CN107395545B - Method for realizing ROBO interweaving technology - Google Patents
Method for realizing ROBO interweaving technology Download PDFInfo
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- CN107395545B CN107395545B CN201710676926.6A CN201710676926A CN107395545B CN 107395545 B CN107395545 B CN 107395545B CN 201710676926 A CN201710676926 A CN 201710676926A CN 107395545 B CN107395545 B CN 107395545B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2626—Arrangements specific to the transmitter only
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0056—Systems characterized by the type of code used
- H04L1/0071—Use of interleaving
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
Abstract
the invention discloses a method for realizing an ROBO technology, which comprises the steps of firstly selecting an interleaving mode according to actual requirements, determining the number of actually available carriers for ROBO interleaving according to parameters, and calculating the number of OFDM symbols. One OFDM symbol is divided into several segments, and the bit number BitsInsegment contained in each Segment is related to the modulation mode. And copying a part of data to fill Npad so that the data can be transmitted by just using an integer number of OFDM symbols, calculating the bit number required to be supplemented, obtaining a complete OFDM symbol and effectively utilizing the number of subcarriers. And calculating cyclic shift parameters (Cyclicshift), and calculating data output by interleaving mapping according to Ncopies and the corresponding cyclic shift parameters (Cyclicshift) during ROBO mapping. Finally, the parameter corresponding to the corresponding mode is expressed by bit number and added into the control frame of the frame control symbol. The invention defines the cyclic shift parameter Cyclicshift and the inverted variable NumberBitsShift, the value of which is related to the copy frequency and the data modulation mode, avoids the condition that the same data information is sent on the same subchannel, and enhances the channel fading resistance of the load data.
Description
Technical Field
the invention belongs to the technical field of communication, and relates to a method for realizing an ROBO interleaving technology and application thereof in broadband power line carrier communication.
Background
The low-voltage power line carrier communication is a special communication mode for carrying out voice or data transmission on analog or digital signals in a carrier mode by using a low-voltage distribution line 380/220V subscriber line as an information transmission medium. The power grid is one of the national infrastructure networks as a private network for the delivery of electrical energy. The construction quality, mechanical strength, safety, economy, technical indexes and the like of the network are reasonably optimized through repeated demonstration. The coverage area and the capacity of the network are wide and can not be compared with any network. The power grid is therefore a good quality, scarce resource. The power line carrier technology has been developed and applied domestically for many years, and the technical standards and management procedures are quite complete and mature. With the continuous development of the power line carrier technology, the low-voltage power line carrier technology is also developed rapidly. In recent years, many enterprises which are engaged in the research and development of power line carrier technology emerge in China, such as companies like Dongfu, Fuxing, Shenzhen Ruishank, Shanghai Mizu, etc. The carrier chip is widely applied to automatic meter reading systems, alarm and safety monitoring systems, home automation systems and the like.
the basic characteristics of the power line carrier communication channel are: firstly, the method comprises the following steps: the time-varying attenuation is large. For general residential users, 220V alternating current two-wire power supply is adopted in China. Due to various random events such as continuous access and cut-out of loads on a power grid, switching on and off of electrical appliances and the like, the channel characteristics have strong time-varying property. In addition, the impedance of the power line itself also produces time-varying attenuation. Secondly, the method comprises the following steps: the signal changes are complex. Practical measurements have shown that many loads of different nature connected in parallel at different locations on the power line have a significant impact on the transmission of signals. The signal attenuation may also exhibit different characteristics at different times as the load is connected or disconnected on the power line, i.e. the load changes randomly, so the signal attenuation also changes randomly. Thirdly, the method comprises the following steps: the interference noise is diverse. The largest interference of power line carrier communication is noise, the main sources of which are all loads on the power grid, radio broadcasts, sky power, and the like.
