WO1997015128A1

WO1997015128A1 - A system of fm data broadcasting and a method of processing data signals thereof

Info

Publication number: WO1997015128A1
Application number: PCT/CN1996/000089
Authority: WO
Inventors: Yalun Wang
Original assignee: Yalun Wang
Priority date: 1995-10-16
Filing date: 1996-10-16
Publication date: 1997-04-24
Also published as: CN1148297A; AU715471B2; EP0977388A1; JPH11513851A; AU7276696A

Abstract

A FM data broadcasting system comprising a transmitting section and a receiving section, input terminals, a stereo encoder and out terminals, the system is characterized in that the transmitting section further comprises a data transmitting unit, the first converting switch, the second converting switch, a mode controlling terminal; the receiving section further comprises a data receiving unit, a band-pass filter, a pilot identifier, the third converting switch, the system is compatible with the conventional FM broadcasting system and is effective to transmit data without any effectiveness on the reception of audio signals.

Description

FM data broadcasting and processing method thereof

~~ The present invention relates to a method for processing a data signal and a solution for compatibility in a conventional FM stereo broadcast compatible with data broadcasting. This data signal processing method can also be applied to other data transmission systems.

Background technique

~ "Language (speaking) and music are the two main components of sound broadcasting. For two-channel stereo broadcasting, the stereo effect of the audio broadcasting section EJ is of no practical significance. In existing stereo broadcasting, voice There is actually only one source for the program. This voice number is divided into left (L) and right (R) channels before transmission (the branch point X in Figure 1), and then transmitted using two channels, respectively. Listener's left and right ears. Obviously, if the voice signal is sent to the receiving end, as in the branching point Y in Figure 2, it is divided into left and right two channels, and the two listeners are distributed. The ear, the actual listening effect is exactly the same as the former, but it can save the transmission channel and transmission ability, and is used to transmit data signals for data broadcasting. This "mono + data" broadcast mode is suitable for stereo. Broadcasting period of all mono section 3 of the radio station.

Purpose of the invention

An object of the present invention is to enable an existing FM stereo broadcast system to have two-channel "stereo" and "mono + data" broadcast modes, which are compatible with each other and can be flexibly converted, thereby realizing Data broadcasting in FM stereo broadcasting.

Another object of the present invention is to enable existing FM stereo broadcast systems to have the capability of "chirping + low speed data" I "mono + high speed data" by encoding the data with an appropriate variable width code. The use of FM radio transmission potential.

Technical solutions

The system for performing FM L-R data broadcasting of the present invention comprises a transmitting portion and an accepting portion, the transmitting portion comprising: a "injecting end" having a left and right two channels L, R, a stereo encoder And a detecting end, the receiving part comprises a receiving end, a stereo decoder and a round out end; the transmitting part further comprises: a data transmitting part for providing a data signal to be transmitted; the first transfer switch KS1, disposed between the DSB-SC modulator, the data transmission part and the band pass filter; for selectively accepting the data signal or the audio signal; the second transfer switch KS2, disposed in the frequency divider and the narrow band filter For selectively switching on or off the pilot signal; a mode control terminal, connected to the first and second switches, KS1, KS2, for controlling the state of the switch, and the mode control terminal is also connected to the data transmission, And a data receiving part is configured to receive the transmitted data signal DT, Band-pass filter, which «Î¤ coupled into the receiving end terminal, for separating the baseband signal from the broadcast a data signal DT; a pilot identifier, whose turn-in is also connected to the receiving end, for identifying the pilot signal, and at the output terminal thereof, the mode control signal mode; a third transfer switch KR And being disposed between the band pass filter and the data receiving portion, and connected to the output end of the pilot identifier; wherein the mode control signal pulled by the pilot identifier passes through the third transfer switch The KR optionally sends the data signal DT to the data decoder for restoration to the transmitted data stream.

A method for processing a data signal for frequency-modulated L-R data broadcasting according to the present invention, the method comprising the steps of: a) setting a mode control signal mode of a mode control terminal in the transmitting portion; b) performing stereo broadcasting The mode control signal mode of the transmitting end stops the data transmitting portion from operating, and causes the stereo encoder to operate normally to obtain a baseband signal of the FM broadcast; c) when performing the FM L - R data broadcast, the transmitting The mode control signal mode of the terminal starts the data transmitting portion, disconnects the first transfer switch KS1 from the detection terminal DSB-SC of the DSB-SC modulator, and is connected to the data transmitting portion to transmit data, The second transfer switch KS2 is disconnected from the detection end of the frequency divider to cut off the pilot signal; d) a second band pass filter is provided at the receiving end to receive the transmitted broadcast baseband signal (including the data signal); e) A pilot identifier is provided at the receiving end for identifying the pilot signal from the baseband signal; f) a third transfer switch KR is provided between the band pass filter and the data receiving portion, The third transfer switch KR is connected to the detection of the pilot recognizer; g) when the pilot recognizer recognizes the pilot signal from the broadcast baseband signal, the mode control signal mode of the output terminal makes The third transfer switch KR is disconnected from the band pass filter, stops receiving the data signal, and causes the stereo decoder to operate normally, thereby obtaining a stereo broadcast signal; h) when the pilot recognizer is not from the «Γ When the pilot signal is identified in the incoming signal, the mode control signal at its rounding end causes the third transfer switch KR to be turned on with the band pass filter, thereby achieving reception of the data signal.

A system for transmitting data by using FM broadcasting, the system comprising a transmitting portion and a receiving portion, the transmitting portion comprising: a check-in end of two left and right channels L, R, and a stereo encoding And a «routend; the system is characterized in that: the transmitting part further comprises: a data transmitting part, the detecting is connected to the adder of the stereo encoder, and the first switching switch KS1 is disposed in the Between the band pass filter and the adder, for selectively receiving a low rate data signal or a high rate data signal; a second transfer switch KS2 disposed between the narrow band filter and the adder, The pilot signal is selectively turned on or off; a mode control terminal is connected to the first and second switches KS1 and KS2 for controlling a mode in which the data transmitting portion transmits the data signal; and the receiving portion further includes: The receiving portion is configured to receive the transmitted data signal DT; a low-speed bandpass filter whose inspecting terminal is connected to the receiving end for separating from the broadcast baseband signal a low-speed data signal; a high-speed band-pass filter having a check-in end connected to the receiving end for separating a high-speed data signal from a broadcast baseband signal; a pilot recognizer having a check-in end connected to the receiving end For identifying the pilot signal and rotating the mode control signal mode at its detection end; a third transfer switch KR, disposed between the high speed filter and the data receiving portion, and with the pilot The detection ends of the recognizers are connected.

A method of transmitting a data signal using an FM broadcast according to the present invention, the method comprising the following steps 泶: a) setting the mode control signal mode of the mode control end in the transmitting portion; b) when performing stereo broadcasting, the mode control signal mode of the transmitting end causes the first changeover switch KS1 to be closed, and the DSB-SC signal is sent to the superposition So that the data transmitting portion is in a low rate transmission state (eg, mode four); c) when the mono program is broadcast, the mode control signal mode of the transmitting end cuts the DSB-SC signal through the first changeover switch KS1, The pilot signal is cut off by the second changeover switch KS2, so that the data transmitting portion is in a high rate data transmission state (eg, mode six;); d) a high speed band pass filter is provided at the receiving end for receiving stereo broadcast a low rate data signal transmitted; e) a low speed band pass filter is provided at the receiving end for receiving a high rate data signal transmitted during mono broadcast; f) a pilot recognizer is provided at the receiving end for Identifying a pilot signal from a broadcast baseband signal; g) providing a third transfer switch KR between the high and low speed band pass filters and the data receiving portion, the third transfer switch KR The pilot identifier is connected; h) when the pilot identifier identifies the pilot signal from the broadcast baseband signal, the mode control signal mode of the output terminal passes the third transfer switch KR to enable the low speed filter Connected to the data receiving portion while the data receiving portion is in a low rate data receiving state; i) when the pilot recognizer does not recognize the pilot signal from the broadcast baseband signal, the mode control signal mode of the detecting end passes The third changeover switch KR connects the high speed filter to the data receiving portion while leaving the data receiving portion in a high rate data receiving state.

