can be used to compress these sequences with relatively small information entropy effectively.

[0082] The embodiments of the present invention have the following technical effects: by adopting a bidirectional prediction coding and decoding method for telemetry code streams, the code rate is reduced through coding, and the saved code stream space is fully utilized to improve the bandwidth utilization of the transmission link. Specifically, the compression coding and decoding method combining grouping, inter-frame bidirectional prediction, and Huffman coding is used to improve the efficiency of the link.

[0083] On the other hand, Figure 2 As shown, an embodiment of the present invention provides a telemetry code stream ground transmission bidirectional prediction coding device, comprising:

[0084] The grouping unit 200 is used to group the original data into groups of sampling values ​​of a first preset number each, to obtain a plurality of groups, and to set a sequence number for each group in sequence;

[0085] The marking unit 201 is used to mark a key group for every second preset number of groups for all groups, mark a forward group for every third preset number of groups between two adjacent key groups, and mark the groups other than the forward group between two adjacent key groups as bidirectional groups;

[0086] A key group encoding unit 202 is used for performing a first intra-group encoding on each key group to obtain a key group code corresponding to the key group;

[0087] A forward group encoding unit 203 is configured to, for each forward group, perform first inter-group encoding on the forward group by taking a key group preceding the forward group as a reference group of the forward group to obtain a forward group code corresponding to the forward group;

[0088] The bidirectional group coding unit 204 is configured to select, for each bidirectional group, a group from the closest key group and the closest forward group before and after the bidirectional group as a reference group of the bidirectional group according to a preset condition, and perform a second inter-group coding on the forward group according to the reference group of the bidirectional group to obtain a bidirectional group code corresponding to the bidirectional group;

[0089] A bidirectional prediction code acquisition unit 205 is used to arrange key group codes corresponding to all key groups, forward group codes corresponding to all forward groups, and bidirectional group codes corresponding to all bidirectional groups in the order of the key groups, the forward groups, and the bidirectional groups in the multiple groups as the bidirectional prediction code;

[0090] The bidirectional predictive coding also includes the sequence number of the reference group corresponding to each bidirectional group in the multiple groups.

[0091] Further, the key group encoding unit 202 is specifically configured to: for each key group, perform predictive encoding on the key group by a linear predictive encoding method to obtain an s-order prediction coefficient corresponding to the key group and a residual sequence corresponding to the key group, and compress the residual sequence corresponding to the key group by a lossless compression method to obtain a lossless compression code corresponding to the key group;

[0092] The key group code corresponding to the key group includes the s-order prediction coefficient corresponding to the key group and the lossless compression code corresponding to the key group.

[0093] Further, the forward group encoding unit 203 includes:

[0094] A first intra-group coding module is used for performing predictive coding on each forward group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the forward group and a residual sequence corresponding to the forward group;

[0095] a first inter-group coding module, configured to use a most recent key group preceding the forward group as a reference group of the forward group, obtain a residual sequence corresponding to the reference group, calculate a difference between a residual sequence corresponding to the reference group and a residual sequence corresponding to the forward group, obtain a difference sequence corresponding to the forward group, and compress the difference sequence corresponding to the forward group by a lossless compression method to obtain a lossless compression code corresponding to the forward group;

[0096] The forward group coding corresponding to the forward group includes the s-order prediction coefficient corresponding to the forward group and the lossless compression coding corresponding to the forward group.

[0097] Furthermore, the bidirectional group coding unit 204 includes:

[0098] A second intra-group coding module is used for performing predictive coding on each bidirectional group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the bidirectional group and a residual sequence corresponding to the bidirectional group;

[0099] A second inter-group coding module is used to determine the difference between the residual sequence corresponding to each of the key group and the nearest forward group on both sides of the bidirectional group and the residual sequence corresponding to the bidirectional group, obtain the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group, select the difference sequence with the smallest information entropy of the difference sequence between the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group as the difference sequence corresponding to the bidirectional group, and compress the difference sequence corresponding to the bidirectional group by a lossless compression method to obtain the lossless compression code corresponding to the bidirectional group;

[0100] The closest key group or the closest forward group corresponding to the difference sequence with the smallest information entropy is used as the reference group of the bidirectional group;

[0101] The bidirectional group code corresponding to the bidirectional group includes: an s-order prediction coefficient corresponding to the bidirectional group, a lossless compression code corresponding to the bidirectional group, and a sequence number of a reference group of the bidirectional group in the plurality of groups.