In summary, for the above characteristics of the power line carrier communication channel, the modulated signal should have the characteristics of high spectrum utilization rate, strong noise immunity and interference resistance, suitability for transmission in a fading channel, and the like. The high anti-interference and anti-multipath fading performance is required to work well in a severe channel environment, and the output signal-to-noise ratio S/N after modulation and demodulation is larger or the error rate is lower. With the advent of fast algorithm FFT for DFT and the development of digital signal processing technology, OFDM has become a hot spot of research again. The OFDM technique has many advantages: 1) intersymbol interference can be effectively overcome, and the anti-interference capability is strong; 2) the frequency band utilization rate is high; 3) system equalization is simple, etc. The severe condition of the power line channel just gives space for the OFDM technology, and the power line channel can effectively resist various interferences in the power line network environment and realize high-speed and reliable transmission of data.
The broadband carrier communication network is a communication network which takes a low-voltage power line as a communication medium and realizes the aggregation, transmission and interaction of the power consumption information of low-voltage power users, and mainly adopts an orthogonal frequency division multiplexing technology, and the frequency band uses 2 MHz-12 MHz. The channel coding technology can greatly enhance the reliability of signal transmission, but in order to ensure the robust characteristic of data transmission in a broadband power line channel, the currently researched hot technology is not a ROBO interleaving technology, and aims to realize better reliability and robustness of power line communication. However, the current ROBO interleaving technique only utilizes diversity, and the diversity includes the same data each time, and cannot fully utilize the advantage of the diversity.
disclosure of Invention
The invention aims to provide a method for realizing an ROBO interleaving technology aiming at instability in a broadband carrier communication process, and the obtained ROBO interleaving technology is applied to broadband carrier communication.
In order to solve the above problems, the technical scheme adopted by the invention is an implementation method of an ROBO interleaving technology, which comprises the following steps:
Step 1: selecting an interleaving mode according to actual requirements;
Step 2: calculating the number of OFDM symbols: according to the bit number contained in one symbol of the actual available carrier number, BitsPersymbol (BPC) Ncarrier _ ROBO), calculating the required OFDM symbol number Nofdm (Nraw/BitsPersymbol), wherein Nraw is the data bit number output by the previous channel interleaving, namely the data bit number entering the ROBO interleaving; BPC is the number of bits carried per subcarrier; ncarrier _ ROBO is the number of subcarriers used for ROBO interleaving.
And step 3: dividing an OFDM symbol into several segments, wherein the bit number of each Segment is BitsInsegment related to the modulation mode, the BitsInsegment is BPC carrier Insegment, the carrier Insegment is the number of sub-carriers contained in each Segment, and if the last OFDM symbol is incomplete, the ROBO interweaves to make full use of the carriers through supplementary data;
And 4, step 4: in order to avoid the situation that the useful subcarriers of the last OFDM symbol only use one part, copying and filling a part of data, wherein the number of copying and filling bits is Npad, so that the data can be transmitted by just using an integral number of OFDM symbols, calculating the number of bits contained in the last symbol, if the number of bits of the last symbol is not 0, calculating the number of bits contained in the last Segment of incomplete Segment if an incomplete symbol exists, calculating the number of bits to be supplemented according to the number of bits, obtaining the complete OFDM symbol, and effectively utilizing the number of subcarriers;
And 5: a cyclic shift parameter, cyclic shift, is calculated which determines the length of the bit sequence that needs to be duplicated for each copy of the data, which is related to the number of copies, ncopes. After shifting, the situation that the same data information is sent on the same sub-channel is avoided, the channel fading resistance of the load data is enhanced, namely the data content copied each time is different, and the anti-interference performance is also improved by utilizing diversity;
Step 6: ROBO mapping is carried out, data output by interleaving mapping is calculated according to the copying times Ncopies and the corresponding shifting parameter Cyclicshift, the data filled in each copying is different, diversity is utilized, and the reliability of the data is improved;
and 7: the parameters corresponding to the corresponding mode are expressed by bit number and added into the control frame of the frame control symbol, the receiving end combines and processes the received data according to the maximum ratio to obtain diversity gain and enhance the equivalent signal-to-noise ratio of the data, and then the original data can be obtained by de-interleaving the corresponding parameters, thereby enhancing the stability in data transmission.
Preferably, the interleaving mode in step 1 may be PB136 or PB 520.
When the interleaving mode is selected in step 1, an extension mode is also supported to be suitable for some special occasions, and the number of actually available carriers for ROBO interleaving Ncarrier _ ROBO is determined according to parameters.