DRAWINGS

~~ The invention will be described in detail with the aid of the following figures, wherein

Figure 1 Propagation mode of speech signal in existing stereo broadcast

Figure 2 "Mono + Data" broadcast mode

Figure 3 Principle of FM "Stereo" / "Mono + Data" Broadcast

Figure 4 Stereo decoding principle

Fig. 5 Decoding principle of binary variable width code when Lmax = 1

Figure 6 How the waveform synthesizer works

Figure 7 FM "Stereo + Low Speed Data" / "Mono + High Speed Data" Broadcast Principle Figure 8 Signal and Spectrum of the Wide Code

Preferred embodiment of the invention

^ There are two possible ways to perform "mono + data" broadcasting in FM stereo broadcasting:

1) Directly use one channel in the stereo system to transmit the data signal; another channel to transmit the sound signal. The advantages of this method are as follows: 1. It can use existing stereo broadcasting and recording equipment to synchronously transmit and record sound and data signals; 2. Data signals can be used in different stereo broadcasting systems without conversion, such as frequency modulation and amplitude modulation. Transfer between and cable broadcast) and recording and playback devices. Its shortcomings are: 1. The existing FM radio and stereo recording and playback equipment must be equipped with a compatible circuit to automatically eliminate the noise of the data signal; 2. The utilization rate of the transmission channel is low.

2) Use the "left + right" channel (also known as L + R channel) of 0 w 15ΚΗζ to transmit the sound signal, and use the frequency band above 19ΚΗζ, such as the 23-53ΚΗζ "left-right" channel (also known as the L-R channel). ), The data signal is transmitted and the 19KHZ stereo pilot signal is turned off as a data broadcast marker. This kind of broadcasting mode is fully compatible with the existing FM radio, and has the characteristics of high data transmission rate and strong anti-interference ability of data signals. This vast way is called "FM L-R data broadcasting".

Figure 3 illustrates the operation of a "L-R data broadcast" compatible in an FM stereo broadcast system in accordance with the present invention. The broadcast transmitter needs to add a data processor 1, a "stereo" / "mono + data" broadcast mode selection control mode (mode), and add a pair of mode switch switches (KS1) in the conventional stereo coding circuit. , S2). At the broadcast receiving end, the data receiving portion is composed of a 23-53 kHz bandpass filter, a pilot recognizer, a mode switch (KR), and a data processor 2.

When performing stereo broadcasting, the mode signal of the transmitting end stops the data processor 1 and makes the stereo encoder work normally: the sum signal of the left and right sounds of the round (L, R) and the sum signal (L + R signal) using L + R channel transmission; their difference signal ( L - R signal) is used to suppress the carrier double sideband amplitude modulation (DSB-SC) for the 38KHz subcarrier, then use the L - R channel to transmit; After two-divided, a 19KH2 stereo pilot signal is obtained; these three signals are superimposed in the adder ( , ), and if necessary, the RDS and SCA signals are superimposed to obtain a normal FM broadcast baseband signal. The broadcast baseband signal is transmitted by the transmitter and restored by the receiver's discriminator. At the receiving end, the pilot signal in the broadcast baseband signal sets the pilot recognizer. The detection of the pilot recognizer (mode) cuts off the check-in of the data processor 2 through the switch KR, causing the data processor 2 to stop operating. The pilot signal in the broadcast baseband signal makes the stereo decoding work normally. Figure 4 shows its working principle: The pilot signal is separated from the baseband signal by a 19KHz narrowband filter; after the pilot signal is doubled, it is restored to 38KHz. The carrier is multiplied (demodulated) with the DSB-SC signal in the 23-53KHz band, and the product signal is restored by a low-pass filtering of 0 w i5KHz to restore the L-R signal; The L-R signal is added and subtracted from the L + R signal in the L + R channel to obtain the detected signals ( L , R ) of the left and right sounds, respectively.

When FM L-R data is broadcast, the sound signal (L + R signal) is still transmitted using the L + R channel. Under the control of the transmitter mode signal, the data processor 1 converts the data stream into a data signal (DT); the KS1 switch cuts off the DSB-SC signal in the stereo encoder, and passes the DT signal through the 23 w 53 KHz bandpass. The filter is fed into the adder ( , ); the KS2 switch cuts off the 19KHz pilot signal. At this time, the broadcast baseband signal contains a sound signal of 0 w i5 KHz and a data signal of 23 w 53 KHz, and there is no stereo pilot signal. At the receiving end, the data signal DT is separated from the broadcast baseband signal by a bandpass filter of 23 w 53 KHz. Since there is no pilot signal in the broadcast baseband signal, the pilot recognizer is zeroed. The pilot of the pilot recognizer sends the data signal DT to the data processor 2 through the KR switch, and the restored data stream is data. At this time, in the stereo decoder, since there is no 19KHz pilot signal in the broadcast baseband signal, the 38KHz subcarrier cannot be multiplied. Thus, after the multiplier (X), the data signal remains in the original 23 w 53 Hz signal, which will be filtered by the subsequent audio filter circuit. At this time, the L - R signal is zero, and it adds and subtracts the result from the L + R signal, so that the two channels of the stereo decoder are both L + R letters. The sound signal in the road. That is to say, the L + R signal at this time is divided into left and right channels in the stereo decoder.

Therefore, when performing FM L-R data broadcasting, using an ordinary FM radio, whether stereo or mono, people can hear the sound signals in the L + R channel, and can only hear the sound signals in the L + R channel. Not the data signal in the L-R channel. Once the pilot signal is present in the FM broadcast, the stereo decoder returns to normal stereo decoding and the data processor 2 stops the data demodulation. This is the principle that "FM L _ R Data Broadcast" is compatible with the current "FM Stereo Broadcast". The "pilot indication" signal from the stereo decoder can also be used as the mode control signal (mode) at the receiving end.

The broadcast mode can be checked in by the mode of the transmitter, or it can be controlled automatically by a signal comparator. The principle is: Compare the two-way sound intrusion signals. When the L and R sounds are the same (L - R - 0 ), the necessary program is started, and the selection of the broadcast mode is made.

When broadcasting is broadcast, the audio output (L, R) of the receiving device of the relay station is directly connected to the audio check-in end (L, R) of the transmitting device, and the mode of the receiving device is “mode” that is directly connected to the transmitting device. In. When the data broadcast is broadcast, the repeater does not need the data processor 1 and the data processor 2 to directly connect the DT of the receiving device to the DT «T input of the transmitting device. The relay station can also change the content of the data broadcast. At this time, a data processor is needed between the data output of the receiving device and the data wheel of the transmitting device to modify the content of the data stream.

When stereo broadcasting is performed, the pilot signal may be "lost" due to interference, and the DSB-SC signal in the L-R channel may be misinterpreted as a data signal. Therefore, the transmitted data should have some error detection capability. Data Processor 2 - Once it finds the wrong data, it gives up.

The key to realizing FM L-R data broadcasting is: 1. To make the effective spectrum of the data signal all concentrated in the band of 23 "53KHz; 2. The interference of the data signal to the adjacent channel must meet the requirements of the broadcasting standard, especially The noise of the sound signal must be less than -60dB, and it will not trigger the frequency multiplier circuit in the stereo decoder. The effective spectrum is the frequency component necessary to recover the data signal with certain anti-interference ability, and the frequency band of the effective frequency is called Is the effective frequency band.

