KR20200071376A - Data compression and decompression method and mobile communication apparatus using the same - Google Patents

Abstract

Disclosed are data compression and decompression methods thereof and a mobile communication repeater to which the methods are applied. According to an embodiment of the present invention, a data compression method comprises: a compressing step of compressing a first bit string obtained by converting a mobile communication signal into digital data to generate compressed data of a second bit string; and a framing step of generating a frame including N samples of the second bit string (where N is a natural number of 2 or more). The compressing step may include variably compressing the number of bits of the second bit string of each sample in one frame.

Description

Data compression and decompression method and mobile communication device to which they are applied

The present invention relates to a data compression and decompression method and a mobile communication device to which they are applied, and more specifically, a data compression and decompression method having a variable number of compression bits for each sample including a plurality in one frame, and It relates to a mobile communication device to which they are applied.

Generally, in a mobile communication system, a mobile communication signal is transmitted from a base station to a terminal or a terminal to a base station. However, depending on the region, there may be a shadow region where the signal cannot reach, and a repeater is installed and operated to solve the shadow region.

These repeaters are variously classified into optical repeaters, frequency converting repeaters, frequency non-converting repeaters, microwave (M/W) repeaters, laser repeaters, etc., depending on the relay method, and are classified into digital repeaters and analog repeaters according to the operation method. It may be.

Among them, the digital repeater is composed of a main hub unit (MHU) that transmits and receives signals to and from a base station, and a remote optic unit (ROU) that is installed in a shaded area while transmitting and receiving signals to and from a user terminal. At this time, these units convert the analog signal received from the base station or the user terminal into a digital signal, and then transmit the converted digital signal to a counterpart unit through a transmission path (for example, optical fiber, etc.). In addition, the digital signal transmission can be applied to other mobile communication devices. Hereinafter, the repeater and other mobile communication devices are referred to as “mobile communication devices”.

Meanwhile, with the development of mobile communication technology, it is required to utilize radio resources having a higher frequency band and a wider frequency bandwidth. However, there is a limit to the data rate that a transmission path of a mobile communication device can transmit. To overcome these limitations, data compression technology is applied in the digital conversion process for digital signal transmission.

Conventionally, data compression technology applied to digital signal transmission of a mobile communication device can be roughly divided into three types. That is, unnecessary sample data can be removed through downsampling. In addition, in the quantization process, non-linear quantization and block scaling methods can be applied to increase quantization efficiency to minimize the number of quantization bits. In addition, a digital transmission technique may be applied to digital data derived after quantization to reduce the required transmission capacity. For example, in the case of a bit string in which a specific pattern is repeated, the required transmission capacity can be reduced by expressing the number of repeated bits from the MSB (Most Significant Bit) through a predetermined number of bits.

This conventional data compression technique compresses to have the same number of compressed bits (ie, the number of bits after compression is applied) for each of a plurality of samples included in one transmission frame. However, among the samples, even if a bit number less than a fixed number of bits is used, there may be a probability that there is no loss of information or a sample with little effect (hereinafter referred to as “highly compressible sample”). There is a problem that can not adaptively cope with.

The technical problem to be solved by the present invention is to provide a data compression and decompression method operating to have a variable number of compressed bits for each sample, and a mobile communication device to which they are applied.

In order to solve the above technical problem, a data compression method according to an embodiment of the present invention is a compression step of compressing a first bit stream that converts a mobile communication signal into digital data to generate compressed data of a second bit stream. ; And a framing step of generating a frame including N samples of the second bit string (where N is a natural number greater than or equal to 2), and the compressing step includes determining the number of bits of the second bit string of each sample in one frame. And variably compressing.

Each of the N bits and the total number of bits of the one frame (where M is a natural number of 2 or more) may be fixed.

In the framing step, when the total number of bits according to N samples in one frame is greater than the number of M, the number of second bit strings of the last sample is reduced, and the total number of bits according to N samples in the one frame is the In the case of less than M, the step of inserting an additional bit after the last sample may be included.