The number of subcarriers actually used for transmission in step 2 differs depending on the ROBO interleaving mode, and the number of generated OFDM symbols also differs.
In step 4, Npad is a part of the original input data.
The value of the cyclic shift parameter cyclic shift defined in step 5 and step 6 is related to the number of copies Ncopies and the number of bits contained in each subcarrier BPC, so that the situation that the same data information is sent on the same subchannel is avoided, the channel fading resistance of the payload data is enhanced, namely the data content of each copy is different, the mapped OFDM symbols are different, and the system stability is improved by utilizing the diversity characteristic.
The invention has the following beneficial effects:
1. The invention utilizes a multi-copy data model established based on the diversity copy criterion to research the ROBO interleaving mode which is suitable for different actual communication conditions and communication distances.
2. The invention defines the cyclic shift parameter Cyclicshift and the inverted variable NumberBitsShift, the value of which is related to the copy frequency and the data modulation mode, avoids the condition that the same data information is sent on the same subchannel, and enhances the channel fading resistance of the load data.
3. The invention obtains the data after ROBO interweaving, and obtains diversity gain by using a maximum ratio combining method, thereby enhancing the equivalent signal-to-noise ratio of the data to receive the data.
4. the invention provides an ROBO interleaving technology integrating diversity replication and interleaving, which performs replication on an effective signal for a certain number of times, wherein the ROBO characteristic is stronger when the replication number is more. By carrying out ROBO transmission on signals, the broadband power line communication has good robust characteristics.
Drawings
FIG. 1 is a symbol diagram after ROBO interleaving;
FIG. 2 is a schematic diagram of OFDM symbols corresponding to two different interleaving parameters; wherein 2a is a first copy format of HR _ ROBO _0 mode (ROBO basic mode), 2b is a first copy format of ROBO extension mode, and 2c is a second copy format of ROBO extension mode;
fig. 3 is a flow chart of ROBO interleaving mapping.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings. The ROBO interleaving technology provided by the invention carries out diversity duplication and one-time ROBO interleaving on payload data besides channel coding and channel interleaving. The original data is subjected to diversity copying and supplementation through the technology so as to ensure good communication performance when the channel is poor. The method for duplicating data in diversity and the number of usable subcarriers are related to the required diversity times and modulation mode, and the data contained in each duplication may be different, so as to ensure different modulation modes and different interleaving modes for different communication requirements. In addition, ROBO interleaving explicitly requires that the number of subcarriers used for signal transmission must be an integer multiple of the number of copies to ensure a feasible number of carrier modulations. By carrying out ROBO transmission on signals, the broadband power line communication has good robust characteristics.
as shown in fig. 1, several schematic diagrams of ROBO interleaving are shown, and the ROBO interleaving technique according to the present invention is required to satisfy various communication requirements, so that the ROBO interleaving parameters are first calculated when determining the structure. The copy times are determined by the known data length and the channel condition, the higher the copy times, the more the ROBO interleaving times and the stronger the stability, and the more accurate received data can be ensured when the communication condition is poor.
As shown in fig. 2, two different interleaving parameters are corresponding to OFDM symbols. Different shift parameters, namely, cyclic shift and inverse variable NumberBitsShift are obtained respectively corresponding to the conditions that the data size is PB520(520 bytes), the modulation mode is QPSK, the copy number is 2, the data size is PB520, 16QAM is used for modulation, and the data size is 2 copies, so that OFDM symbols containing different subcarrier numbers are formed.
