KR20200025755A - Communication Apparatus, And Method Performing The Communication Apparatus - Google Patents

Abstract

Disclosed are a communication apparatus and a method performed by the communication apparatus. The method performed by the communication apparatus may comprise a signal compression method and a signal restoration method for extending a bandwidth of a digital optical link between communication apparatuses using a distributed antenna system (DAS) used in a mobile communication system. The signal compression method and the signal restoration method use a high-frequency carrier (RF)-based signal to perform the maximum compression through an up-down sampling scheme and a partial bit sampling scheme and restore the compressed signal to maintain properties of the original signal.

Description

Communication Apparatus, And Method Performing The Communication Apparatus}

The following description relates to a communication device and a method performed by the communication device, and more particularly, to a technique for providing a compression function and a recovery function of a signal to expand a bandwidth of a digital optical link in a digital distributed antenna system. It is about.

Currently, domestic and overseas telecommunications operators are focusing on whether to deliver exponentially increasing data traffic to consumers. In this regard, equipment companies need to simultaneously accommodate all frequency resources (multi-band) used in 5G and subsequent mobile communication systems as well as existing 3G / 4G mobile communication, or a number of equipments for Neutral Hosting business. It focuses on the need to simultaneously accommodate the various frequency resources used by service providers.

As a result, equipment companies are studying how to solve this problem with the biggest problem of how to efficiently use limited optical link resources. In detail, in the mobile communication repeater, in the domestic case, various frequency resources serviced by a single communication service provider are transmitted using a 6 GHz band. In addition, in the case of a foreign country, various frequency resources serviced by a plurality of communication providers are transmitted using a 10 GHz band.

At this time, the main technology used is to remove the peak to average power ratio (PAPR) value of the high output power amplifier, improve the efficiency of the amplifier, or apply linear pre-distortion (DPD) technology for the power amplifier nonlinear characteristics. Techniques to improve this have been applied.

However, the above-described techniques degrade the performance of the ADC when the device technology is used and the given bandwidth is not satisfied. Recently, in order to solve this problem, a technique of transmitting some bits except for digital data has been used, but this has a disadvantage in that it does not satisfy the reliability of the original signal during the restoration process.

The present invention can provide a signal compression method and a signal recovery method for more efficiently transmitting and receiving a high frequency carrier (RF) signal or a signal input through an optical link in a DAS distribution system.

The present invention compresses a signal in a signal compression device constituting a communication device, and restores the compressed signal in a signal recovery device constituting a communication device, thereby maintaining a property of an original signal, and allowing signal transmission and reception in a DAS distribution system. A method and a signal recovery method can be provided.

The present invention can provide a signal compression method and a signal recovery method that can improve the use efficiency of a network transmission bandwidth by applying an up-down sampling technique and a bit sampling technique to a signal.

A signal compression method performed in a communication device according to an embodiment includes sampling an analog signal input to a communication device; Converting the sampled analog signal into a digital signal comprising a sampling bit string for a sampling point of the analog signal; And compressing the digital signal by removing the lower bit string of the sampling bit string of the digital signal.

The sampling may include determining a sampling point corresponding to a position to be sampled in the analog signal based on a sampling period based on the maximum frequency of the analog signal; And sampling the analog signal using the determined sampling point of the analog signal.

Determining a sampling point according to an embodiment, the step of setting a first sampling point of the analog signal input to the communication device based on the sampling period; And setting a second sampling point of the analog signal by interpolating the analog signal having the first sampling point set to a multiple having an integer value.

In the sampling of the analog signal according to an embodiment, the first sampling point and the second sampling point of the analog signal may be sampled to have a sampling period lower than that of the analog signal.

The compressing the digital signal according to an embodiment may include: checking the number of compression bits of the sampling bit string of the digital signal; And compressing the digital signal by right shifting the sampling bit string of the digital signal according to the identified number of compressed bits.

In the compressing of the digital signal according to an embodiment, the digital signal may be compressed by removing the lower bit string of the sampling bit string by the number of compression bits through the right shift.

According to an embodiment, the digital signal may have a data amount lower than that of the analog signal input to the communication device according to the data transmission rate.

The digital signal according to an embodiment may have a compression rate determined by a sampling bit rate of a sampled analog signal and a sampling bit string from which a lower bit string according to a sampling bit string of the digital signal is removed.

According to an exemplary embodiment, a signal compression method may further include serially converting a compressed digital signal and outputting the converted digital signal through an optical link.

In one embodiment, a signal recovery method performed by a communication device includes: receiving a compressed digital signal input to the communication device; Restoring the compressed digital signal using the lower bit string of the sampling bit string of the digital signal removed in the process of compressing the digital signal; Converting the digital signal from which the sampling bit string is restored to an analog signal; And reversibly sampling the converted analog signal to restore the analog signal.