The present invention employs a pattern that conveys digital information in discrete values of symbol width, referred to as a variable width code. The waveform of the variable width code is a bipolar non-return-to-zero pulse signal. Each pulse element is one symbol. The difference in pulse width indicates different information, pulse polarity, amplitude, pulse edge and other geometrics. The parameter does not carry information. The symbol width of the variable width code may have two scales or two or more discrete values to form a binary or multivariate variable width code. The invention divides the symbols of the variable width code into two categories, wherein one symbol with the shortest code width is called S code, the code sympleced for continuous S code is called "S" code string, and the value of TS represents S code. The symbol period; the remaining types of widened symbols are collectively referred to as L codes, the code strings consecutively L codes are referred to as "L" code strings, and the value of TL represents the symbol period of the L code having the longest pulse width. The L code in the multivariate variable width code has more than one symbol period. The symbol period of the variable width code is different. Here, the reciprocal of the symbol period of the S code is called the symbol rate of the variable width code, and its value is B = 1 / TS; the widest L code and S code are used. Symbol week The ratio of the period is called the pulse width ratio K ( K = TL: TS ) of the variable width code. The symbol rate (B) and the pulse width ratio (K) are hard parameters that affect the effective band of the widened code.

The characteristic of the widened code frequency is: when the forest width ratio K ≤ 3 of the widened code, its effective frequency band is distributed on both sides of 0.5 ;; when the continuous "S" code string in the data stream becomes longer , the effective frequency is close to 0.5 ;; when the continuous "L" code string in the data stream becomes longer, its effective frequency spreads to the sides; changing the pulse width ratio of the variable width code will also Change its effective frequency band.

From this, it can be concluded that: 1. The length of the "L" code string of the variable width code is controlled within a certain range so that it is not greater than Lmax (Lmax is called the maximum code number of the L code), then it can be The effective spectrum is controlled within a certain frequency band, and lowering the value of Lmax can narrow its effective frequency band. 2. Control the length of the "S" code string of the widened code within a certain range so that it is not less than Smin (Smin is called the minimum number of consecutive codes of S code), then increasing the value of Smin can also make the width wider. The effective frequency band of the code is narrowed. Therefore, Lmax and Smin are soft parameters of the effective band of the variable width code.

The lower limit (Fdn) and upper limit (Fup) of the effective band of the binary variable code are respectively

Smin + Lmax + 1

Fdn = B; (1.1)

2 [(Lmax + 1) Κ + Smin]

Smin + 3 x (Lmax + 1)

Fup = x B (1.2)

2 x [(Lmax + 1) K + Smin]

When the bandwidth of the channel satisfies or is greater than Fdn Fup, the pulse width and geometry between the S code and the L code after the transmission of T have sufficient feature differences for waveform identification and differentiation. When the channel band does not satisfy Fdn Fup, the difference will be sharply reduced, and the anti-interference performance of the widened code signal will drop sharply. Available from 1.1 and 1.2 [(Lmax + 1) K + Sminj

(2.1)

Smin + Lmax + 1

2 [(Lmax + 1) Κ + Smin]

Β = Fup. (2.1)

Smin + 3 (Lmax + 1)

Fdn Smin + Lmax + 1

= (3.0) Fup Smin + 3 χ (Lmax + 1)

From this, the parameters Lmax, Smin and K are the main factors determining the spectrum, anti-jamming performance and data transmission rate of the widened code. The definition of the pattern of the variable width code consists of the following three parts: Starting with the letter L, the subsequent number indicates the value of Lmax, if Lmax is infinite, it is represented as LX; Starting with the letter S, the subsequent number indicates the value of Smin; The beginning of the letter K, the subsequent number (including the decimal point) represents the value of K. For example, the "LXS1 2.5" code indicates a widened code with Lmax at infinity, Smin = 1 and K = 2.5, and the "L1S2" code indicates Lmax = 1, Smin = 2, and the K value is undefined.

As can be seen from Equation 3.0, Fup: Fdn = 3 for the "LXS1" pattern (ie Lmax is infinity, Smin = 1) and the width of the effective band of the signal (Fup - Fdn) = 2 X Fdn. Therefore, when the channel bandwidth is greater than or equal to 2 X Fdn and the binary information is transmitted, each "1" character in the binary information can be directly converted into an L code, and each "0" character is converted into an S code; Or convert each "0" character into an L code and convert each "1" character into an S code. This scale conversion is called "direct coding".

When the channel bandwidth is less than 2 X Fdn, the effective band of the variable width code can be first compressed by limiting Lmax and Smin = 1. For example, when using the "L1S1" widened code, Fdn: Fup = 3/7, the required channel bandwidth is 4 3 X Fdn. When the channel bandwidth is less than 4/3 X Fdn, the Smin value can be increased to further compress the effective frequency band of the widened code signal.

When the value of Lmax is not equal to infinity, the coding principle when widening the code wheel digital information is: Each piece of information consisting of the same kind of cell (information unit) is a "group", in each "group" Before the message, a cell class is first assigned to define the cell type of the "group" information, and then information indicating the length of the "group" is transmitted. The class of a cell is a specific code string consisting of an L code and an appropriate S code if necessary. Behind the type character, each S code represents a cell defined by this type character until the next type character appears.

When the value of Lmax is not equal to infinity, the decoding principle of the variable width code is to determine the type of the cell to be delivered by identifying the cell type character in the data stream, and then convert each subsequent S code into A determined cell until the next type character appears.

When the information stream composed of N kinds of cells is transmitted by the binary variable width code, if the cell type is simply represented by the length of the "L" code string, the Lmax of the binary variable width code is N; if L is used The different arrangement of the code and the S code indicates the cell type, or a suitable protocol, which may result in Lmax < N. Therefore, after the N-ary digital information is converted into a binary variable width code, Lmax < N, thereby achieving the purpose of controlling the effective frequency band of the data signal.

The different expressions of the type characters constitute different encoding methods of the variable width code. The purpose of selecting different encoding methods is to change the pattern soft parameters Lmax and Smin, thereby changing the effective frequency band of the variable width code.

When binary binary code is used to pass binary information consisting of " 0 "" 1 " characters, there are two basic encoding methods (ie, Smin = 1): A basic encoding method: Let Lmax = 2, then the widened code has two different lengths of "L" code strings, which can be used as the type characters of "0" and "1" characters, respectively.

For example, the L code of the sheep indicates the character type "0", and the character L "1" is represented by two consecutive L codes. At this time, the encoding process of the A mode is: When a "0" string (including a single "0" character) appears in the data stream, the encoder first extracts an L code, and then sets this "0" string. Each character in the "0" is converted into an S code; when a "1" string (including a single "1" character) appears in the data stream, the encoder first checks out two L codes, and then connects the one. Each character "1" in the "1" string is converted into an S code; the decoding process of the A mode is: When a single L code appears in the data stream of the variable width code, each S after the L code is used. The code is converted into a "0" character until the next L code appears; when two consecutive L codes appear in the widened code data stream, each S code following the two L codes is converted into a "1" " character until the next L code appears;

Of course, it is also possible to represent the character type "1" with a single L code and the character type "0" with two consecutive L codes.

B basic coding method: In order to compress the effective frequency band of the variable width code, Lmax = 1 can be obtained. At this time, the variable width code has only one type of "L" code string (ie, a single L code). Using this type of "L" code string does not indicate the specific type of cell, but it can mean "the cell type has changed". For example, when an L code appears, if the character "0" is transmitted before this, then the character "1" is transmitted from then on; if the character "1" is transmitted before then, it is transmitted from then on. This is the character "0". Therefore, as long as the initial state of the receiver decoder can be correctly defined, or the operating state of the decoder is adjusted (set) in time to match the state of the transmitter encoder, the decoder can correctly restore the decoder. Binary digital information, otherwise the translated binary information will appear "0" "1". This "0" "1" phenomenon is called the polarity of binary digital information. The state setting of the decoder is called polarity synchronization of binary digital information.

A binary variable code with Lmax = 1 cannot define the state of the decoder. The invention further enables the binary digital information to carry its own polarity information, so that the polarity reversal phenomenon can be found and corrected during the decoding process of the receiving end.