First HR _ ROBO _0 mode specific parameter (assuming number of available carriers 411):
The number of copies is 2, each OFDM symbol is divided into two segments of actually used subcarriers, the number of subcarriers used in each segment is [411/2] ═ 205, QPSK modulation is performed, each subcarrier contains 2 bits, the number of bits per segment is 205 × 2 ═ 410, the number of bits per symbol is 410 × 2 ═ 820, the total number of bits input is 520 × 8 ═ 4160, the number of complete OFDM symbols required is [4160/410 × 2] ═ 5, i.e., the last symbol does not use all subcarriers, in order to improve the carrier utilization and utilize diversity characteristics, a means of supplementary data is adopted to fill the complete OFDM symbol, the number of bits of the last symbol is 4160-, then Npad-the number of bits per segment-the number of bits in the last segment 410-60-350, its shift parameter Cyclicshift is (0,0), the inverse variable nummberbitshift is 0, and the resulting OFDM symbol, i.e. the input data plus the supplemental data, is copied each time, see fig. 2a in particular.
the second specific parameter:
The number of copies is 2, each OFDM symbol is divided into two segments of actually used subcarriers, the number of subcarriers used in each segment is [411/2] × 205, each subcarrier carries 4 bits by adopting 16QAM modulation, the number of bits in each segment is 205 × 4 ═ 820, the number of bits in each symbol is 410 × 4 ═ 1640, the total number of bits input is 520 × 8 ═ 4160, the number of required complete OFDM symbols is [4160/1640] ═ 2, that is, the last symbol does not use all subcarriers, in order to improve the carrier utilization rate and utilize diversity characteristics, a means of supplementary data is adopted to fill the complete OFDM symbol, the number of bits in the last symbol is 4160-, it can be seen that the last segment is incomplete, and the supplemental data completes the last segment, then Npad is the bit number per segment — the bit number of the last segment is 880-60, 820, the shift parameter circhift is (0,1), the inversion variable nummberbitshift is 60, and the OFDM symbol obtained by each copying, i.e., the input data, is added with the supplemental data, which is specifically shown in fig. 2b and 2 c.
As shown in fig. 3, the implementation process of the method of the present invention specifically includes the following steps:
step 1: selecting an interleaving mode (such as PB136 or PB520) according to actual requirements, wherein the specific mode is shown in Table 1, the method also supports an expansion mode, is suitable for some special occasions, and determines the number of carriers actually available for ROBO interleaving according to parameters (such as copy number)
ROBO basic mode
ROBO expansion mode
TABLE 1
Step 2: calculating the number of OFDM symbols: calculating the required OFDM symbol number Nofdm Nraw/BitsPersymbol (Nraw is the data output by the previous channel interleaving, namely the data entering the ROBO interleaving) according to the bit number BitsPersymbol (BPC) Ncarrier _ ROBO (BPC is the bit number modulated by each subcarrier) contained in one symbol of the actual available carrier number
and step 3: one OFDM symbol is divided into several segments, the bit number (BitsInsegment) of each Segment is related to the modulation mode, the BitsInsegment (BPC) carrier length (the number of sub-carriers contained in each Segment) may be incomplete, and the last OFDM symbol may be incomplete, and ROBO interleaving makes the carriers fully utilized by the supplementary data.
And 4, step 4: in order to avoid the situation that only one part of the useful sub-carriers of the last OFDM symbol is used, a part of data is copied and filled with Npad (part of the original input data), so that the data can be just used for an integer number of OFDM symbols
And (5) transmitting. Calculating the bit number BitsInLastSymbol contained in the last symbol to see whether to supplement Npad
If the bit number of the last symbol is not 0, there is an incomplete symbol, and the bit number contained in the last Segment of incomplete Segment is calculated
The bit number Npad required to be supplemented is calculated as BitsInSegment-BitInLastSegment, and thus a complete OFDM symbol is obtained, and the number of subcarriers is effectively used.