Reconstructing the compressed digital signal according to an embodiment of the present invention comprises: checking the number of compressed bits for the sampling bit string of the compressed digital signal; And left-shifting the sampling bit stream of the digital signal corresponding to the identified number of compressed bits to restore the compressed digital signal.

In one embodiment, the reconstructing of the compressed digital signal may include inserting '0' or '1' into the lower bit string of the sampling bit string removed in the process of compressing the digital signal through the left shift. Can be restored

Restoring an analog signal according to an embodiment may include setting a first sampling point of the analog signal based on a sampling period of the converted analog signal; Setting a second sampling point of the analog signal by interpolating a multiple having an integer value with respect to the analog signal to which the first sampling point is set; And sampling the first sampling point and the second sampling point of the analog signal to have a sampling period higher than that of the converted analog signal.

In a signal compression device constituting a communication device according to an embodiment, the processor comprises a processor, wherein the processor samples an analog signal input to the communication device, and the sampled analog signal is a sampling bit string for a sampling point of the analog signal. The digital signal may be compressed by converting the digital signal into a digital signal, and removing the lower bit string of the sampling bit string of the digital signal.

The processor may determine a sampling point corresponding to a position to be sampled in the analog signal based on a sampling period based on the maximum frequency of the analog signal, and sample the analog signal using the determined sampling point of the analog signal. Can be.

According to an embodiment, the processor may determine the number of compression bits of the sampling bit stream of the digital signal, and right-shift the sampling bit stream of the digital signal according to the identified number of compression bits to compress the digital signal.

The digital signal according to an embodiment may have a signal compression ratio determined by a sampling compression ratio of a sampled analog signal and a sampling bit string from which a lower bit string according to a sampling bit string of the digital signal is removed.

In the signal recovery apparatus constituting the communication device according to an embodiment, comprising a processor, the processor receives a compressed digital signal input to the communication device, sampling the digital signal removed in the process of the digital signal is compressed The lower bit string of the bit string may be used to restore the compressed digital signal, convert the digital signal from which the sampling bit string is restored to an analog signal, and reversely sample the converted analog signal to restore the analog signal.

According to an embodiment, the processor may determine the number of compression bits of the sampling bit stream of the compressed digital signal, and left-shift the sampling bit string of the digital signal to correspond to the confirmed number of compression bits. Can be restored.

According to an embodiment of the present disclosure, a processor sets a first sampling point of an analog signal based on a sampling period of the converted analog signal, and interpolates the analog signal to a multiple having an integer value with respect to the analog signal to which the first sampling point is set. Two sampling points may be set, and the first sampling point and the second sampling point of the analog signal may be sampled to have a sampling period higher than that of the converted analog signal.

The present invention can more efficiently transmit and receive a high frequency carrier (RF) signal or a signal input through an optical link in the DAS distribution system.

The present invention enables the transmission and reception of signals having an ultra-high frequency band while maintaining the current LTE-based optical transceiver for commercialization of 5G mobile communication technology, thereby significantly reducing the capex.

The present invention maximizes the effect of digital sampling bit compression by applying a sampling technique that considers digital quantization values according to quadrature amplitude modulation (QAM) used in digital optical links and mobile communication systems, and maximizes the effect of digital sampling bit compression. It can improve the use efficiency.

According to the present invention, by using an up-down sampling technique and a partial bit sampling technique using a high frequency carrier (RF) -based signal, it is possible to perform the maximum compression and restore the compressed digital signal to maintain the original signal.

1 is a diagram showing a configuration for transmitting and receiving signals between communication devices connected by a digital optical link according to an embodiment of the present invention.
2 is a diagram illustrating a communication device for compressing and restoring a signal according to an embodiment of the present invention.
3 is a view for explaining the operation of the signal compression device constituting the communication device according to an embodiment of the present invention.
4 is a diagram illustrating a process of sampling an analog signal and a process of compressing a digital signal through partial bit sampling according to an embodiment of the present invention.
5 is a view for explaining the operation of the signal recovery apparatus constituting the communication device according to an embodiment of the present invention.
6 is a diagram illustrating a process of recovering a digital signal through partial bit sampling according to an embodiment of the present invention.
7 is a flowchart illustrating a signal compression method according to an embodiment of the present invention.
8 is a flowchart illustrating a signal recovery method according to an embodiment of the present invention.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. However, various changes may be made to the embodiments so that the scope of the patent application is not limited or limited by these embodiments. It is to be understood that all changes, equivalents, and substitutes for the embodiments are included in the scope of rights.

The terminology used herein is for the purpose of description and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

In addition, in the description with reference to the accompanying drawings, the same components will be given the same reference numerals regardless of the reference numerals and duplicate description thereof will be omitted. In the following description of the embodiment, if it is determined that the detailed description of the related known technology may unnecessarily obscure the gist of the embodiment, the detailed description thereof will be omitted.