The principle of polarity synchronization of binary digital information is: Set a "polar sync". For example, a string of " 1 " with a length of k is used as the polarity synchronism, that is, the string "011... -- 110" (where the number of " 1 " is equal to k ). Then the polarity synchroniser is in the form of a string when the class is inverted, that is, the string "100... 00 (where the number of "0" is k), which is called the "synchronized reflection" of the polarity. get on:

1) "Add 1" processing: When a "1" string with a length greater than or equal to k appears in the data stream, add a character "1" to the "1" string. There is no polarity synchronism in the processed data stream.

- X - 2) "Add 0" processing: When a "0" string with a length greater than or equal to k appears in the data stream, add a character "0" to the "0" string. There is no synchronous reflection in the numbered stream after this processing.

3) "Add synchronization" processing: In the data stream after "add 1" and "add 0", every suitable distance, or divide the data into "blocks", insert appropriate blocks between blocks The polarity of the number is synchronized.

In the binary digital information stream processed by these three steps, once the synchronous feed symbol appears, it means that the polarity is inverted. In this case, the "0" and "1" in the data are inverted, which is the correct binary information.

The data broadcast should adopt the "data packet" inspection method. At this time, the separator of the data packet can be used as the polarity synchronization character, and the character form in which the separator is reversed is the synchronous reflection character. Therefore, in the original data packing process, the "plus 0" process is added, and in the original data unpacking process, the character polarity synchronization and the "minus 0" process are added, and the binary variable width code of Lmax = 1 can be used. Check binary digital information.

The header and trailer of the data block should be preceded by a "header" and a "tailer" to avoid the combination of the separator and the transmitted data, and generate a (pseudo) string similar to the separator and sync inverse. . The header and the end of the package can be in the form of multiple scales. For example, the first character of the header and the last character of the trailer are "1". Other characters can be used to pass the length, attributes, and Additional information such as error detection and correction provides multiple "parallel virtual channels" for the user layer. The end of the package also acts to clean up the encoder and decoder registers. The data block should be "added 1" and "plus 0" along with its header and end of the packet, and then connected to the polarity synchronizer.

The encoding process of the B mode is: dividing the data to be transmitted into data blocks. A header and an end of the packet are placed at the front end and the back end of each data block, and then "add 1" and "plus 0" are processed to form a data packet. Insert an appropriate amount of separator between the packet and the packet and reconnect it. Then convert each character in the stream (whether it is "0" or "1") into an S code, and change the character from "0" to "1" or "1". In the place of "0", insert an L code.

Figure 5 shows the principle and process of decoding, polarity synchronization and unpacking of the B mode: The initial state of the character register in the decoder ("0" or "1") can be arbitrarily set. When the variable code data stream is sent to the decoder, if an S code is rounded, the decoder detects the character in a character register; if an L code is checked in, the character polarity in the character register When the class is inverted, the decoder does not detect any characters. The data stream detected by the decoder passes through the polarity adjuster. The polarity regulator also has a state control check-in whose status control signal is detected from the status register. The initial state of the status register checkout can be arbitrarily set. When the status control signal is "0", the data stream remains in its original polarity after passing through the polarity adjuster; when the status control signal is "1", the character polarity is reversed after the data stream passes through the polarity adjuster. The data output by the polarity regulator is temporarily stored in the data register. In the same time, a sync device consisting of 'k + 2, bit shift register is also sent. When a synchromorph appears in the sync discriminator, its output causes the state in the status register to be reversed once, and the data temporarily stored in the data register is discarded, causing the stack pointer of the data register to move back to the starting point. When a separator (that is, a polarity synchronizer) appears in the sync discriminator, the data in the data register must be processed once. If the data of the temporary storage is greater than a certain value at this time, the data of the temporary storage device is a valid data package, which can be sent to the unpacking device for unpacking processing; otherwise, the data in the temporary storage S is invalid. Give it up. Regardless of whether the data in the scratchpad is valid, the stack pointer of the data register should be moved back to the starting point after each processing. The data is processed in the unpacker by "minus 1" and "minus 0". "Less

1 " Processing is, when there is a "1" string greater than k in the data stream, a character "1" is left from the string. "Subtract 0" The process is when the data stream has a connection greater than k. When the string is " 0 ", a character " 0 " is removed from the state of the string. Then the header and the end of the packet are removed, which is the transmitted data block. The restored data block is connected. The transmitted binary digital information is obtained. In order to complete the character polarity error correction synchronization process described above, an appropriate amount of separator is inserted between the data packets.

The Miller code consists of three different width symbols, and the code width ratio between them is 2:3:4, which are called M2 ^, M3 code and M4 code. The two basic encoding methods (ie, Smin = 1) when transmitting the Miller code information using the binary variable width code are:

C basic coding mode: When Lmax = 3, the widened code has three different lengths of "L" code strings, which can be used as the type symbols of the three symbols of the Miller code.

For example, the M2 symbol has the highest usage rate, and a single L code is used as the type symbol of the M2 code, and a "L" code string of length 2 is used as the type symbol of the M3 code, and a "L" code of length 3 is used. The string is a type character of the IM4 code. At this time, the encoding process of the C mode is: When a "M2" code string (including a single M2 code) appears in the Miller code data stream, the encoder first extracts an L code, and then connects the "M2" code string. Each M2 symbol in the MZ symbol is converted into an S code; when a "M3" code string (including a single M3 code) appears in the Miller code data stream, the encoder first rotates two L codes first, and then this Even each M3 symbol in the "IVI3" code string is converted into an S code; when there are even α Μ 4 " code strings in the Miller code stream (including the Μ 4 code of the sheep), the encoder first detects three consecutive codes. The L code then converts each Μ4 symbol in the ^u4码 code string into an S code. At this time, the decoding process of the C mode is: when a single L code appears in the data stream of the variable width code, each S code following it is converted into a Μ2 code until the next L code appears; When two consecutive L codes appear in the data stream, each S code following it is converted into a Μ3 code until the next L code appears; when three consecutive L codes appear in the variable code data stream, Convert each S code following it to a Μ4 code until the next L code appears.

D basic coding method: In order to compress the effective frequency band of the variable width code, Lmax = 2 can be obtained. At this time, two or more L codes suitable for the S code can be used to form three different types of code strings as the type symbols of the three Miller code symbols. For example, use an L code followed by an S code (represented as "L + S" code string) as the class 3⁄4 of the M2 code; use two consecutive L codes (represented as "L + L" code strings) as M3 The type of the code; an L code followed by an S code followed by an L code (represented as "L + S + L " code string) as the type of the M4 code. At this time, the encoding process of the D mode is: When a "M2" code string (including the M2 code of the sheep) appears in the Miller code data stream, the encoder first extracts an "L + T" code string, and then puts this Each M2 symbol in the "M2" code string is converted into an S code; when a "M3" code string (including a single M3 code) appears in the Miller code data stream, the code S first rotates an "L" + L "code string, then convert each M3 code in the "M3" code string into an S code; when a "M4" code string (including a single M4 code) appears in the Miller code data stream, The decoder first detects an "L + S + L" code string and then converts each M4 symbol in the "M4" code string into an S code. At this time, the decoding process of the D mode is: When the "L + S + S" code string appearing in the data stream of the widened code, the decoder first detects an M2 symbol, and then converts each subsequent S code. Form an M2 code until the next L code appears; when the "L + L" code string appears in the data stream of the variable width code, convert each subsequent S code into an M3 code until the next L code appears. When the "L + S + L " code string appears in the variable code data stream, each subsequent S code is converted into an M4 code until the next L code appears.