The compressing may include allocating a first predetermined number of consecutive bits (pattern bits) of the first bit string to the first area of the second bit string; Counting the number (n) of bits (pattern length bits) in which the pattern bits are repeated (where n is a natural number greater than or equal to 1) in the bit strings after the pattern bits in the first bit string; And assigning to the second area of the second bit string as a binary number (compressed bit) for the counted n.

In the data compression method according to an embodiment of the present invention, bits (remaining bits) after the next bit of the pattern length bit in the first bit string are stored in the third area of the second bit string according to the size of n. The step of allocating may be further included.

In the step of allocating to the third area, when n is smaller than the reference value (η), the residual bits are set to a predetermined number (C) (however, C is a natural number of 1 or more), where n is the reference value ( η) in a larger case, setting the residual bits to a number smaller than C.

The data decompression method according to an embodiment of the present invention includes: a deframing step of classifying each sample in one frame including N samples of a first bit stream that is compressed data (where N is a natural number of 2 or more); And a decompression step of decompressing the first bit sequence to generate digital data of the second bit sequence, wherein the decompression step includes a first bit sequence of each sample having a variable number of bits in one frame. And decompressing.

The total number of bits of the N frames and the M frames (where M is a natural number of 2 or more) is different from each other, but may be fixed.

The deframing step may include classifying each sample in a bit stream excluding additional bits inserted after the last sample when the total number of bits according to N samples in the one frame is less than the M pieces. .

The decompression step may include, in the first bit sequence, dividing an area corresponding to the first predetermined number of consecutive bits (pattern bits), an area corresponding to the compressed bits, and an area corresponding to the remaining bits; And allocating the pattern bits to the first area of the second bit string, and repeatedly allocating the pattern bits by the number (n) corresponding to the binary number of the compressed bits to the second area of the second bit string. can do.

The method for decompressing data according to an embodiment of the present invention includes allocating a bit of a binary number different from the last bit when repeating the compressed bit by n+1 to a third area of the second bit string; And allocating the remaining bits to the fourth area of the second bit string.

In the step of allocating to the fourth region, when the n is smaller than the reference value (η), the remaining bits of a predetermined number (C) (where C is a natural number of 1 or more) are allocated to the fourth region, When the reference value (η) is large, the method may include allocating the residual bits only to a number smaller than C to the fourth region.

A mobile communication device according to an embodiment of the present invention is a mobile communication device that transmits a mobile communication signal, and a compression unit compressing a first bit string in which the mobile communication signal is converted into digital data to generate compressed data in a second bit string. ; And a frame processing unit for generating a frame including N samples of the second bit stream (where N is a natural number of 2 or more), and the compression unit varies the number of bits of the second bit stream of each sample in one frame. Compresses.

A mobile communication device according to an embodiment of the present invention is a mobile communication device that transmits a mobile communication signal, and each sample in one frame including N samples of a first bit stream that is compressed data (where N is a natural number of 2 or more). Frame processing unit to classify; And a decompression unit that decompresses the first bit stream to generate digital data of the second bit stream, and the decompression unit decompresses the first bit stream of each sample whose number of bits is variable in one frame. do.

The present invention as described above, by operating to have a variable number of compression bits for each sample, it is possible to adaptively compress and decompress data according to the characteristics of data for each sample, so digital optical transmission data in a wireless access network By compressing more efficiently, the required optical transmission capacity can be minimized, and accordingly, the cost of the digital optical transmission device can be minimized.

In addition, according to the present invention, information other than wireless service data, for example, control information and other types of wired services can be simultaneously transmitted using the same optical transmission device, thereby improving network operation efficiency.

1 is a configuration diagram for schematically explaining a mobile communication repeater of an embodiment of the present invention.
2 is an exemplary diagram for explaining a signal transmission process of a mobile communication repeater according to an embodiment of the present invention.
3 shows an example of a frame structure (downlink).
4 is an exemplary diagram for showing a compression principle applicable during a signal transmission process of a mobile communication repeater according to an embodiment of the present invention, and shows a first bit stream (BS1) to a third bit stream (BS3).
5 is a flowchart for explaining the compression step of FIG. 2 in more detail.
6 is an exemplary view for explaining a signal reception process of the second device of the mobile communication repeater according to an embodiment of the present invention.
7 is a flowchart for explaining the decompression step of FIG. 6 in more detail.