[0102] The embodiments of the present invention have the following technical effects: by adopting a bidirectional prediction coding and decoding method for telemetry code streams, the code rate is reduced through coding, and the saved code stream space is fully utilized to improve the bandwidth utilization of the transmission link. Specifically, the compression coding and decoding method combining grouping, inter-frame bidirectional prediction, and Huffman coding is used to improve the efficiency of the link.

[0103] On the other hand, an embodiment of the present invention provides a readable storage medium storing program codes corresponding to any one of the methods described above.

[0104] The embodiments of the present invention have the following technical effects: by adopting a bidirectional prediction coding and decoding method for telemetry code streams, the code rate is reduced through coding, and the saved code stream space is fully utilized to improve the bandwidth utilization of the transmission link. Specifically, the compression coding and decoding method combining grouping, inter-frame bidirectional prediction, and Huffman coding is used to improve the efficiency of the link.

[0105] The above technical solution of the embodiment of the present invention is described in detail below in conjunction with specific application examples. For technical details not introduced during the implementation process, please refer to the relevant description in the previous text.

[0106] In the aerospace measurement and control system, telemetry technology is needed to transmit various engineering parameters of the spacecraft, including position, speed, acceleration, engine working condition, video and audio signals on the rocket, to the ground measurement and control station through space-based or ground-based, wired and wireless methods. The telemetry data is sent to the data center or the launch mission contractor for processing through the network as the main transmission link through the measurement and control station. The original data format after passing through the ground measurement and control station is as follows: Figure 3 shown.

[0107] Figure 3 Each subframe contains 240 bytes, a full frame contains 64 subframes, and a subframe contains 8-bit time code + 240 bytes (subframe) data. The meaning of the data represented by each byte (subframe) can be set by the undertaker of the space launch mission. The subframe synchronization code is 0xEB90, and the subframe synchronization code is 0x146F.

[0108] The bidirectional predictive coding designed by the technical solution of the present invention is a compression process for subframe data. The coding process of a subframe data is now described.

[0109] like Figure 4 As shown, the original data is first grouped, each group contains p (equivalent to the first preset number) sampling values. Every k (equivalent to the second preset number) groups are marked as a key group, and every b (equivalent to the third preset number) groups between every two key groups are marked as a forward group. Except for the forward group, the groups between two key groups are all bidirectional groups;

[0110] The key group adopts the intra-group coding method (i.e., the first intra-group coding). Specifically, only the linear prediction coding LPC and Huffman coding are performed on its own data to calculate the s-order prediction coefficient (i.e., the s-order prediction coefficient corresponding to the key group) and the Huffman coding of the residual ck (the residual sequence corresponding to the key group) as the key group coding;

[0111] The forward group adopts the forward prediction coding method (i.e., the first inter-group coding). Specifically, the s-order prediction of the forward group itself (i.e., the s-order prediction coefficient corresponding to the forward group) and the prediction residual fk (i.e., the residual sequence corresponding to the forward group) are calculated, and the difference between the residual ck of the most recent key group before the forward group (i.e., the residual sequence corresponding to the key group) and the fk of the forward group (i.e., the residual sequence corresponding to the forward group) is calculated (equivalent to the difference sequence corresponding to the forward group), and the difference (equivalent to the difference sequence corresponding to the forward group) is Huffman coded to obtain the forward group coding.