Due to the addition of a type character in the encoding process, the amount of data passed is expanded. On the other hand, in the process of transmitting the Miller code information, when the symbol period of the M2 code is equal to TS, TS = 2 A, the specific transmission of the M3 code with a period of 3 Δ and the M4 code with a period of 4 Δ Time only used 2 Δ. That is to say, the data amount of the Miller code is compressed after the variable width code is encoded, and the instantaneous maximum value of this compression ratio can be 2:1. After comprehensively expanding and compressing the two effects, the coding efficiency η of the variable width code (n is equal to the ratio of the amount of data before encoding to the amount of data after encoding) is related to the parameters of the variable width code, the encoding method, and the structure of the data stream. A dynamic value. If the encoding/decoding process of the variable width code is regarded as one of the components of the "passing wheel", then the transmission rate of the "user" data is equal to Β η , which is also a dynamic value. When the pulse width ratio of the variable width code is equal to 2, the coding efficiency of the basic coding method is 0.333 < η < 1, and the statistical average is about 0.711; the coding efficiency of the D basic coding method is 0.283 < η < 2, statistical average The value is about 0.730

On the basis of the basic coding mode of the variable width code, Smin > 1, the external frequency band of the variable width code can be further compressed or its anti-interference ability can be improved. At this time, the coding efficiency decreases as the Smin value increases.

The principle of the variable width code encoding when Smin > 1 is that (Smin - 1) S codes are added after each class 3⁄4 character, and then the cells are transmitted. At this time, the decoding principle of the widened code is to skip (Smin - 1) S codes after each type character, and then convert the subsequent S code into the cell defined by the type symbol until the next L The code appears.

The encoded variable-width code signal still contains a very rich low-frequency and high-frequency harmonic components, which cannot be directly sent to the transmission channel, and must be very strictly filtered to meet the requirements of the broadcasting technology standard, for example. , the nuisance to the sound channel must be less than - 60dB, and will not burst stereo decoding The carrier is restored in the carrier. Such filtering effects are difficult to achieve using hardware circuits or digital filters.

The waveform synthesizer employed in the present invention is a "code/pulse element" converter that determines the shape of the snatch pulse element based on the code form of the wheeled variable code data stream. The shape of these pulse elements is a set of pre-optimized waveform blocks. The trick of this optimization process is to make the spectral distribution of the signals spliced by these waveform modules meet specific requirements.

Figure 6 is a block diagram of the waveform synthesis: The symbol window is a shift register of a variable length code symbol of appropriate length. Predetermine the code string form of all possible variable width codes in the symbol window, called code strings, and store them in the "code" area of the "module library". And in advance, these code strings are replaced by some original waveform one by one, for example, a variable amplitude rectangular wave having the same area of the pulse element; or further, the rising edge of the buffer is a sinusoidal curve falling from a negative 90 degrees to a positive 90 degree. A sinusoidal sine wave with a range of positive 90 degrees to minus 90 degrees, and then find the ideal waveform after passing through the ideal filter. Then each code string corresponds to an ideal waveform. The pulse element located at the center of the ideal waveform is a waveform module, which is the mark of the symbol at the center of the code string. The quantized value of each waveform module is stored as an array in the "module" area of the "module library". Through this "module library", the "code" is associated with its corresponding "module" one-to-one. This is the pre-optimization process. When the data is transmitted, the data stream of the variable width code is shifted through the symbol window. After each shift, the code string appearing in the symbol window is taken as the search basis. The corresponding code string is found in the code area of the module library. The corresponding waveform module is found through the code string, and then the waveform module is used. Group value) is fed into the digital/analog (D / A) converter. Driven by the sampling clock, and converted according to the principle of alternating positive and negative polarity, this set of values is converted into a pulse element waveform by the D / A converter. After a mark waveform is generated, the data stream is shifted by one bit in the symbol window, and then the next mark waveform is synthesized. This waveform synthesis process is performed by a computerized D/A conversion device.

After the digital signal is clipped and amplified, the pulse width is adjusted to restore the variable width code. Directly using the zero-crossing method, the system's anti-interference performance is not high, because the harmonic components of the widened code signal are filtered out, the waveform is distorted. The symbol recognizer used in the present invention integrates the amplitude-amplified variable-width code signal, and then obtains the time period tx of the integral value crossing zero. When tx is greater than the cycle threshold tm, it is judged as an L code, otherwise it is judged as an S code. Adjusting the period threshold tm and the splitting time constant 敖 tr can make the symbol recognizer in the best working condition. It can identify the heavily deformed variable width code and greatly improve the anti-interference performance of the data receiver. In the FM broadcast, the application of the variable width code can flexibly constitute a plurality of data broadcast modes, for example: Mode 1: When the "L1S1" code type and the B code type are adopted, the effective frequency band of the widened code signal is

22.714 - 53KHz „ basically coincides with the current L-R channel. At this time, if K or the like is 2 or 2.5, the data rates are about 53.8Kbps and 64.6Kbps respectively. Mode 2: With the "L1S25" pattern and B coding method, the effective frequency band of the widened code signal is 53.069 w 60.931 KHz, which is in agreement with the current RDS channel (57±4KHz). At this time, if K or the like is 2 or 2.5, the data rates are approximately 18.2 Kbps and 18.5 Kbps, respectively. Appropriately increasing the Smin value and lowering the data rate can improve the anti-interference performance of the data signal and increase the isolation between the RDS and the adjacent channel. The use of variable width code technology for data broadcasting in the RDS channel has the advantages of high data rate, simple receiving circuit and reliable system compared with ASK or PSK.

Mode 3: There is no standard for the upper limit of the frequency band of the frequency band above 61KHz (called the SCA auxiliary communication channel) and the use of the SCA channel in the FM broadcast baseband signal. If the "L1S16" pattern and the B-encoding method are adopted, the effective bandwidth of the variable-width code signal is 61.2 74.8KHz, and data broadcasting can be performed in the 61-75KK SCA channel. At this time, if K is equal to 2 or 2.5, the data rate is about 30.5Kbps and 31.3Kbps respectively.

Mode 4: The RDS channel and the SCA channel are combined as a data channel with a bandwidth of 53 75 KHz. Data broadcasting can be performed using the "L1S8" pattern and B encoding. At this time, if K or the like is 2 or 2.5, the data rates are about 42.2 Kbps and 44.0 Kbps, respectively.

Although the coding efficiency of the B basic coding method is higher than that of the direct coding (about 36.3 %), it is a correlation code. When a symbol is interfered and a bit error occurs, this bit error may affect subsequent symbols. The plague of this scale error does not cross the packet separator, affecting the next packet. In contrast, errors in the direct encoding method do not affect other symbols.

Mode 5: Extend the data channel to 20 w 60 Hz (ie L-R channel plus RDS channel, SCA channel is not affected), or expand to 23 w 69 KHz, or 23 w 75 KHz, or use a higher frequency upper limit, Data broadcasting can be performed using the "LXS1" type wideband code and direct encoding. The probability of the "0" and "1" symbols in the information stream is equal, K = 2, the data rate of the broadcast can reach 53.3Kbps, 61.7Kbps, 66.7Kbps or higher, and the anti-interference ability of the signal can reach 23 to 16dB.

Mode 6: The pulse width ratio of "L1S1" is 1:2.0: 2.5: 3.0 quaternary width code, such as the pulse width TS = 2 Δ of the S code, the code widths of the three L codes are 4△, 5 respectively Δ, 6 Δ, which are called Τ4, Τ5, Τ6 codes, respectively, the effective band of this variable width code is exactly 22.928 w 75 ΚΗζ. After converting the binary information into the Miller code, the quaternary direct coding method is adopted, for example, a single Τ4 symbol is used as the 类型2 code cell type symbol; a single Τ5 symbol is used as the Μ3 code cell type symbol; The Τ6 symbol is used as the 类型4 code cell type symbol, and then each S symbol represents a defined Miller code symbol. At this time, the symbol rate Β is 107.142 ΚΗζ, and the data rate is much higher than the above several application modes. The above data broadcasting modes 1, mode 2, mode 3 and mode 4 are in line with the current FM broadcasting standards. Data broadcast mode 5 and mode 6 have the characteristics of high data rate, strong anti-interference performance, and stable system (small bit error). Data broadcasts in Mode 1, Mode 5, and Mode 6 are all interrupted by the broadcast of the stereo. An FM radio station can simultaneously sample multiple data broadcast modes, data

- Β - The corresponding data receiving part is prepared in the receiver, and the received data stream is mixed and formed into a computer. When the effective frequency band of one of the data broadcast modes conflicts with the stereo signal, the data transmission and reception of the mode is controlled by a mode control signal (mode).