and 5: a cyclic shift parameter, cyclic shift, is calculated which determines the length of the bit sequence that needs to be duplicated for each copy of the data, and is related to Ncopies. After the shift, the condition that the same data information is sent on the same sub-channel is avoided, and the channel fading resistance of the load data is enhanced. I.e. the data content of each copy is not the same, exploiting diversity also improves the interference immunity. The specific parameters are calculated as follows:
1) If the number of times of copying ncopes is 1, the shift parameter Cyclicshift (0) of the first copy is 0;
2) If ncopes is 2, the shift parameter of the first copy is that cyclic shift (0) is 0, and the second copy is divided into two cases:
a. If the bit number of the last symbol, BitsInLastSymbol, is not enough for a length of BitsInSegment, the shift parameter cycle (1) is 0
b. The bit number of the last symbol, BitsInLastSymbol, is greater than the length of one segment, and the shift parameter, cycle (1), is 1
3) If Ncopies is 4, the situation is complicated, and the specific details are as follows:
a. If the bit number of the last symbol, BitsInLastSymbol, is less than BitsInSegment, i.e. the last symbol has only one Segment, the shift parameter Cyclhift (0,1,2,3) of 4 copies is (0,0, 0)
b. if the last symbol contains 2 segments, i.e. BitsInLastSymbol [ < 2 × BitsInSegment, then the shift parameter circshift (0,1,2,3) ═ 0,0,1,1)
c. if the last symbol contains 3 segments, i.e. BitsInLastSymbol [ < 3 × BitsInSegment, then the shift parameter circshift (0,1,2,3) ═ 0,0,0,0)
d. If the last symbol contains 4 segments, i.e., BitsInLastSymbol [ < 4 × BitsInSegment ], then the shift parameter circshift (0,1,2,3) ═ 0,1,2,3)
4) if Ncopies is 5, there are two cases, specifically, the following
a. If the last symbol is less than 5 segments, i.e. BitsInLastSymbol < ═ 4 × BitsInSegment, then the shift parameter cyclichhift (0,1,2,3,4) ═ 0,0,0,0,0) for 5 copies
b. If the last symbol contains 5 segments, i.e., BitsInLastSymbol [ < 5 × BitsInSegment ], then the shift parameter of 5 copies, circhift (0,1,2,3,4) ═ 0,1,2,3,4)
5) If Ncopies is 7, there are two cases, specifically, the following
a. If the last symbol is less than 7 segments, i.e., BitsInLastSymbol < ═ 6 BitsInSegment, then the shift parameter cycle of 7 copies is (0,1,2,3,4,5,6) > (0,0,0,0,0,0,0, 0)
b. if the last symbol contains 7 segments, i.e., BitsInLastSymbol < ═ 7 × BitsInSegment, then the shift parameter cycle shift of 7 copies is (0,1,2,3,4,5,6) ═ 0,1,2,3,4,5,6)
6) if Ncopies is 11, there are two cases, specifically, the following
a. If the last symbol is less than 11 segments, i.e., BitsInLastSymbol < ═ 10 × BitsInSegment, then the shift parameter cycle of 11 copies is (0,0,0,0,0,0,0,0,0, 10) ═ 0,1,2,3,4,5,6,7,8,9,10)
b. If the last symbol contains 11 segments, i.e., BitsInLastSymbol [ -11 × BitsInSegment, then the shift parameter cycle of 11 copies is (0,1,2,3,4,5,6,7,8,9,10) ═ 0,1,2,3,4,5,6,7,8,9,10)
Step 6: and ROBO mapping, namely calculating data output by interleaving mapping according to Ncopies and corresponding shift parameter Cyclicshift, wherein the data filled in each copying is different, so that diversity is utilized, and the reliability of the data is improved.
If k is 1 to ncopes, and if the shift parameter cycle shift (k) is 0, the ROBO interleaved output data copied each time is the input data plus the supplementary data Npad, and the symbols are as shown in fig. 1;
If the corresponding shift parameter circhift (k) is 1, defining an inverted variable nummberbtsshift (the last nummberbtsshift data of the input data is taken), and then following the supplementary data Npad, the remaining Segment is composed of the input data in sequence, and the symbol is as shown in fig. 1;
and 7: the parameters corresponding to the corresponding mode are expressed by bit number and added into the control frame of the frame control symbol, the receiving end combines and processes the received data according to the maximum ratio to obtain diversity gain and enhance the equivalent signal-to-noise ratio of the data, and then the original data can be obtained by de-interleaving the corresponding parameters, thereby enhancing the stability in data transmission.