[0112] like Figure 5 As shown, the bidirectional group calculates the s-order prediction coefficient (equivalent to the s-order prediction coefficient corresponding to the bidirectional group) and the residual dk (equivalent to the residual sequence corresponding to the bidirectional group) according to the linear prediction coding, compares the residuals of the key group and the forward group closest to the two-way group on both sides (that is, the residual sequences corresponding to the key group and the nearest forward group closest to the two-way group on both sides of the bidirectional group) with the difference with dk, and compares the difference with smaller difference information entropy for Huffman coding (that is, the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group is selected as the difference sequence corresponding to the bidirectional group, and the difference sequence corresponding to the bidirectional group is compressed by a lossless compression method to obtain the lossless compression code corresponding to the bidirectional group), which is composed of the s-order prediction coefficient of the bidirectional group itself to form the code of this bidirectional group.

[0113] The embodiments of the present invention have the following technical effects: by adopting a bidirectional prediction coding and decoding method for telemetry code streams, the code rate is reduced through coding, and the saved code stream space is fully utilized to improve the bandwidth utilization of the transmission link. Specifically, the compression coding and decoding method combining grouping, inter-frame bidirectional prediction, and Huffman coding is used to improve the efficiency of the link.

[0114] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0115] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0116] The disclosed embodiments are described above to enable any person skilled in the art to implement or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined herein may also be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0117] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including". In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

[0118] Those skilled in the art may also understand that the various illustrative logical blocks, units, and steps listed in the embodiments of the present invention may be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly demonstrate the interchangeability of hardware and software, the various illustrative components, units, and steps described above have generally described their functions. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art may use various methods to implement the described functions for each specific application, but such implementation should not be understood as exceeding the scope of protection of the embodiments of the present invention.

[0119] The various illustrative logic blocks or units described in the embodiments of the present invention can be implemented or operated by a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field programmable gate array or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, or any combination of the above. The general-purpose processor can be a microprocessor, and optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0120] The steps of the method or algorithm described in the embodiments of the present invention can be directly embedded in hardware, a software module executed by a processor, or a combination of the two. The software module can be stored in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or other storage media of any form in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Optionally, the storage medium can also be integrated into the processor. The processor and the storage medium can be arranged in an ASIC, and the ASIC can be arranged in a user terminal. Optionally, the processor and the storage medium can also be arranged in different components in the user terminal.

[0121] In one or more exemplary designs, the above functions described in the embodiments of the present invention can be implemented in hardware, software, firmware or any combination of the three. If implemented in software, these functions can be stored on a computer-readable medium, or transmitted in the form of one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media that facilitate the transfer of computer programs from one place to another. The storage medium can be any available medium that can be accessed by any general or special computer. For example, such computer-readable media can include but are not limited to RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store program codes in the form of instructions or data structures and other forms that can be read by general or special computers, or general or special processors. In addition, any connection can be appropriately defined as a computer-readable medium, for example, if the software is transmitted from a website site, server or other remote resource through a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wirelessly, such as infrared, wireless and microwave, it is also included in the defined computer-readable medium. The disk and disc include compact disk, laser disk, optical disk, DVD, floppy disk and blue-ray disk. Disks usually copy data magnetically, while discs usually copy data optically with lasers. The above combination can also be included in computer readable media.