1 is a diagram showing a configuration for transmitting and receiving signals between communication devices connected by a digital optical link according to an embodiment of the present invention.

Referring to FIG. 1, a communication device is a device for transmitting and receiving a signal, and may be a device for processing a signal transmitted and received by a mobile communication base station or a distributed antenna system (DAS). The communication device in the present invention may be divided into a communication device 101 for transmitting a signal and a communication device 108 for receiving a signal. In one example, the communication device 101 may be a DAS Distribution Unit (DAS Distribution Unit, Host Unit or Head End Unit). In addition, the communication device 108 may be a remote unit. In addition, the communication devices 101 and 108 may be connected to each other through a digital optical link.

The communication device 101 corresponding to the transmission device may include an RF antenna connector 104, a decoding / deframer 105, a signal compression device 102, a signal recovery device 103, and a signal converter 107. have.

The RF antenna connector 104 may detect an RF signal used for mobile communication frequency transmission. In addition, the RF antenna connector 104 may receive a digital baseband based analog signal according to the RF signal.

The decoding / deframer 105 may receive an analog signal having a wireless interface standard output from an input device 106 such as a base station or a small cell through a digital optical link.

The signal compression device 102 may be a device that performs maximum compression on a digital signal using an up-down sampling and bit sampling technique on an analog signal. In addition, the signal recovery apparatus 103 may be a device for maintaining the nature of the original signal by recovering the compressed digital signal.

The signal converter 107 may convert the signal in order to use a digital optical link.

The communication device 108 corresponding to the reception device may include a signal converter 111, a signal compression device 109, a signal recovery device 110, and an RF antenna connector 112. Operation of each component may perform the same operation as that of each component of the communication apparatus 101 corresponding to the transmitting apparatus.

In the present invention, the optical link compression transmission apparatus employs an up-down sampling method and a data bit compression and recovery method when converting an analog signal transmitted / received from a mobile communication base station or a distributed antenna system into a digital baseband digital signal. Can be applied. Through this, the present invention can have an application range capable of a compression rate of up to 50% while minimizing a delay occurring in the process of transmitting and receiving a signal.

Also, when the signal is recovered after compression, an additional error vector magnitude (EVM) may be generated compared to the original signal before compression. At this time, since the mobile communication equipment allows a certain level of EVM (for example, up to 8% of the EVM in the 64QAM / 20MHz band), if the signal after restoration is within the allowable value, it can be regarded as the same signal as the original signal. Accordingly, the present invention can reduce the infrastructure investment cost of 5G and subsequent mobile communication systems by using the existing optical link infrastructure as it is in a mobile communication system using a digital optical link.

In addition, according to the present invention, as the signal compression method and the signal recovery method in the communication device can be performed, an additional delay time may satisfy a low delay characteristic of several μsec.

2 is a diagram illustrating a communication device for compressing and restoring a signal according to an embodiment of the present invention.

Referring to FIG. 2, the communication device may be a DAS distribution device 201 and a remote device 207 from a device used in a digital distribution system. The DAS distribution device 201 may be a communication device corresponding to a transmitting device, and the remote device 207 may be a communication device corresponding to a receiving device. The DAS distribution device 201 and the remote device 207 may be connected to each other through a digital optical link. In this case, the DAS distribution device 201 and the remote device 207 may have the same symmetrical structure.

The input signals 205 and 211 may be analog signals having a wireless interface standard received from a base station or a small cell, or may be baseband-based analog signals converted from RF signals in air transmitted from a base station. For example, in the case of an RF-based signal, when the RF signal for LTE 20MHz is received, a signal converted to 46.08MHz / 12-bit signal after baseband conversion may be an output.

The signal compression devices 202 and 208 may be devices for compressing the input signals 205 and 211 received by the communication device. In detail, the signal compression devices 202 and 208 may sample an analog signal input to the communication device and convert the sampled analog signal into a digital signal including a sampling bit string regarding a sampling point of the analog signal. have. Thereafter, the signal compression devices 202 and 208 can compress the digital signal by removing the lower bit string of the sampling bit string constituting the converted digital signal. More details will be described with reference to FIGS. 3 and 4.

The signal recovery apparatus 203, 209 may be a device for reconstructing the compressed digital signal received through the digital optical link to reproduce the characteristics of the original signal. In detail, the signal recovery apparatuses 203 and 209 receive the compressed digital signal input to the communication apparatus, and are compressed using the lower bit string of the sampling bit string of the digital signal removed in the process of compressing the digital signal. The digital signal can be restored. The signal reconstruction apparatuses 203 and 209 may reconstruct the analog signal by converting the digital signal from which the sampling bit string is restored into an analog signal and then sampling the converted analog signal in reverse. More details will be described with reference to FIGS. 5 and 6.