When the FM radio broadcasts the stereo program, the mode control signal mode of the transmitting end sends the DSB-SC signal to the adder through the KS1 switch, and the pilot signal is sent to the full adder through the KS2 switch, and the data transmitting part is at the low rate data transmission. Status, such as mode four. At this time, the receiving terminal pilot recognizes that the detected mode control signal mode passes the KR switch to make the low speed band pass filter S open to the data receiving portion, and the data receiving portion is in the low rate decoding working state. When the FM radio broadcasts the mono program, the mode control signal mode of the transmitting end cuts off the DSB-SC signal through KS1, cuts off the pilot signal through the KS2 switch, and causes the data transmitting part to be in a high-rate data transmission state, such as mode 6. At this time, the mode control signal mode of the receiving end enables the high-speed band-pass filter to be connected to the data receiving portion through the KR switch, and the data receiving portion is in a high-rate decoding operation state. The variable width code and waveform synthesis techniques can also be applied to other frequency bands of the broadcast, as well as other data communication channels.

The upper graph of Fig. 8 is a signal wave of a binary variable width code of a symbol window width such as 15 , Lmax = 1 , Smin = l , pulse width ratio, etc. The following figure is a frequency diagram of the variable width code.

Claims

Rights request

1. A scale device for utilizing an L-R channel broadcast data in an FM broadcast transmission system, the FM L-R channel comprising a subtractor for receiving a «input signal, a DSB-SC modulator, a band pass A filter and an adder, the device characterized in that the device further comprises:

a data transmitting portion whose check-in end is connected to a data interface (data) for providing a data signal to be transmitted;

a first transfer switch (KS1) disposed between the DSB-SC modulator, a data transmitting portion, and a band pass filter for selectively receiving a data signal or an audio signal;

a second transfer switch (KS2) disposed between the frequency divider and the narrow band filter for selectively turning on or off the pilot signal;

a mode control terminal is connected to the first and second switches (KS1, KS2) for controlling the state of the switch, and the mode control terminal is also connected to the data transmitting portion for controlling the data transmitting portion to send the data signal

2. The apparatus according to claim 1, further comprising a comparator whose input ends are respectively connected to the left and right channels for comparing the similarities and differences of the left and right channel channels, and the detecting end and the mode control thereof. Connected to the end, used to automatically control the operation of the switch (KS1, KS2) and the number 6 transmission part.

The apparatus according to claim 1, wherein said mode control terminal controls the operations of said first and second switches (KS1, KS2) and the data transmitting portion by manual control.

4. The apparatus of claim 1, wherein the data transmitting portion further comprises a data encoder for encoding the intruded data and providing the encoded data to the data transmitting end.

5. The apparatus according to claim 1, further comprising a data signal (DT) connected to said first transfer switch (KS1) for directly rebroadcasting a data signal terminal (DT) of the receiving portion. Data signal.

6. The apparatus of claim 1, wherein a data processor is provided between the data interface of the receiving portion and the data interface of the transmitting portion during the rebroadcast for modifying the content of the data stream.

7. The apparatus of claim 1, wherein the mode control mode is directly connectable to a mode control terminal of the receiving end for rebroadcast mode control signals when rebroadcasting.

8. The apparatus according to claim 4, wherein said data encoder uses a variable width code to concentrate the effective frequency of the data signal in a desired frequency band, said variable width code being characterized by a code The discrete value of the element width conveys digital information, which is a bipolar non-return-to-zero pulse signal, each of which is a symbol, and the different widths of the pulses represent different information.

9. The apparatus according to claim 4, wherein said data transmitting portion further comprises a waveform synthesizer for waveform synthesizing the encoded data of the data encoder «supplied so that the interference of the data signal to the adjacent channel satisfies the broadcast Standard requirements.

10. Apparatus according to claim 9 wherein said waveform synthesizer is a "code/pulse element" converter for determining the shape of the chirped pulse element based on the code form of the intrusion data stream.

11. Apparatus according to claim 10 wherein the shape of the pulse element is pre-optimized.

12. Apparatus for receiving broadcast data of an L-R channel in an FM broadcast system, the apparatus comprising a receiving end, a stereo decoder, and a detecting end, wherein the apparatus further comprises: a data receiving portion, configured to receive the transmitted data signal (DT);

a band pass filter whose «input terminal is connected to the receiving end for separating the data signal (DT) from the broadcast baseband signal;

a pilot identifier, the rush end of which is also connected to the receiving end for identifying a pilot signal and detecting a mode control signal (mode) at its output;

a third transfer switch (KR) disposed between the band pass filter and the data receiving portion and connected to the detection end of the pilot recognizer;

The mode control signal detected by the pilot recognizer selectively transmits the data signal (DT) to the data receiving portion through the third transfer switch (KR) to be restored to the transmitted data stream.

13. Apparatus according to claim 12 wherein said data receiving portion includes a limiting amplifier. A symbol recognizer and a data decoder for limiting the received wide coded encoded data signal After amplification and symbol identification, it is decoded into a data stream.

14. Apparatus according to claim 13 wherein there is an integrator between said limiting amplifier and the symbol recognizer for reducing the bit error rate of the symbol recognizer.

15. Apparatus according to claim 14 wherein the integrator can be a digital integrator.

16. The apparatus according to claim 12, wherein the received data signal (DT) is directly connected to the data signal end of the next-stage data receiving portion when the rebroadcast is performed.

17. Apparatus according to claim 16 wherein a data processor is provided between the receiving portion and the data interface of the transmitting portion for modifying the content of the data broadcast.

18. A method of broadcasting data using an L-R channel in an FM broadcast transmission system, the method comprising the steps of:

a) setting a mode control signal (mode) of the mode control end in the transmitting portion;

b) when performing stereo broadcasting, the mode control signal (mode) of the transmitting end stops the data transmitting part, and the stereo encoder works normally to obtain the baseband signal of the FM broadcasting;

c) when performing FM L - R data broadcasting, the mode control signal (mode) of the transmitting end activates the data transmitting portion, disconnecting the first transfer switch (KS1) from the output of the DSB-SC modulator And connecting to the data transmitting portion to transmit data, and disconnecting the second switching switch (KS2) from the «output terminal of the frequency divider to cut off the pilot signal;

19. The method according to claim 18, wherein in step a), the comparator compares the similarities and differences of the left and right (L, R) two-way sound «r input signals to automatically control the mode control signal (mode). .

20. The method of claim 18, wherein said step a) is controlled by a manual control mode.

21. The method of claim 18, wherein the step c) further comprises:

d) Encode the incoming data stream.

22. The method of claim 18, further comprising, when performing a data relay, the data signal

(DT) a step of directly transmitting to the data signal terminal of the other data transmitting portion, and optionally a step of modifying the content of the digital broadcast with the set data processor between the receiving portion and the data interface of the transmitting portion .

23. The method of claim 21 wherein said encoding step d) further comprises the step of encoding the data stream using a variable width code characterized by a width of the symbol width The threshold value conveys digital information, which is a bipolar non-return-to-zero pulse signal, each of which is a symbol, and the different widths of the pulses represent different information.