In order to fully understand the configuration and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be implemented in various forms and various changes can be made. However, the description of the present embodiment is provided to complete the disclosure of the present invention, and to fully inform the scope of the invention to those skilled in the art to which the present invention pertains. In the accompanying drawings, the components are enlarged and enlarged than actual sizes for convenience of description, and the ratio of each component may be exaggerated or reduced.

Terms such as'first' and'second' may be used to describe various components, but the components should not be limited by the above terms. The above terms may be used only for the purpose of distinguishing one component from other components. For example, without departing from the scope of the present invention, the'first component' may be referred to as a'second component', and similarly the'second component' may also be referred to as a'first component'. You can. In addition, a singular expression includes a plural expression unless the context clearly expresses otherwise. Terms used in the embodiments of the present invention may be interpreted as meanings commonly known to those skilled in the art unless otherwise defined.

Hereinafter, a mobile communication device and a data compression and decompression method thereof according to an embodiment of the present invention will be described in detail with reference to the drawings.

A mobile communication device according to an embodiment of the present invention is a device for transmitting a mobile communication signal, and may be a repeater or a base station, but is not limited thereto. However, hereinafter, for convenience of description, a case where the mobile communication device according to an embodiment of the present invention is a repeater will be described.

1 is a configuration diagram for schematically explaining a mobile communication repeater of an embodiment of the present invention.

A mobile communication repeater according to an embodiment of the present invention, as shown in Figure 1, as a system for relaying a signal between the base station 2 and the user terminal 3, the first device 10 and the second device ( 20).

The first device 10 is a device that transmits and receives signals to and from the base station 2, and may be a master hub unit (MHU). Also, the second device 20 is a device that transmits and receives signals to and from the user terminal 3 and may be a remote optical unit (ROU). At this time, an analog signal is used as an interface to the base station 2 or the user terminal 3, and the mobile communication repeater of the present invention digitizes the analog signal and transmits the signal to the distributed unit through the transmission line 30. It can be configured to. For signal transmission through the transmission line 30 of the first device 10 and the second device 20, various optical elements such as small form-factor pluggable (SFP) terminals may be employed, but are omitted for convenience of explanation I will do it.

The first device 10 digitally samples the input signal, which is an analog signal received from the base station 2, to generate digital data, compresses the generated digital data according to an embodiment of the present invention, and then compresses the compressed data into an optical fiber. It may be transmitted to the second device 20 using a transmission line 30 such as.

The second device 20 decompresses the compressed data received from the first device 10 into original digital data, converts the decompressed digital data into an analog signal, and transmits it to the user terminal 3.

Similarly, the second device 20 digitally samples the input signal, which is an analog signal received from the user terminal 3, to generate digital data, compresses the generated digital data according to an embodiment of the present invention, and then compresses it. Data may be transmitted to the first device 10 using the transmission line 30.

The first device 10 decompresses the compressed data received from the second device 20 into original digital data, and converts the decompressed digital data into an analog signal and transmits it to the base station 2.

Specifically, the first device 10 and the second device 20, as shown in Figure 1, the frequency conversion unit (11, 21), the base band processing unit (12, 22), AD (Analog to Digital) Conversion unit (13, 23), DA (Digital to Analog) conversion unit (14, 24), compression unit (15, 25), decompression unit (16, 26), frame processing unit (17, 27) and transmission unit ( 18, 28), respectively. Hereinafter, for convenience of explanation, a'first' is added to the front of the name of each detailed configuration included in the first device 10, and a'second' is added to the front of the name of each detailed configuration included in the second device 20. I will add'.

On the other hand, if not a repeater, the mobile communication device according to an embodiment of the present invention may be a first device 10 or a second device 20, the first device 10 or the second device 20 described later ). However, even in this case, the mobile communication device according to an embodiment of the present invention includes at least the compression units 15 and 25 and the decompression unit 16 among components of the first device 10 or the second device 20 to be described later. , 26) and the frame processing unit 17. For example, in the case of optical transmission between a base station and a long-distance radio equipment, a separate ADC/DAC conversion may not be performed because the baseband signal of OFDM modulated by the base station is provided immediately.

