KR101891722B1 - Optical Wireless Communication(OWC) system - Google Patents

Abstract

The present invention relates to an optical wireless communication system, and more particularly, to an optical wireless communication system for transmitting data in an LED light source by constructing data packets through block coding and interleaving to reduce the number of packet transmissions, ≪ / RTI >
An optical wireless communication system according to the present invention includes: a data input unit receiving transmission data from an upper side or an outside; Arranging the input transmission data into m × n data blocks of m rows and n columns, adding i data bits for each row according to a predetermined coding rule, and coding the data into m × (n + i) data blocks A block coding unit; An interleaver configured to sequentially form stream data from the first column to the (n + i) th column using m × (n + i) data blocks coded by the block coding unit; A first controller for outputting a control signal for turning on / off an LED using the stream data configured in the interleaving unit; An LED light source unit for turning on / off the LED according to the control signal output from the first control unit;
An image sensor for detecting ON / OFF of the LED light source unit; A second controller for converting the ON / OFF pattern of the light source detected by the image sensor into digital data to form stream data; (N + i) -th data block in the (m + 1) th row and the (m + An interleaving unit; A block decoding unit decoding the data blocks formed by the deinterleaving unit into mxn data blocks applying predetermined decoding rules for each row; And a data output unit for outputting the m × n data blocks decoded by the block decoding unit to the top or the outside; .

Description

[0001] Optical Wireless Communication (OWC) system [

The present invention relates to an optical wireless communication system, and more particularly, to an optical wireless communication system for transmitting data in an LED light source by constructing data packets through block coding and interleaving to reduce the number of packet transmissions, ≪ / RTI >

A recent standardization work related to optical wireless communication (OWC), well known for the revision of the well-known Visible Light Communication (VLC), was conducted in the IEEE 802.15.7r1 task group. According to this revision, optical wireless communication (OWC) can be classified as Image Sensor Communications (ISC), High Rate PD Communications and Low Rate PD Communications. Among them, image sensor communication (ISC) is an optical wireless communication using an image sensor as a receiver.

Recently, as the number of smart phones equipped with high-performance image sensors has surged, interest in image sensor communication (ISC) has increased. In particular, attempts have been made to apply a rolling shutter camera equipped with an image sensor of a rolling shutter type to such an image sensor communication system.

Most rolling shutter cameras are electronic shutter cameras employing image sensors, which capture images for each row of image sensors combined in a plurality of rows and combine them to obtain images on a frame-by-frame basis.

1 is a diagram for explaining data transmission and frame gap data loss by a conventional rolling shutter camera. As shown in Fig. 1 (a), on / off images of the LEDs are sequentially written to each pixel in the image sensor over time. In order to communicate data, brightness information is extracted from the image to distinguish digital data 0 and 1, and the thickness of the pattern stored in the image sensor is changed according to the blinking speed of the LED. If the rolling shutter effect, in which brightness information is sequentially stored in each row in time in the image frame, is used, digital data according to the blinking of illumination can be received. FIG. 1 (b) shows an example of receiving data corresponding to several tens of bits in one image frame.

One of the problems with the image sensor communication method is that there exists a time gap, i.e., a frame gap (IFG), between each frame as shown in FIG. 1 (c). When data is stored in all the pixels of the image sensor, it takes time to transmit the data to the memory, reset the pixel, and prepare to store the brightness information of the next image. This frame gap (IFG) causes data to be lost. Since the LED, which is a transmitter, continuously transmits data regardless of the frame gap of the image sensor, which is a receiver, bit loss occurs in the frame gap.

In order to solve such a problem, conventionally, as shown in FIG. 2 (a), the same packet is transmitted twice, and an algorithm is constructed so that the image sensor takes two packets, which are not bit lost, of the two packets received. However, in this method, if the size of the packet is adjusted so that one of the two repeated packets necessarily avoids the frame gap, the data is guaranteed to be received. However, since the packet is repeatedly transmitted, the transmission speed is lowered do.