In addition, the mode selection in the first step of the invention needs to be selected by the mode in the first table, thereby achieving better effect
In the step 2, when the mode is selected, due to the fact that the number of copies, the data length and the modulation mode are different, the number of subcarriers used for actual transmission, the number of generated OFDM symbols and the data contained in each symbol are different, so that the shift parameters and the inversion variables in the step 3 are different, the symbol interleaved each time is calculated according to a specific calculation formula, the situation that the same data information is sent on the same subchannel is avoided, and the channel fading resistance of the load data is enhanced.
specifically, the number of subcarriers bitspsymbol ═ BPC ═ Ncarrier _ robo is actually used
In order to avoid the situation that only one part of the useful sub-carriers of the last OFDM symbol is used, a part of data is copied to fill Npad, so that the data can be transmitted by using an integral number of OFDM symbols. Calculating the bit number of the last Segment
the bit number Npad required to be supplemented is calculated as BitsInSegment-BitInLastSegment, and thus a complete OFDM symbol is obtained, and the number of subcarriers is effectively used.
After the completion of the filling, ROBO mapping needs to be performed on the data, a specific mapping mode is related to a shift parameter Ncopies and an inversion variable nummberbitshift, and related detailed parameters are shown in table 2.
TABLE 2
The ROBO interleaving technology obtained by the invention fully utilizes the subcarriers, obtains different interleaving data by defining a cyclic shift parameter, avoids the condition that the same data information is sent on the same subchannel, realizes a data symbol with good robust characteristic, and enhances the channel fading resistance of the load data. The ROBO interleaving technology designed by the invention is different according to the fading condition of the power line channel and the distance between the transceivers, and is suitable for various communication requirements. The receiving end adopts a maximum ratio combining method to obtain diversity gain and enhance the equivalent signal-to-noise ratio of data, and the method can be applied to broadband power line carrier communication to ensure that the broadband carrier communication has good reliability.
the invention utilizes a multi-copy data model established based on the diversity copy criterion to research the ROBO interleaving mode which is suitable for different actual communication conditions and communication distances. According to the method, the value of the cyclic shift parameter Cyclicshift and the inversion variable NumberBitsShift is related to the copy frequency and the data modulation mode, the condition that the same data information is transmitted on the same sub-channel is avoided, and the channel fading resistance of the load data is enhanced. And obtaining ROBO interleaved data, and obtaining diversity gain by using a maximum ratio combining method to enhance the equivalent signal-to-noise ratio of the data. The method carries out in-phase weighting combination on multi-path signals, the weight of each branch is determined by the ratio of the signal power corresponding to each branch signal to the noise power, and the SNR of the combined output is equal to the sum of the SNR of each branch, so that even if each branch signal is very poor so that no branch signal can be independently and correctly demodulated, a correctly demodulated signal meeting the SNR requirement can still be synthesized and output after the maximum ratio combination. Simulation results can show that after a received signal is processed in a common interleaving mode, due to the fact that power line channels are seriously faded, data information of each sub-channel is seriously affected, and the data information of each sub-channel cannot be correctly demodulated; the ROBO interleaving mode obtained by the invention is used for processing the received signals, because the original data are copied m times when ROBO interleaving is carried out on the data, the data information of each subchannel is fully utilized when the maximum ratio is combined, the output SNR is equal to m times of the SNR of each subchannel, the SNR level reaches the requirement that the load data can be correctly demodulated, and the bit error performance of the system is obviously improved. And further, the OFDM symbol with strong reliability and high stability is obtained, and the method is well applied to broadband carrier communication.