The detailed configuration of the first device 10 and the second device 20 will be described with reference to the following signal transmission process.

2 is an exemplary diagram for explaining a signal transmission process of a mobile communication repeater according to an embodiment of the present invention.

First, a signal from the base station 2 to the first device 10 of the mobile communication repeater, from the first device 10 to the second device 20, and from the second device 20 to the user terminal 3, respectively The downlink process in which A is transmitted will first be described.

The first frequency converter 11 may convert an input signal of a radio frequency (RF) band received from the base station 2 into a signal of an intermediate frequency (IF) band (S10).

The first baseband processor 12 may convert the IF band signal converted by the first frequency converter 11 into a baseband band signal (S20 ). At this time, the converted baseband band signal may include an I (In-phase) signal and a Q signal (Quadrature-phase).

The first AD conversion unit 13 may convert the baseband signal for each sample converted by the first baseband processing unit 12 into digital data through digital sampling (S30). In this case, a bit stream of digital data generated for each sample is referred to as a'first bit stream (BS1)'. That is, the first bit stream BS1 is a bit stream for one sample.

The first bit stream BS1 may include I bits (I0, I1, I2, ...) in which the I signal is digitally sampled, and Q bits (Q0, Q1, Q2, ...) in which the Q signal is digitally sampled, and I Bits I0, I1, I2, ... and Q bits (Q0, Q1, Q2, ...) may be cross-mixed bit sequences in sequence.

3 shows an example of a frame structure (downlink).

The first compression unit 15 checks the characteristics of the first bit stream BS1 for each sample generated by the first AD converter 13 and compresses the first bit stream BS1 for each sample according to the identified characteristics. It can be (S40). In this case, the bit stream of the compressed data is referred to as a'second bit stream (BS2)', and a sample of the compressed data is called a'sample (CD)'.

When determining the characteristics of the first bit stream BS1 of one sample, the first compression unit 15 may perform a determination to reduce the number of bits with little loss. For example, when the first bit stream (BS1) of one sample is 14 bits in which a specific pattern is continuously repeated, lossless compression may be possible with only about 5 to 6 bits, and in this case, when sampling an OFDM signal Probably it will happen. That is, the first compression unit 15 performs compression by expressing the number of repeated bits from the MSB (Most Significant Bit) through a predetermined number of bits when a specific pattern is repeated in the first bit stream BS1. can do. A more detailed description of this will be described later with reference to FIGS. 4 and 5.

Meanwhile, each sample CD includes one second bit string BS2, and the number of bits of the second bit string BS2 of each sample CD is variable. That is, the compression rates of the first sample CD1 and the other second sample CD2 may be the same or different from each other, and accordingly, the second bit stream BS2 of the first sample CD1 and the second sample CD2. The number of bits may be the same or different from each other.

The first frame processing unit 17 may generate a frame including compressed data CB generated by the first compression unit 15 (S50). That is, the first frame processor 17 may function as a framer. At this time, the first frame processing unit 17 may generate a frame such that N samples (where N is a natural number of 2 or more) are included in one frame. Accordingly, the number of bits of the second bit stream BS2 of each sample CD in one frame is variable.

However, for synchronization between each frame according to the transmission standard, each of the M bits, which is the total number of bits of N frames and one frame (where M is a natural number of 2 or more), may be fixed. That is, the first frame and the other second frame have the same total number of M bits, and include the same N samples (CD), but the number of bits of the second bit stream (BS2) of each sample (CD) is different. Can

At this time, the frame may further include a header including identification information of a transmission destination and information about the size of a compressed bit, in addition to each sample CD. Further, the header may further include information on the position and number of pattern bits, and when there is no information on this, the pattern bits may be regarded as the first two bits.

The specific average number of compressed bits that can maximize the compression rate with little performance degradation can be determined experimentally by the statistical characteristics of the analog RF signal. Since the average number of samples of N samples (CD) in one frame should almost match the average number of compressed bits, the N value should be set to a sufficiently large value. For example, if the value of N is set to about 100, the standard deviation of the sample mean is less than 0.1 bits, and if the number of samples N is greater than about 50, the approximate normal distribution is followed and statistical characteristics can be analyzed. For reference, when N = 100, the probability that the value of the sample average exceeds the average compressed bit count by 0.2 bits or more is less than 0.23%.