Patent Registration No. 1472583 Published Patent Application No. 2009-0016176 Published Patent Publication No. 2010-0135683 Patent Registration No. 1625534

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above problems of the prior art, and it is an object of the present invention to provide an optical wireless communication (OWC) using a rolling shutter camera equipped with an image sensor, Optical wireless communication system.

In addition, the present invention applies block coding and interleaving to transmission data in optical wireless communication (OWC) using a rolling shutter camera equipped with an image sensor, so that even if a data loss occurs in a frame gap, A method of data communication in a wireless communication system is provided.

An optical wireless communication system according to an embodiment of the present invention includes a data input unit receiving transmission data from an upper side or an outside side; A block coding unit for arranging the input transmission data into m × n data blocks of m rows and n columns and then coding the data into m × (n + i) data blocks according to a predetermined coding rule; An interleaver configured to sequentially form stream data from the first column to the (n + i) th column using m × (n + i) data blocks coded by the block coding unit; A control unit for outputting a control signal for turning on / off the LED using the stream data configured in the interleaving unit; And an LED light source unit for turning on / off the LED according to the control signal output from the control unit; .

An optical wireless communication system according to an embodiment of the present invention includes a preamble part for dividing the stream data formed in the interleaving part into packets of a predetermined bit unit and inserting a preamble bit for each packet; .

According to another aspect of the present invention, there is provided an optical wireless communication system including: an image sensor for sensing ON / OFF of an LED light source; A controller for converting the ON / OFF pattern of the light source detected by the image sensor into digital data to form stream data; A deinterleaving unit configured to sequentially arrange the stream data constituted by the control unit in the first column to the (n + i) th row in the m × (n + i) ; A block decoding unit decoding the data blocks formed by the deinterleaving unit into mxn data blocks applying predetermined decoding rules for each row; And a data output unit for outputting the m × n data blocks decoded by the block decoding unit to the top or the outside; .

An optical wireless communication system according to another exemplary embodiment of the present invention includes a de-preamble unit for detecting a preamble bit in a data strip configured in the controller and separating the preamble bit into packets of a predetermined bit unit; .

In the present invention, the deinterleaving unit may form an mx (n + i) data block using a packet of a predetermined bit unit divided in the de-preamble unit, and if a bit is lost in a packet of a predetermined bit unit, And inserts a preset arbitrary bit.

In the present invention, when an arbitrary bit preset by the loss is inserted into the mx (n + i) data block, the block decoding unit recovers the lost bit by applying a predetermined decoding rule, .

According to another aspect of the present invention, there is provided an optical wireless communication system including: a data input unit receiving transmission data from an upper side or an outside; Arranging the input transmission data into m × n data blocks of m rows and n columns, adding i data bits for each row according to a predetermined coding rule, and coding the data into m × (n + i) data blocks A block coding unit; An interleaver configured to sequentially form stream data from the first column to the (n + i) th column using m × (n + i) data blocks coded by the block coding unit; A first controller for outputting a control signal for turning on / off an LED using the stream data configured in the interleaving unit; An LED light source unit for turning on / off the LED according to the control signal output from the first control unit;

An image sensor for detecting ON / OFF of the LED light source unit; A second controller for converting the ON / OFF pattern of the light source detected by the image sensor into digital data to form stream data; (N + i) -th data block in the (m + 1) th row and the (m + An interleaving unit; A block decoding unit decoding the data blocks formed by the deinterleaving unit into mxn data blocks applying predetermined decoding rules for each row; And a data output unit for outputting the m × n data blocks decoded by the block decoding unit to the top or the outside; .

According to another aspect of the present invention, there is provided an optical wireless communication system including: a preamble part for dividing the stream data formed in the interleaving part into packets of a predetermined bit unit and inserting a preamble bit for each packet; And a de-preamble unit for detecting a preamble bit in the data strip configured by the second controller and dividing the preamble bit into packets of a predetermined bit unit; .

In the present invention, the deinterleaving unit may form an mx (n + i) data block using a packet of a predetermined bit unit divided in the de-preamble unit, and if a bit is lost in a packet of a predetermined bit unit, And inserts a preset arbitrary bit.