[0122] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for bidirectional predictive coding of telemetry code stream for ground transmission, characterized in that: include: The original data is grouped into groups according to the sampling values ​​of each group being a first preset number, to obtain a plurality of groups, and a sequence number is set for each group in sequence; For all groups, a key group is marked every second preset number of groups, a forward group is marked every third preset number of groups between two adjacent key groups, and groups other than the forward group between two adjacent key groups are marked as bidirectional groups; For each key group, performing a first intra-group encoding on the key group to obtain a key group code corresponding to the key group; For each forward group, taking the most recent key group before the forward group as the reference group of the forward group, performing first inter-group coding on the forward group to obtain a forward group code corresponding to the forward group; For each bidirectional group, a group is selected from the nearest key group and the nearest forward group before and after the bidirectional group according to a preset condition as a reference group of the bidirectional group, and the forward group is subjected to a second inter-group coding according to the reference group of the bidirectional group to obtain a bidirectional group code corresponding to the bidirectional group; Arranging key group codes corresponding to all key groups, forward group codes corresponding to all forward groups, and bidirectional group codes corresponding to all bidirectional groups in the order of the key groups, the forward groups, and the bidirectional groups in the plurality of groups as the bidirectional predictive codes; The bidirectional predictive coding also includes the sequence number of the reference group corresponding to each bidirectional group in the plurality of groups; The raw data includes position, velocity, acceleration, engine operating conditions, and on-arrow video and audio signals; The bidirectional predictive coding method is based on Huffman coding compression; The method further comprises: for each bidirectional group, selecting a group from the nearest key group and the nearest forward group before and after the bidirectional group according to a preset condition as a reference group of the bidirectional group, and performing a second inter-group coding on the forward group according to the reference group of the bidirectional group to obtain a bidirectional group code corresponding to the bidirectional group, including: For each bidirectional group, predictively encode the bidirectional group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the bidirectional group and a residual sequence corresponding to the bidirectional group; Determine the difference between the residual sequence corresponding to each of the key group and the nearest forward group on both sides of the bidirectional group and the residual sequence corresponding to the bidirectional group, obtain the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group, select the difference sequence with the smallest information entropy between the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group as the difference sequence corresponding to the bidirectional group, and compress the difference sequence corresponding to the bidirectional group by a lossless compression method to obtain the lossless compression code corresponding to the bidirectional group; The closest key group or the closest forward group corresponding to the difference sequence with the smallest information entropy is used as the reference group of the bidirectional group; The bidirectional group code corresponding to the bidirectional group includes: an s-order prediction coefficient corresponding to the bidirectional group, a lossless compression code corresponding to the bidirectional group, and a sequence number of a reference group of the bidirectional group in the plurality of groups.

2. The method for bidirectional predictive coding of telemetry code stream for ground transmission according to claim 1, characterized in that: For each key group, performing first intra-group coding on the key group to obtain a key group code corresponding to the key group includes: For each key group, predictively encode the key group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the key group and a residual sequence corresponding to the key group, and compress the residual sequence corresponding to the key group by a lossless compression method to obtain a lossless compression code corresponding to the key group; The key group code corresponding to the key group includes the s-order prediction coefficient corresponding to the key group and the lossless compression code corresponding to the key group.

3. The method for bidirectional predictive coding of telemetry code stream for ground transmission according to claim 2, characterized in that: The step of performing first inter-group coding on each forward group by taking a key group immediately preceding the forward group as a reference group of the forward group to obtain a forward group code corresponding to the forward group includes: For each forward group, predictively encode the forward group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the forward group and a residual sequence corresponding to the forward group; Taking the most recent key group before the forward group as the reference group of the forward group, obtaining a residual sequence corresponding to the reference group, calculating the difference between the residual sequence corresponding to the reference group and the residual sequence corresponding to the forward group, obtaining a difference sequence corresponding to the forward group, and compressing the difference sequence corresponding to the forward group by a lossless compression method to obtain a lossless compression code corresponding to the forward group; The forward group coding corresponding to the forward group includes the s-order prediction coefficient corresponding to the forward group and the lossless compression coding corresponding to the forward group.

4. The method for bidirectional predictive coding of telemetry code stream for ground transmission according to claim 3, characterized in that: The lossless compression method includes Huffman coding.