The total number of bits in one frame is the number of bits in the header plus M. At this time, M = N ⅹ [average number of bits of the second bit stream (BS2)] may be. To keep the sampling timing synchronized, the total number of bits in the frame can always be fixed. That is, the first frame processing unit 17 may perform a task of setting the total number of bits according to N samples CD in one frame, that is, the sum of the number of bits of the N samples CD to M.

As in the second example of FIG. 3, when N sample data inevitably exceeds one frame size M, a low significant bit (LSB) of the corresponding last sample (CD#N) may be removed. That is, when the total number of bits according to N samples (CD) in one frame is greater than M, the first frame processing unit 17 corresponds to the LSB of the second bit stream (BS2) of the last sample (CD#N). Can be reduced by the number.

Conversely, as in the third example of FIG. 3, if all the N samples (CDs) are configured and the total number of bits is smaller than one frame size M, the additional bits UD may be padded to match the frame size. That is, when the total number of bits according to N samples (CD) in one frame is less than M, the first frame processing unit 17 adds a small number of additional bits (UD) after the last sample (CD#N). Can be inserted in For example, OAM control data or other wired service data may be applied as an additional bit (UD).

4 is an exemplary diagram for showing a compression principle applicable during a signal transmission process of a mobile communication repeater according to an embodiment of the present invention, and shows a first bit stream (BS1) to a third bit stream (BS3).

Referring to FIG. 4, the first bit stream BS1 of one sample CD may be composed of the pattern bit PB and the remaining bit stream RBS, which is a bit stream after the pattern bit excluding the pattern bit.

The pattern bit may be the first predetermined number of consecutive bits in the first bit stream BS1. For example, the pattern bit may be two consecutive bits, and in this case, may include I0 and Q0. When the pattern bits are two consecutive bits, the number of corresponding cases is [0, 0], [0, 1], [1, 0], [1, 1], and there may be four sets. However, this is an example, and the number of pattern bits is not limited thereto.

The second bit stream BS2 includes an area occupied by the pattern bit PB, an area occupied by the compressed bit CB which is a compressed bit among the remaining bit stream RBS, and an uncompressed area among the remaining bit stream RBS. It can be seen that it includes an area occupied by the remaining bits RB. However, the size of the area occupied by the residual bit RB may be determined by determining the size of the area occupied by the pattern bit PB, the area occupied by the compression bit CB, and the overall target compression size. have.

5 is a flowchart for explaining the compression step of FIG. 2 in more detail.

The first compression unit 15 may allocate the pattern bit PB, which is the first predetermined number of consecutive bits of the first bit string B1, to the first area of the second bit string BS1.

In order to determine the area occupied by the compression bit CB, the first compression unit 15 repeats the pattern bit PB in the remaining bit stream RBS after the pattern bit PB of the first bit stream BS1. The number n of pattern length bits (PLB), which is the number of bits (where n is a natural number of 1 or more), can be counted. Thereafter, the first compression unit 15 may allocate a binary number for the number n of counted pattern length bits to the second area of the second bit stream BS2 as the compression bit CB.

Thereafter, in order to determine the area occupied by the residual bit RB, the first compression unit 15 is the next bit NB of the pattern length bit PLB in the first bit stream BS1 ('a' in FIG. 4) The bit indicated by) may be omitted and the remaining bit RB, which is a bit after the next bit NB, may be allocated to the third area of the second bit stream BS2 according to the size of n. In this case, the omission of the next bit (NB) is because the next bit (NB) corresponds to a bit of a binary number that is always different from the last bit of the pattern length bit (PLB). to be. In addition, since the residual bit RB may correspond to the LBS, the residual bit'(RB') allocated to the third area may include only a part of the residual bit RB.