In the present invention, when an arbitrary bit preset by the loss is inserted into the mx (n + i) data block, the block decoding unit recovers the lost bit by applying a predetermined decoding rule, .

According to the present invention, in the optical wireless communication (OWC) using the rolling shutter camera equipped with the image sensor, the transmission unit can send the packet only once, and as a result, the data transmission speed can be improved.

In addition, according to the present invention, even if data loss occurs in a frame gap using block coding and interleaving in transmission data in optical wireless communication (OWC), the receiver can recover original data.

1 is a view for explaining data transmission and data loss in a frame gap by a rolling shutter camera according to the related art.
2 is a view for explaining an example of transmitting the same packet twice in the optical wireless communication according to the related art.
3 is a configuration diagram of an optical wireless communication system according to the present invention.
4 is a diagram illustrating a process of data transmission by block coding and interleaving in an optical wireless communication system according to an embodiment of the present invention.
5 is a diagram illustrating a process of data reception by block coding and interleaving in an optical wireless communication system according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; may be "connected," "coupled," or "connected. &Quot;

3 is a configuration diagram of an optical wireless communication system according to the present invention.

3, the optical wireless communication system 100 according to the present invention includes a transmitting unit 110 for transmitting data and a receiving unit 120 for receiving data from the transmitting unit 110. Referring to FIG. The transmission unit 110 includes a data input unit 111, a block coding unit 112, a bit interleaving unit 113, a preamble unit 114, a first control unit 115 and an LED light source unit 116, A deinterleaving unit 124, a block decoding unit 125 and a data output unit 126. The image processing unit 121 includes an image sensor 121, a second control unit 122, a de-preamble unit 123,

The data input unit 111 receives transmission data from the upper side or the outside. The transmission data is data to be transmitted from the transmission unit 110 to the reception unit 120 in the optical wireless communication system 100. The transmission data is input as digital data to the data input unit 111 in the form of stream data.

The block coding unit 112 forms block data having a predetermined column and a row using the stream data input to the data input unit 111 and performs block coding.

This block coding is a process of encrypting data in order to facilitate recovery when a data bit is lost or an error occurs due to data transmission and reception. Generally, in a data communication, bits constituting data to be transmitted are used, It takes a method of constructing a data block by generating additional bits and adding them.

The block coding unit 112 first arranges the transmission data input through the data input unit 111 into m × n data blocks of m rows and n columns and adds i data bits for each row according to a predetermined coding rule , And then coded into mx (n + i) data blocks.

For example, assuming that the block coding unit 112 arranges the transmission data into 8x4 data blocks, when 32-bit data is input as shown below, the data block is divided into 8 rows in total, such as B, Data.

32-bit data: 11110000111100001111000011110000

Data block B:

When the mxn data block is configured, the block coding unit 112 applies a predetermined coding rule so that the receiver can restore the original data even if an error occurs in any one of the bits constituting each row Insert additional bits.

The error-correcting coding rule applicable to the block coding unit 112 is (7,4) Hamming code scheme. This method means that 4 bits out of 7 bits in one row are the actual data bits and the remaining 3 bits are the bits for detecting and recovering the error. The block coding method using the (7, 4) And is not described in the present invention because it is a known technique.

In the case of the data block B constructed in the above example, since 4 bits are actual data for each row (7, 4), 3 bits are added to each row by coding using the Hamming code method, (4 + 3) data blocks.

The interleaving unit 113 sequentially constructs stream data from the first column to the (n + i) th column by using the m × (n + i) data blocks coded by the block coding unit 112.

Interleaving is one of techniques for distributing intensive bit errors in a wireless channel environment where intensive bit errors are likely to occur. In particular, in the case of block interleaving, bits are arranged in the same row in the actual data by transmitting data by changing columns and rows of data blocks So that even if bits in the middle of the data due to instantaneous noise are lost, the influence is dispersed in several rows.

The interleaving unit 113 is configured to perform the block interleaving. The interleaving unit 113 constructs stream data in units of columns, and transfers the transmission data, which are input from the data input unit 111 and constitute a block on a row basis, to be transmitted.