24. The method of claim 23, wherein the pulse width of the variable width code can have two or more of a divisor value to form a binary or multivariate broadening code, wherein

The type of symbol with the shortest pulse width is set to S code, and the continuous S code is called even "S" code string;

The other types of variable width codes are L codes, and consecutive L codes are called "L" code strings;

Each segment is composed of information strings consisting of the same kind of cells. Before each group, a cell type character is transmitted, and then the length information of the group is transmitted. The symbol type character starts with an L code and is composed of several L symbol, if necessary, with a specific code string consisting of the appropriate S symbol, each S symbol representing a cell defined by this (before it) class 3⁄4 symbol until the next type character appears.

25. The method of claim 24 wherein the spectral characteristics of the binary variable width code are:

Smin + Lmax + 1

Fdn = χ B

2 χ [(Lmax + 1) χ Κ + Smin]

Smin + 3 χ (Lmax + 1)

Fup = x B

2 x [(Lmax + 1) χ + Smin]

Symbol rate B is satisfied

2 χ [(Lmax + 1) x K + Smin|

B = x Fdn

Smin + Lmax + 1

Or

2 x |(Lmax + 1) χ K + Smin]

B = x Fup Smin + 3 x (Lmax + 1)

By adjusting the values of Lmax, Smin K and B, the spectrum, anti-interference ability and data transmission rate of the variable width code can be determined.

26. The method according to claim 25, wherein when Lraax is infinite (LX), encoding can be performed by a direct encoding method, that is, directly making the L code correspond to the character "1" and the S code corresponding to the character "0". Or the L code corresponds to the character "0" so that the S code corresponds to the character "1", thereby eliminating the cell type character.

27. The method of claim 25, wherein the encoding steps when Lmax is not infinite include:

1) Set the variable width code to have two "L" code strings of different lengths, respectively, as the characters of the "0" and "1" characters;

2) When a character of the "0" or "1" character appears in the data stream, the encoder first extracts a length of the "L" code;

4) When the same character appears consecutively after the character, Code 2 converts each character in the string into an "S" code;

5) When different characters appear after the characters appear different characters or consecutive identical characters, the encoder rotates the "L" code of the other length;

6) Repeat steps 4) - 6) «1 to get the encoded data.

28. The method of claim 25, wherein the polarity synchronization step comprises:

1) Set a length of "L" code to indicate that the cell type has changed.

2) Performing polarity synchronization processing on the binary digital information to find and correct the polarity reversal phenomenon during the decoding process, the polarity synchronization step including:

29. The method of claim 28, wherein the polarity synchronization step comprises:

1) Set a "polar sync" and a "sync flip";

2) "add 1" processing on the binary digital information so that the polarity synchronization character does not exist in the processed data stream;

3) Perform "plus 0" processing on the binary digital information so that the synchronous reflection is not present in the processed data stream.

4) Perform "add synchronization" processing on the data stream processed by "add 1" and "add 0", divide the data stream into "blocks", and insert appropriate number of polarity synchronization between the blocks. symbol.

30. The method according to claim 28, wherein when the data block is detected by using a "data packet", the separator of the data packet can be used as a polarity synchronization character, and the character form reversed by the separator is used as Synchronize the reflection.

31. The method as recited in claim 25, wherein the encoding step of transmitting the Miller code information (M2, M3, M4) with the binary variable width code comprises:

1) setting the variable width code into a series of "L" code strings having three different lengths, respectively, as the type symbols of the three symbols (M2, M3, M4) of the Miller code; 2) When the first symbol (M2) string appears in the Miller code data stream, the encoder extracts the L code of the first length and converts each of the same symbols in the code string into an S code. ;

3) When a second symbol (M3) string appears in the Miller code data stream, the encoder grabs the second length L code and converts each of the same symbols in the concatenated string into one S symbol;

4) When a third symbol (M4) string appears in the Miller code data stream, the encoder detects the third length L code and converts each of the same symbols in the concatenated string into one S symbol;

5> Repeat the above 2) - 4) to obtain the encoded data stream.

32. The method of claim 25, wherein the encoding step of transmitting the Miller code information (M2, M3, M4) with the binary variable width code comprises:

The variable width code is set to be composed of two or less L codes, and an appropriate S code, to form three different symbol strings as the type symbols of the three Miller code symbols, thereby obtaining the Miller code. Encoded data.

33. The method of claim 31 or 32, wherein the code string in the encoding step can also be a single symbol.

34. The method of claim 21, further comprising:

e) a step of waveform synthesis of the encoded data signal, wherein the waveform synthesizer determines a waveform of the pulse element based on a code form of the checked data stream.

35. The method of claim 34, wherein the shape of the pulse element is a set of pre-optimized waveform modules.

36. The method according to claim 25, wherein when the Lmax = l, Smin = 1, (i.e., L1S1) pattern encoding is used, the effective frequency band of the variable width code signal is 22.714 - 53KH.

37. The method according to claim 25, wherein when Lmax = l, Smin = 25, (i.e., L1S25) code type coding, the effective band of the variable width code signal is 53.069 - 60.931KH.

38. The method according to claim 25, wherein when Lmax = l, Smin = 16, (i.e., L1S16) code type coding, the effective frequency band of the variable width code signal is 61.2 - 74.8KH.

39. The method according to claim 25, wherein when the Lmax = l, Smin = 8, (ie, L1S8) pattern coding, the effective frequency band of the variable width code signal is 53 - 75KH.

40. The method according to claim 26, wherein when the Lmax = ∞l, Smin = 1, (ie, LXS1) pattern coding is used, the effective frequency band of the variable width code signal is 20 - 60KH.

41. The method according to claim 24, wherein when there are three L codes, and the pulse width ratio of the S code to the L code is 1:2.0:2.5:3.0, the quaternion Lmax = l, Smin = 1 is used (ie The L1S1) pattern encodes the binary information converted into the Miller code, and the effective spectrum of the variable width code signal is 22.925 -

75KHz.

42. A method of receiving data for an L-R channel in an FM broadcast system, the method comprising the steps of:

a) setting a bandpass filter at the receiving end to receive the transmitted broadcast baseband signal (including the data signal), b) setting a pilot identifier at the receiving end for identifying the pilot signal from the base signal,

C) arranging a third transfer switch (KR) between the band pass filter and the data receiving portion, the third transfer switch (KR) being connected to the pilot of the pilot recognizer,

d) when the pilot identifies a pilot signal from the broadcast baseband signal, the mode control signal (mode) of the detection terminal disconnects the third switch (KR) from the dynasty filter, stopping The reception of the data signal and the stereo decoder work normally, thereby obtaining a stereo broadcast signal,

e) when the pilot recognizer does not recognize the pilot signal from the 3⁄4 incoming signal, its mode control signal at the wheel end causes the third switch (KR) to be connected to the band pass filter, thereby realizing the data signal receive.

43. The method of claim 42 wherein said receiving step e) further comprises:

f) after the amplitude-enhanced data signal synthesized by the received waveform is subjected to clipping amplification, pulse width discrimination is performed to restore the pulse width code;

g) Decoding the data signal encoded by the pulse width code.

44. The method of claim 43 wherein said step f) further comprises:

Π) sending the variable width coded data signal after being clipped into an integrator to eliminate the distortion of the L code and the S code, thereby reducing the bit error rate of the symbol recognizer;

F2) The integrated data signal is sent to the symbol recognizer to restore the widened code.

45. The method according to claim 42, further comprising the step of transmitting the received data signal (DT) directly to the data signal terminal (DT) of the next-stage data receiving portion when performing data rebroadcasting, and Optionally, the step of modifying the content of the data signal with the set data processor between the receiving device and the data interface of the transmitting device.

46. The method of claim 43 wherein said decoding step (g) comprises:

h> identifying the cell type character in the data stream encoded by the variable width code to determine the type of cell to be sent;

i) Convert each subsequent S code into a determined cell until the next type character appears.

47. The method according to claim 43, wherein when the binary variable width code is used to transmit data, when Lmax is infinite (LX), the decoding step g) comprises directly converting the L code and the S code into corresponding Step 3⁄4 of the "0" or "1" character.