However, when determining the area occupied by the residual bit RB, the first compression unit 15 may use a certain number of residual bits'(RB') when n is smaller than the reference value η (C) (however, C is 1 or more). This means that when n is smaller than the reference value, it means that as few bits are compressed in the first bit stream (BS1), performance deterioration can be reduced by securing more residual bits'(RB'). to be.

On the other hand, when n is greater than or equal to the reference value η, the first compression unit 15 may set the residual bit'(RB') to a number smaller than C ( eg, C-1). This is because when n is larger than the reference value, that means that as many bits are compressed in the first bit stream BS1 as possible, even if the residual bit'(RB') is reduced, there is little possibility of performance degradation. That is, when the n value is sufficiently large, the pattern bit PB and the compressed bit CB of the second bit stream BS2 can be used to express a sufficiently large number of bits from the MSB or, in some cases, all bits. Even if the area occupied by the residual bit'(RB') located at the side is partially reduced, there is little performance degradation.

FIG. 4 shows a case in which the first bit stream BS1 having a length of 15 bits is compressed into a second bit stream B2 of 9 bits. That is, in the second bit string B2, the area occupied by the pattern bit PB is allocated 2 bits, the area occupied by the pattern length bit PB is allocated 4 bits, and the remaining bit'(RB') occupies. The area was allocated with 3 bits. At this time, if n, which is the number of bits of the pattern length bit PLB, has a value smaller than a preset threshold value η, the bit length of the region occupied by the remaining bits'(RB') is left as C. On the other hand, if n has a value greater than or equal to η, the bit length of the region occupied by the residual bits'(RB') is reduced to C-1. However, if the remaining bit' (RB') to fill in the area occupied by the remaining bit'(RB') is insufficient, 0 or an arbitrary value may be allocated to the corresponding area.

Thereafter, the first transmission unit 18 may transmit the frame generated by the first frame processing unit 17 to the second transmission unit 28 of the second device 20 (S60). At this time, the first transmission unit 18 and the second transmission unit 28 may be connected to a transmission line 30 such as an optical fiber to transmit and receive frames by optical communication.

6 is an exemplary view for explaining a signal reception process of the second device of the mobile communication repeater according to an embodiment of the present invention.

As illustrated in FIG. 6, the frames received by the second transmission unit 28 through the transmission line 30 may be decompressed by the second frame processing unit 27 and the decompression unit 26. .

That is, the second frame processing unit 27 distinguishes the received frame using the information included in the header, but each sample in one frame including N samples CD of the second bit stream BS2 that is compressed data. (CD) is classified (S70). At this time, the second frame processing unit 17 functions as a de-framer.

The total number of bits in one frame is M and N, while the number of bits in each sample (CD) in one frame is variable. At this time, if the total number of bits according to N samples (CD) in one frame is less than the M pieces, an additional number of bits (UB) is inserted after the last sample (CD#N). Accordingly, in this case, the second frame processing unit 27 classifies each sample CD in the bit stream excluding the additional bit UB in the second bit stream BS2.

The second decompression unit 26 decompresses the second bit stream BS2 of each sample CD to generate digital data of the third bit stream BS3 (S80). That is, the second decompression unit 26 decompresses the area occupied by the compressed bit CB in the second bit stream BS2 to convert the second bit stream BS2 to the original bit stream or the original bit stream. It can be restored as close as possible to the bit stream. In this case, the reconstructed third bit stream BS3 may include a pattern bit (PB) area, a decompression bit (UCB) area, and other bit (EB) areas.

7 is a flowchart for explaining the decompression step of FIG. 6 in more detail.

4 and 7, the second decompression unit 26 may distinguish each region in the second bit stream BS2. That is, an area occupied by the pattern bit PB, an area occupied by the compressed bit CB, and an area occupied by the residual bit'(RB') may be distinguished.

The step of assigning to the first area

Thereafter, the second decompression unit 26 may decompress the compressed data in an area occupied by the compression bit CB of the second bit stream BS2. That is, different values may be assigned to the decompression bit (UCB) region according to the size of the region occupied by the compression bit (CB).