For example, when the interleaving unit 113 interleaves the data block B described in the above example, the stream data is configured sequentially from 8 bits in the first column to 8 bits in the fourth column so that the following stream data is configured.

Stream data: 10101010101010101010101010101010

The preamble section 114 divides the stream data formed by the interleaving section 113 into packets of a predetermined bit unit, and inserts a preamble bit for each packet.

A preamble bit is a signal used to synchronize the transmission timing between two or more systems in a network communication, and is a bit that enables to correctly interpret the start of information transmission.

That is, when data having a certain length is continuously transmitted, it is possible to distinguish the beginning of each data.

For example, if the preamble bit to be inserted is 1100 and the 32-bit stream data used in the example of the interleaving unit 113 is to be transmitted in a 16-bit unit packet, the final stream data in which the preamble bit is inserted is 24 Bit.

Final stream data: 1100 1010101010101010 1100 1010101010101010

In the above stream data, the underlined portion is a preamble bit, and the receiving side recognizes the displayed portion as a preamble bit so that each packet can be distinguished.

The reason for distinguishing the packets is to distinguish how many bits are lost in a certain packet when loss of data occurs in transmission, and to continuously transmit data of several tens of hundreds of bits without dividing the packet into a certain length , It is impossible to check which part is lost even if a bit loss occurs in the middle.

The stream data to which the preamble bit is added is converted into a control signal for turning on / off the LED light source through the first control unit 115.

For example, the first control unit 115 converts digital data "0" into a signal for turning off the LED and outputs the converted signal, and "1"

The LED light source unit 116 includes at least one LED light source, receives the signal output from the first control unit 115, and turns on / off the LED light source.

The configuration described above corresponds to the transmitter 110 and the receiver 120 receives the ON / OFF pattern of the LED light source 116 of the transmitter 110 and generates data.

First, the image sensor 121 senses the ON / OFF of the LED light source of the LED light source unit 116.

The ON / OFF pattern of the LED light source sensed in this manner is converted into digital data through the second control unit 122.

For example, the second control unit 122 can convert the ON pattern into the digital data "1" and the OFF pattern into the digital data "0", and confirms the continuous ON / OFF pattern and constructs it as stream data.

The pre-preamble section 123 detects a preamble bit in the stream data formed in the second control section 122 and divides the preamble bit into packets of a predetermined bit unit.

The pre-preamble section 123 detects a preamble bit inserted in the preamble section 114, and divides the data before the preamble bit is inserted into a unit of a predetermined length.

The deinterleaving unit 124 demultiplexes the stream data into m rows and (m + (n + i) th data blocks in the (n + i) To the (n + i) th column.

At this time, when the lost bit occurs in the packet of the predetermined bit unit, the deinterleaving unit 124 inserts a predetermined bit and configures the data block while keeping the length of the packet constant.

The deinterleaving unit 124 performs a function of rearranging the data transmitted in the interleaving unit 113 of the transmitting unit 110 by exchanging columns and rows in the original order again. Since the unit data is data in which streams are arranged, the deinterleaving unit 124 forms data blocks by arranging the data arranged in a stream in units of columns.

For example, if the packet in the bit unit divided by the de-preamble unit 123 is as follows,

Packet 1: 00001111

Packet 2: 00110011

Packet 3: 01010101

Packet 4: 11111111

If an 8x4 data block is constructed, the following configuration is made.

8 x 4 data blocks:

In the 8x4 data block formed by the deinterleaving unit 124, Packet 1 input as stream data is configured in the first column, Packet 2 is configured in the second column, Packet 3 is configured in the third column, and Packet 4 is configured in the fourth column, 4 data blocks are formed.

At this time, if a bit loss due to a frame gap occurs in any one of the packets, a data block of a predetermined size can not be formed and block decoding to be described later can not be performed.

Accordingly, when the bit loss occurs, the deinterleaving unit 124 forms a data block by inserting an arbitrary bit and then restores an arbitrary bit to a normal bit through subsequent block decoding.