Claims (6)
1. A method for realizing a ROBO interleaving technology is characterized by comprising the following steps:
Step 1: selecting an interleaving mode according to actual requirements;
Step 2: calculating the number of OFDM symbols: according to the number of bits contained in one symbol of the actual number of available carriers, BitsPersymbol is BPC Ncarrier _ ROBO, BPC is the number of bits carried by each subcarrier, Ncarrier _ ROBO is the number of subcarriers used by ROBO mode interleaving, the required number of OFDM symbols Nofdm is Nraw/BitsPersymbol, Nraw is data output by previous channel interleaving, namely data entering ROBO interleaving;
And step 3: dividing an OFDM symbol into several segments, wherein the bit number of each Segment is BitsInsegment related to the modulation mode, the BitsInsegment is BPC carrier length, the carrier length is the number of sub-carriers contained in each Segment, and if the last OFDM symbol is incomplete, the ROBO interweaves to make full use of the carriers through supplementary data;
And 4, step 4: in order to avoid the situation that the useful subcarriers of the last OFDM symbol only use one part, copying a part of data to fill Npad, wherein Npad is the number of copy filling bits, so that the data can be transmitted by just using an integer number of OFDM symbols, calculating the number of bits contained in the last symbol, if the number of bits of the last symbol is not 0, calculating the number of bits contained in the last Segment of incomplete Segment if an incomplete symbol exists, calculating the number of bits to be supplemented, obtaining the complete OFDM symbol, and effectively utilizing the number of subcarriers;
and 5: calculating a cyclic shift parameter (cyclic shift), which determines the length of a bit sequence needing to be copied and shifted when data is copied each time and is related to Ncopies, wherein Ncopies is the number of times of copying, and after shifting, the situation that the same data information is sent on the same subchannel is avoided, the channel fading resistance of the load data is enhanced, namely the data content copied each time is different, and the interference resistance is also improved by utilizing diversity;
Step 6: ROBO mapping is carried out, data output by interleaving mapping is calculated according to Ncopies and corresponding shift parameter Cyclicshift, the data filled in each copying is different, diversity is utilized, and data reliability is improved;
And 7: the parameters corresponding to the corresponding mode are expressed by bit number and added into the control frame of the frame control symbol, the receiving end combines and processes the received data according to the maximum ratio to obtain diversity gain and enhance the equivalent signal-to-noise ratio of the data, and then the original data can be obtained by de-interleaving the corresponding parameters, thereby enhancing the stability in data transmission.
2. The method of claim 1, wherein the interleaving mode in step 1 can be PB136 or PB 520.
3. The method of claim 1, wherein an extension mode is further supported when the interleaving mode is selected in step 1 to be suitable for some special occasions, and the number of carriers Ncarrier _ ROBO actually available for ROBO interleaving is determined according to parameters.
4. The method of claim 1, wherein the number of subcarriers used for actual transmission in step 2 varies according to the ROBO interleaving mode, and the number of generated OFDM symbols also varies.
5. the method of claim 4, wherein the Npad in step 4 is a part of original input data.
6. The method of claim 1, wherein a value of cyclic shift parameter cyclic shift defined in step 5 and step 6 is related to ncopes and BPC, so as to avoid a situation that the same data information is transmitted on the same sub-channel, thereby enhancing a channel fading resistance of payload data, i.e. the data content of each copy is different, the mapped OFDM symbols are different, and the system stability is improved by using a diversity characteristic.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1463255A1 (en) * | 2003-03-25 | 2004-09-29 | Sony United Kingdom Limited | Interleaver for mapping symbols on the carriers of an OFDM system |
| CN102113231A (en) * | 2008-06-06 | 2011-06-29 | 马克西姆综合产品公司 | Blind channel quality estimator |
| CN104917587A (en) * | 2014-03-13 | 2015-09-16 | 钜泉光电科技(上海)股份有限公司 | Data block interleaving and de-interleaving method in communication equipment and device thereof |
| CN105991499A (en) * | 2015-02-06 | 2016-10-05 | 钜泉光电科技(上海)股份有限公司 | OFDM power-frequency synchronous power carrier communication and physical layer coded modulation method |
-
2017
- 2017-08-09 CN CN201710676926.6A patent/CN107395545B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1463255A1 (en) * | 2003-03-25 | 2004-09-29 | Sony United Kingdom Limited | Interleaver for mapping symbols on the carriers of an OFDM system |
| CN102113231A (en) * | 2008-06-06 | 2011-06-29 | 马克西姆综合产品公司 | Blind channel quality estimator |
| CN104917587A (en) * | 2014-03-13 | 2015-09-16 | 钜泉光电科技(上海)股份有限公司 | Data block interleaving and de-interleaving method in communication equipment and device thereof |
| CN105991499A (en) * | 2015-02-06 | 2016-10-05 | 钜泉光电科技(上海)股份有限公司 | OFDM power-frequency synchronous power carrier communication and physical layer coded modulation method |
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