The pattern bit (PB) area and the other bit (EB) area of the third bit stream BS3 are of the area occupied by the pattern bit PB of the second bit stream BS2 and the area occupied by the residual bit'(RB'). Each bit is allocated, and a bit in which the compressed bit CB of the region occupied by the compressed bit CB of the second bit stream BS2 is decompressed may be allocated to the decompressed bit UCB region.

Specifically, a bit that repeats the pattern bit PB by a number n corresponding to the binary number of the compression bit CB may be allocated to the decompression bit UCB area. In addition, additionally, the next bit (NB), which is a bit of a binary number different from the last bit when the compressed bit (CB) is repeated n+1, may be allocated at the beginning of the other bit (EB) area.

For example, consider a case in which the region occupied by the pattern bit PB is '10' and the region occupied by the compressed bit CB is '101' in the second bit stream BS2. In this case, the pattern bits (PB) '1' and '0' are repeated by the number 5 corresponding to the compression bit (CB) '101', so that '10101' is allocated to the decompression bit (UCB) area. Can be. In addition, when pattern bits (PB) '1' and '0' are repeated by 5+1 times, the last bit is '0', and the binary number '1' different from this '0' is the next bit (NB ) To the beginning of the guitar bit (EB) area.

Also, the guitar bit (EB) area may be allocated as follows. First, when n is smaller than the reference value (η), the remaining bits' (RB') of a predetermined number (C) of the second bit stream BS2 may be allocated to the other bits EB area. That is, when n has a value smaller than a preset threshold value η, since the length of the area occupied by the residual bit'(RB') in the second bit stream BS2 is C, the corresponding residual bit' ( RB') in the guitar bit (EB) area. Conversely, when n is greater than the reference value η, the number of residual bits'(RB') smaller than C of the second bit stream BS2 may be allocated to the other bits EB area. That is, when n has a value equal to or greater than η, it means that the length of the region occupied by the residual bit'(RB') in the second bit stream BS2 is small (for example, C-1) C is small. The corresponding number of remaining bits' (RB') can be restored to the other bits (EB) area.

On the other hand, the total number of bits in the pattern bit (PB) area, decompression bit (UCB) area, and other bit (EB) area restored to date is greater than the total number of first bit stream (BS1) bits before compression. It can be shortened or lengthened. In the case of shrinking, after filling the remaining bits of the other bit (EB) area with an arbitrary bit value or a predetermined predetermined bit pattern according to the total number of bits of the original first bit stream (BS1) before compression, the final third bit Generate heat (BS3). On the contrary, if it becomes long, only the original number of bits is restored as much as the total number of bits of the original first bit stream BS1 before compression to generate the final third bit stream BS3, and the rest are ignored.

When the above-described method is applied to a commercial optical repeater system, a compression method that is adaptive to the bit pattern length can compress at least 0.3 bits per sample more than the case where it is not, and the lower the input signal level, the more The compression rate increases.

The above-described compression and decompression method according to FIGS. 4 to 7 is only an embodiment, and the present invention varies the size of a bit length reduction value in a region occupied by the residual bit'(RB') in the bit stream BS2. It also includes setting and setting the type of the threshold value η, which is a criterion for reducing the bit length, rather than one. For example, if two threshold values are used, if n is equal to or greater than the first threshold, the bit length can be reduced by C-1, and when n is greater than or equal to the second threshold, bits The length can be reduced by C-2.

6 again, the second DA converter 23 may convert the digital data restored by the second decompressor 26 into an analog signal of the baseband (S90). At this time, the second DA converter 23 receives digital data in which I bits I0, I1, I2, ... and Q bits (Q0, Q1, Q2, ...) are separated from the second decompressor 26, and I It is possible to generate analog signals of signals and Q signals.

Thereafter, the second baseband processing unit 22 may convert the signal of the baseband to a signal of the IF band (S100). Also, the second frequency converter 21 may convert the IF band signal processed by the second base band processor 22 into an RF band signal for transmission to the user terminal 3 (S110).

Meanwhile, an uplink process, that is, a process in which signals are transmitted from the user terminal to the second device 20, from the second device 20 to the first device 10, and from the first device 10 to the base station, respectively May correspond to the aforementioned downlink process S10 to S110. Therefore, the description thereof will be omitted below.