5. A two-way predictive coding device for ground transmission of telemetry code stream, characterized in that: include: A grouping unit, used for grouping the original data into groups of sampling values ​​of a first preset number each, obtaining a plurality of groups, and setting a sequence number for each group in sequence; a marking unit, configured to mark a key group for every second preset number of groups for all groups, mark a forward group for every third preset number of groups between two adjacent key groups, and mark groups other than the forward group between two adjacent key groups as bidirectional groups; A key group encoding unit, configured to perform a first intra-group encoding on each key group to obtain a key group code corresponding to the key group; A forward group encoding unit, configured to, for each forward group, perform first inter-group encoding on the forward group by taking a key group immediately preceding the forward group as a reference group of the forward group to obtain a forward group code corresponding to the forward group; a bidirectional group encoding unit, configured to select, for each bidirectional group, a group from a nearest key group and a nearest forward group before and after the bidirectional group according to a preset condition as a reference group of the bidirectional group, and perform a second inter-group encoding on the forward group according to the reference group of the bidirectional group to obtain a bidirectional group code corresponding to the bidirectional group; a bidirectional prediction code acquisition unit, configured to arrange key group codes corresponding to all key groups, forward group codes corresponding to all forward groups, and bidirectional group codes corresponding to all bidirectional groups in the order of the key groups, the forward groups, and the bidirectional groups in the plurality of groups as the bidirectional prediction code; The bidirectional predictive coding also includes the sequence number of the reference group corresponding to each bidirectional group in the plurality of groups; The raw data includes position, velocity, acceleration, engine operating conditions, and on-arrow video and audio signals; The bidirectional predictive coding method is based on Huffman coding compression; The bidirectional group coding unit comprises: A second intra-group coding module is used for performing predictive coding on each bidirectional group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the bidirectional group and a residual sequence corresponding to the bidirectional group; A second inter-group coding module is used to determine the difference between the residual sequence corresponding to each of the key group and the nearest forward group on both sides of the bidirectional group and the residual sequence corresponding to the bidirectional group, obtain the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group, select the difference sequence with the smallest information entropy of the difference sequence between the difference sequence corresponding to the nearest key group and the difference sequence corresponding to the nearest forward group as the difference sequence corresponding to the bidirectional group, and compress the difference sequence corresponding to the bidirectional group by a lossless compression method to obtain the lossless compression code corresponding to the bidirectional group; The closest key group or the closest forward group corresponding to the difference sequence with the smallest information entropy is used as the reference group of the bidirectional group; The bidirectional group code corresponding to the bidirectional group includes: an s-order prediction coefficient corresponding to the bidirectional group, a lossless compression code corresponding to the bidirectional group, and a sequence number of a reference group of the bidirectional group in the plurality of groups.

6. The telemetry code stream ground transmission bidirectional predictive coding device as claimed in claim 5, characterized in that: The key group encoding unit is specifically configured to: for each key group, perform predictive encoding on the key group by a linear predictive encoding method to obtain an s-order prediction coefficient corresponding to the key group and a residual sequence corresponding to the key group, and compress the residual sequence corresponding to the key group by a lossless compression method to obtain a lossless compression code corresponding to the key group; The key group code corresponding to the key group includes the s-order prediction coefficient corresponding to the key group and the lossless compression code corresponding to the key group.

7. The telemetry code stream ground transmission bidirectional predictive coding device as claimed in claim 6, characterized in that: The forward group encoding unit comprises: A first intra-group coding module is used for performing predictive coding on each forward group by a linear predictive coding method to obtain an s-order prediction coefficient corresponding to the forward group and a residual sequence corresponding to the forward group; a first inter-group coding module, configured to use a most recent key group preceding the forward group as a reference group of the forward group, obtain a residual sequence corresponding to the reference group, calculate a difference between a residual sequence corresponding to the reference group and a residual sequence corresponding to the forward group, obtain a difference sequence corresponding to the forward group, and compress the difference sequence corresponding to the forward group by a lossless compression method to obtain a lossless compression code corresponding to the forward group; The forward group coding corresponding to the forward group includes the s-order prediction coefficient corresponding to the forward group and the lossless compression coding corresponding to the forward group.

8. A readable storage medium, characterized in that: It stores program codes corresponding to the method for implementing any one of claims 1-4.

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