The block decoding unit 125 decodes m × (n + i) data blocks constituted by the de-interleaving unit 124 into m × n data blocks by applying a predetermined decoding rule for each row.

Even if an error occurs in any one of the bits constituting each row in the block coding unit 112 described above, additional bits are inserted by applying a predetermined coding rule so that the receiver can restore the original data, The decoding unit 125 performs decoding so as to restore the original data using the bit inserted by applying the predetermined decoding rule.

That is, the block decoding unit 125 recovers error bits among (n + i) bits by using a predetermined decoding rule using i bits added for each row for m rows, and then removes the added bits And extracts the data block mxn that was previously configured before performing the block coding in the block coding unit 112. [

For example, if the (7, 4) Hamming coding rule is applied in the block coding unit 112, the block decoding unit 125 sets the decoding rule to 7 , 4) Block decoding is performed by applying the Hamming decoding rule.

When the data block mxn is extracted through the block decoding unit 125, the data output unit 126 outputs the extracted data block to an upper or an external device.

At this time, the data output unit 126 outputs stream data in the form of stream data to an upper or an external apparatus.

Even if a data loss due to an interframe gap occurs in the receiver 120 through the configuration of the optical wireless communication system 100, the data is dispersed into each packet through an interleaving technique and restored by block coding and decoding to transmit normal data It becomes possible to receive the data.

The process of data transmission / reception by block coding and interleaving will be described with reference to a detailed example.

4 is a diagram illustrating a process of data transmission by block coding and interleaving in an optical wireless communication system according to an embodiment of the present invention.

Referring to FIG. 4, it can be seen that a total of 32 bits of data are input through the data input unit 111 in the block coding and interleaving transmission process according to the present invention.

The inputted 32-bit data is composed of 8 × 4 data blocks 1 10 by the block coding unit 112 and then composed of 8 × 7 data blocks 2 by the predetermined coding rule.

In the example of FIG. 4, the coding rule is (7, 4) Hamming coding, and the four bits d1 to d4 from the right side of the data block 2 20 are the actual data bits and the left three bits p1 to p3 ) Is a bit added through Hamming coding.

An additional bit value is generated by a combination of d1 to d3 bits for each row, and each bit value is calculated by Hamming coding rule.

The method of adding a bit through the Hamming coding is only an embodiment of the present invention. In another embodiment, the number of added bits, the position of added bits in actual data bits, and the like may be different according to another coding scheme.

The interleaver 113 for the data block 2 (20) configured as described above constructs the data block 3 (30) by interchanging the columns and the rows, and then arranges each row successively to produce the stream data.

The stream data generated by the interleaving unit 113 is composed of a transmission packet 40 by dividing the stream data into 8-bit packets in the preamble unit 114 and inserting 4-bit preamble bits of 4 bits in the left side of each packet.

The transmission packet 40 in which 4 bits are added to the 8-bit data is composed of a total of 7 individual packets, and the transmission packet 40 having a total of 84 bits is transmitted as the LED ON / OFF control signal through the first control unit 115 And the LED light source unit 116 is turned on / off.

5 is a diagram illustrating a process of data reception by block coding and interleaving in an optical wireless communication system according to an embodiment of the present invention.

5, the ON / OFF pattern of the LED light source received through the image sensor 121 is received by the second controller 122 as a digital signal Converted into a total of 81 bits of digital data.

The de-preamble section 123 detects the "0110" preamble bit inserted in the preamble section 114 and distinguishes seven reception packets 50 of 8-bit size.

It is confirmed that the fourth packet among the seven received packets 50 has five data bits, which indicates that three bits are lost due to the interframe gap of the receiving unit 120. [

Next, in the deinterleaving unit 124, seven received packets 50 of 8-bit units arranged in order are arranged vertically from the first column to the seventh column to form an 8 × 7 data block 4 (60). At this time, The three bits of the lost bit in the fourth packet of the data block 50 become the d4 position of the sixth row, the seventh row and the eighth row of the data block 4 (60), and an arbitrary bit "1 & Data block 4 (60).