Although the embodiments according to the present invention have been described above, they are merely exemplary, and those skilled in the art will understand that various modifications and equivalent ranges of the embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined by the following claims.

10: first device 20: second device
11, 21: frequency converter 12, 22: base band generator
13, 23: AD converter 14, 24: DA converter
15, 25: compression section 16, 26: decompression section
17, 27: frame processing unit 18, 28: transmission unit

Claims (13)

A compressing step of compressing the first bit string obtained by converting the mobile communication signal into digital data to generate compressed data of the second bit string; And
And a framing step of generating a frame including N samples of the second bit string (where N is a natural number of 2 or more),
The compression step,
And variably compressing the number of bits of the second bit stream of each sample in one frame. According to claim 1,
Data compression method characterized in that each of the N bits and the total number of bits in one frame (where M is a natural number of 2 or more) is fixed. According to claim 2,
The framing step,
When the total number of bits according to N samples in one frame is greater than the number of M, the number of second bit strings of the last sample is reduced,
And inserting an additional bit after the last sample when the total number of bits according to N samples in the one frame is less than the M samples. According to claim 1,
The compression step,
Allocating a first predetermined number of consecutive bits (pattern bits) of the first bit string to the first area of the second bit string;
Counting the number (n) of bits (pattern length bits) in which the pattern bits are repeated (where n is a natural number greater than or equal to 1) in the bit strings after the pattern bits in the first bit string; And
And allocating the second region of the second bit string as a binary number (compression bit) for the counted n. The method of claim 4,
And allocating bits (remaining bits) after the next bit of the pattern length bit in the first bit string to the third area of the second bit string according to the size of n. Way. The method of claim 5,
The step of allocating to the third area,
When the n is smaller than the reference value (η), the residual bits are set to a certain number (C) (where C is a natural number of 1 or more),
And when the reference value (η) is greater than n, setting the residual bits to a number smaller than C. A deframing step of classifying each sample in one frame including N samples of the first bit stream that is compressed data (where N is a natural number of 2 or more); And
And decompressing the first bit stream to generate digital data of the second bit stream,
The decompression step,
And decompressing a first bit stream of each sample whose bit number is variable within one frame. The method of claim 7,
The number of N bits and the total number of bits of the one frame (where M is a natural number of 2 or more) is different from each other, but is fixed.
The deframing step,
And classifying each sample in a bit stream excluding the additional bits inserted after the last sample when the total number of bits according to N samples in the one frame is less than the M samples. . The method of claim 7,
The decompression step,
Dividing the first bit sequence into regions corresponding to the first predetermined number of consecutive bits (pattern bits), regions corresponding to compressed bits, and regions corresponding to residual bits; And
And allocating the pattern bits to the first area of the second bit string, and repeating the pattern bits by a number (n) corresponding to the binary number of the compressed bits and allocating the second area of the second bit string. Data decompression method characterized in that. The method of claim 9,
Allocating a bit of a binary number different from the last bit when repeating the compressed bit by n+1 to the third area of the second bit string; And
And allocating the remaining bits to the fourth area of the second bit string. The method of claim 10,
The step of allocating to the fourth area,
When the n is smaller than the reference value η, the remaining bits of a predetermined number C (where C is a natural number of 1 or more) are allocated to the fourth region,
And when the n is greater than the reference value (η), allocating the residual bits only to a number smaller than C to the fourth region. In the mobile communication device for transmitting a mobile communication signal,
A compression unit for compressing the first bit string in which the mobile communication signal is converted into digital data to generate compressed data in the second bit string; And
And a frame processor generating a frame including N samples of the second bit string (where N is a natural number of 2 or more),
The compression unit,
A mobile communication device characterized in that the number of bits of the second bit stream of each sample is variably compressed within one frame. In the mobile communication device for transmitting a mobile communication signal,
A frame processing unit that classifies each sample in one frame including N samples of the first bit stream that is compressed data (where N is a natural number of 2 or more); And
And a decompression unit for decompressing the first bit stream to generate digital data in the second bit stream,
The decompression unit,
A method of compressing data, characterized by decompressing a first bit stream of each sample whose variable number of bits is variable within one frame.

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