48. The method of claim 43 wherein said decoding step further comprises: when the data is transmitted in the form of a "packet", said decoded data is subjected to "minus 1" and "minus 0". deal with.

49. A system for performing FM L_R data broadcasting, the broadcasting system comprising a transmitting portion and a receiving portion, the transmitting portion comprising: a check-in having two left and right channels (L, R) a stereo encoder, and an output, the receiving portion comprising a receiving end, a stereo decoder and a detecting end; the system is characterized by:

The sending part also includes: a data transmitting portion, the «r out is connected to the adder in the stereo encoder for providing a data signal to be transmitted «r;

a first transfer switch (KS1) disposed between the DSB-SC modulator, the data transmitting portion and the first band pass filter for selectively receiving a data signal or an audio signal;

a second transfer switch (KS2) disposed between the frequency dividing and narrow band filters for selectively turning on or off the pilot signal;

a mode control end connected to the first and second switches (KS1, KS2) for controlling a state of the switch (KS1, KS2), the mode control end also being connected to the data transmission, for Controlling the data transmitting portion to transmit the data signal;

The receiving part also includes:

a data receiving portion for receiving the transmitted data signal (DT);

a second band pass filter having a check-in end connected to the receiving end for separating a data signal (DT) from the broadcast baseband signal;

a pilot recognizer whose input ^ is also connected to the receiving end for identifying the pilot signal and at its detection terminal «discharge mode control signal (mode);

a third transfer switch (KR) disposed between the second band pass filter and the data receiving portion and connected to the «detector terminal of the pilot recognizer;

The mode control signal detected by the pilot identifier is returned to the data decoder by the third transfer switch (KR> to selectively transfer the data signal (DT) to the data stream.

50. The subsystem according to claim 49, wherein said transmitting portion and said receiving portion further comprise a data signal end for directly receiving a data signal transmitted by a data signal end of a previous stage or directly directly transmitting data at the time of retransmission The signal is transmitted to the data signal terminal of the next stage.

51. The system of claim 49, wherein a data processor is further disposed between the receiving portion and the data interface of the transmitting portion for modifying data stream content.

52. The system of claim 49, wherein the mode control end of the receiving portion is connectable to the mode control terminal of the transmitting portion during the rebroadcast to relay the mode control signal.

53. A method of frequency modulated L_R data broadcasting, the method comprising the following steps:

c) when performing FM L-R data broadcasting, the mode control signal (mode) of the transmitting end activates the data transmitting portion, and the first switching switch (KS1) and the DSB-SC modulator detection terminal ( DSB - SC) is disconnected, and is connected to the data transmitting portion to transmit data, and the second transfer switch (KS2) is connected to the output of the frequency divider to cut off the pilot signal;

d) setting a second band pass filter at the receiving end to receive the transmitted broadcast baseband signal (including the data signal); e) setting a pilot identifier at the receiving end for identifying the pilot signal from the baseband signal; f) providing a third transfer switch (KR) between the band pass filter and the data receiving portion, said third a transfer switch (KR) connected to the detection of the pilot identifier;

g) when the pilot recognizer identifies the pilot signal from the broadcast baseband signal, the mode control signal (mode) of the output causes the third transfer switch (KR) and the band pass filter Disconnect, stop receiving the data signal, and make the stereo decoder work normally, thereby obtaining a stereo broadcast signal;

h) when the pilot identifier does not recognize the pilot signal from the detected signal, the mode control signal at the detecting end causes the third switching switch (KR) and the band pass filter Turn on, thereby achieving the reception of the data signal.

54. The subsystem of claim 53, wherein the transmitting portion and the receiving portion further comprise a data signal end for directly receiving the data signal transmitted by the data signal end of the previous stage or directly transmitting the data during the rebroadcasting The signal is transmitted to the data signal terminal of the next stage.

55. The system of claim 53, wherein a data processor is further disposed between the receiving portion and the data interface of the transmitting portion for modifying data stream content.

56. The system of claim 53, wherein the mode control end of the receiving portion is connectable to the mode control terminal of the transmitting portion during the rebroadcast to relay the mode control signal.

57. A system for transmitting data using an FM broadcast, the system comprising a transmitting portion and a receiving portion, the transmitting portion comprising: a check-in end of two left and right channels (L, R), a stereo encoding And an output; the system is characterized by:

The sending part also includes:

a data transmitting portion connected to the adder of the stereo encoder,

a first transfer switch (KS1) disposed between the band pass filter and the adder for selectively receiving a low rate data signal or a high rate data signal;

a second transfer switch (KS2) disposed between the narrow band filter and the adder for selectively turning the pilot signal on or off;

a mode control end connected to the first and second switches (KS1, KS2) for controlling a mode in which the data transmitting portion transmits the data signal;

The receiving part also includes:

a data receiving portion for receiving the transmitted data signal (DT);

a low speed band pass filter having a check-in terminal coupled to the receiving end for separating a low speed data signal from the broadcast baseband signal;

a high speed band pass filter having a check-in terminal coupled to the receiving end for separating a high speed data signal from a broadcast baseband signal;

a pilot recognizer whose check-in end is also connected to the receiving end for identifying the pilot signal and outputting a mode control signal (mode) at its rounding end; A third transfer switch (KR) is disposed between the high speed filter and the digital receiving portion and connected to the ίίτ output of the pilot recognizer.

58. The subsystem according to claim 57, wherein said transmitting portion and said receiving portion further comprise a data signal end for directly receiving a data signal transmitted by a data signal end of a previous stage or directly directly transmitting data during rebroadcasting. The signal is transmitted to the data signal terminal of the next stage.

59. The system of claim 57, wherein a data processor is further disposed between the receiving portion and the data interface of the transmitting portion for modifying data stream content.

60. The system of claim 57, wherein the mode control terminal of the receiving portion is connectable to the mode control terminal of the transmitting portion during the rebroadcast to relay the mode control signal.

61. A method of transmitting a data signal using an FM broadcast, the method comprising the following steps

b) when performing stereo wide, the mode control signal (mode) of the transmitting end closes the first transfer switch (KS1), and sends the DSB-SC signal to the adder, so that the data transmitting part is in a low rate transmitting state ( For example, mode four);

c) when broadcasting the mono program, the mode control signal (mode) of the transmitting end cuts off the DSB-SC signal through the first transfer switch (KS1), and cuts off the pilot signal through the second transfer switch (KS2), thereby The data transmission part is in a high rate data transmission state (eg, mode six);

d) setting a high-speed bandpass filter at the receiving end for receiving the low-rate data signal transmitted during stereo broadcasting;

e) setting a low-speed bandpass filter at the receiving end for receiving the high-rate data signal transmitted during the mono broadcast;

f) setting a pilot recognizer at the receiving end for identifying the pilot signal from the broadcast baseband signal; g) setting a third transfer switch (KR) between the high and low speed band pass filters and the data receiving portion, The third transfer switch (KR) is connected to the pilot identifier;

h) when the pilot recognizer recognizes the pilot signal from the broadcast baseband signal, the mode control signal (mode) of the output terminal connects the low speed filter to the data receiving portion through the third transfer switch (KR) At the same time, the data receiving portion is in a low rate data receiving state;

i) when the pilot recognizer does not recognize the pilot signal from the broadcast baseband signal, the mode control signal (mode) of the output terminal enables the high speed filter and data reception through the third transfer switch (KR) Partially connected while the data receiving portion is in a high rate data receiving state.

62. The subsystem according to claim 61, wherein said transmitting portion and said receiving portion further comprise a data signal end for directly receiving a data signal transmitted by a data signal end of a previous stage or directly directly transmitting data during rebroadcasting. The signal is transmitted to the data signal terminal of the next stage.

63. The system of claim 61, wherein a data processor is further disposed between the receiving portion and the data interface of the transmitting portion for modifying data stream content.

64. The system of claim 61, wherein the mode control end of the receiving portion is connectable to the mode control terminal of the transmitting portion during the rebroadcast to relay the mode control signal.