Next, the block decoding unit 125 extracts the data of the actual data d1 to d4 by applying the decoding rule of the (7, 4) Hamming code to each row of the data block 4 (60) When decoding the 6th row, the 7th row, and the 8th row of the data block 4 (60), the bit "1" of the d4 that has been lost and arbitrarily inserted is stored in the data block 5 (70) Quot; 0 ", which is < / RTI >

The data block 5 70 reconstructed through the block decoding unit 125 is identical to the data block 1 10 constructed by the block coding unit 112 in FIG. It can be seen that data is restored normally through block coding and interleaving even in the case where 3 bits are lost.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. Furthermore, the terms "comprises", "comprising", or "having" described above mean that a component can be implanted unless otherwise specifically stated, But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: optical wireless communication system 110:
111: Data input unit 112: Block coding unit
113: Interleaving section 114: Preamble section
115: first control unit 116: LED light source unit
120: Receiver 121: Image sensor
122: second control unit 123: de-preamble unit
124: deinterleaving unit 125: block decoding unit
126: Data output section 10: Data block 1
20: data block 2 30: data block 3
40: transmission packet 50: received packet
60: data block 4 70: data block 5

Claims (10)

delete delete An image sensor for detecting ON / OFF of the LED light source;
A controller for converting the ON / OFF pattern of the light source detected by the image sensor into digital data to form stream data;
A deinterleaving unit configured to sequentially arrange the stream data constituted by the control unit in the first column to the (n + i) th row in the m × (n + i) ;
A block decoding unit decoding the data blocks formed by the deinterleaving unit into mxn data blocks applying predetermined decoding rules for each row; And
A data output unit for outputting the m × n data blocks decoded by the block decoding unit to the top or the outside; Lt; / RTI >
A de-preamble unit for detecting a preamble bit in the data strip configured by the controller and separating the preamble bit into packets of a predetermined bit unit; Further comprising:
Wherein the deinterleaving unit forms an mx (n + i) data block using a packet of a predetermined bit unit divided in the de-preamble unit and, when a bit lost in a packet of a predetermined bit unit occurs, Of the optical signal. delete delete The method of claim 3,
The block decoding unit may recover the lost bit by applying a predetermined decoding rule when an arbitrary bit predetermined by the loss is inserted in the mx (n + i) data block, and then extract the mxn data block Wireless communication system. A data input unit for receiving transmission data from an upper side or an outside side;
Arranging the input transmission data into m × n data blocks of m rows and n columns, adding i data bits for each row according to a predetermined coding rule, and coding the data into m × (n + i) data blocks A block coding unit;
An interleaver configured to sequentially form stream data from the first column to the (n + i) th column using m × (n + i) data blocks coded by the block coding unit;
A first controller for outputting a control signal for turning on / off an LED using the stream data configured in the interleaving unit;
An LED light source unit for turning on / off the LED according to the control signal output from the first control unit;
An image sensor for detecting ON / OFF of the LED light source unit;
A second controller for converting the ON / OFF pattern of the light source detected by the image sensor into digital data to form stream data;
(N + i) -th data block in the (m + 1) th row and the (m + An interleaving unit;
A block decoding unit decoding the data blocks formed by the deinterleaving unit into mxn data blocks applying predetermined decoding rules for each row; And
A data output unit for outputting the m × n data blocks decoded by the block decoding unit to the top or the outside; / RTI >
Wherein the deinterleaving unit forms an mx (n + i) data block using a packet of a predetermined bit unit divided in the de-preamble unit, and when a bit lost in a packet of a predetermined bit unit occurs, Bit < / RTI > 8. The method of claim 7,
A preamble part for dividing the stream data formed by the interleaving part into packets of a predetermined bit unit and inserting a preamble bit for each packet; And
A de-preamble part for detecting a preamble bit in the data strip configured in the second controller and separating the preamble bit into packets of a predetermined bit unit; Further comprising: delete 8. The method of claim 7,
The block decoding unit may recover the lost bit by applying a predetermined decoding rule when an arbitrary bit predetermined by the loss is inserted in the mx (n + i) data block, and then extract the mxn data block Wireless communication system.

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