The output signals 206 and 212 are wireless interface standard signals received from a base station or a small cell, or error vector values are lost during compression and restoration in preparation for RF signals in the air transmitted from the base station. Loss) may be an additional signal. At this time, the output signal can be regarded as the first input signal if the error vector value is within the allowable range.

The DAS distribution device 201 and the remote device 207, which are communication devices, are connected to each other through a digital optical link, and the DAS distribution device 201 and the remote device 207 are signal converters at both ends, respectively, in order to use the digital optical link. 204, 210. In one example, signal converters 204 and 210 may be optical transceivers.

Here, the signal converters 204 and 210 may perform parallel to serial operations in response to the outputs of the signal compression devices 202 and 208. In addition, the optical transceivers 204 and 210 may perform serial to parallel operations in response to the inputs of the signal recovery apparatuses 203 and 209.

3 is a view for explaining the operation of the signal compression device constituting the communication device according to an embodiment of the present invention.

Referring to FIG. 3, the signal compression device 301 may include a processor 302. In addition, the processor 302 may generate an compressed digital signal 304 by compressing the analog signal 303 corresponding to the original signal.

The signal compression device 301 may compress the analog signal 303 into the digital signal 304 by using an up-down sampling technique. The signal compression device 301 may receive the analog signal 303 input to the communication device. Here, the analog signal 303 may be an analog signal having a radio interface standard received from a base station or a small cell. In addition, the analog signal may be a baseband-based analog signal converted from the RF signal transmitted from the base station.

The signal compression device 301 may sample the analog signal 303 input to the communication device. The signal compression device 301 may upsample the analog signal 303 through an interpolation technique. In detail, the signal compression device 301 may determine a sampling point corresponding to a position to be sampled in the analog signal based on a sampling period based on the maximum frequency of the analog signal. At this time, the signal compression device 301 may set the first sampling point of the analog signal input to the communication device based on the sampling period. The signal compression device 301 may perform upsampling by setting a second sampling point of the analog signal by interpolating the analog signal having the first sampling point set to a multiple having an integer value.

For example, the signal compression device 301 may perform an upsampling process for increasing the sampling point of the analog signal 303 by two or three times using the interpolation technique with respect to the analog signal 303.

Thereafter, the signal compression device 301 may sample the analog signal 303 using the determined sampling point of the analog signal 303. In detail, the signal compression device 301 may down-sample by sampling the first sampling point and the second sampling point of the analog signal 303 to have a sampling period lower than that of the analog signal 303.

As an example, the signal compression device 301 may perform a sampling process for transmitting only 2/3 or 3/4 of the analog signals less than the received analog signal 303 using the decimation technique.

The signal compression device 301 may generate a sampling bit string through an analog-to-digital converter (ADC) process for a sampling point of a digital baseband-based analog signal. Here, the sampling bit string may be a block capable of processing m bits for the sampling point of the analog signal.

The signal compression device 301 may compress the digital signal by removing the lower bit string of the sampling bit string constituting the converted digital signal. In detail, the signal compression device 301 may compress the digital signal using a partial bit sampling technique. Here, the partial bit sampling technique may be a technique of removing the lower n bits with respect to the sampling bit string of the digital signal input as m bits when performing the compression process. In addition, the partial bit sampling technique may be a technique of restoring the removed lower n bits when performing the restoration process.

Through this process, the compressed digital signal 304 may have a data amount lower than that of the analog signal input to the communication device according to the data transmission rate.

In addition, the compression ratio of the compressed digital signal 304 may be determined by the sampling compression ratio of the sampled analog signal and the sampling bit string from which the lower bit string according to the sampling bit string of the digital signal is removed. In detail, the compression rate of the compressed digital signal 304 may be expressed by Equation 1 below.

For example, the signal compression device 301 may apply Equation 1 to an RF signal-based digital repeater. Accordingly, assuming that the sampling compression ratio of the sampled analog signal is 3/4, and the sampling bit string of the digital signal transmits only 8 bit strings out of a total of 12 bit strings, the total compression ratio of the digital signal is 50%. This may mean that the compression restoration process is possible with only half of the total data. This can be expressed as Equation 2 of the wife.

As a result, the signal compression device 301 can maximize the effect of digital sampling bit compression and improve the efficiency of network transmission bandwidth by applying the up-down sampling technique and the partial bit sampling technique in digital optical link and mobile communication systems. have.

4 is a diagram illustrating a process of sampling an analog signal and a process of compressing a digital signal through partial bit sampling according to an embodiment of the present invention.

Referring to FIG. 4, the signal compression apparatus may perform maximum compression on a digital signal using an up-down sampling technique and a bit sampling technique. For example, when a 46.08 MHz baseband analog signal needs to be transmitted through a digital optical link, the signal compression device may be capable of downsampling to 30.72 MHz according to an up-down sampling method and a bit sampling method.

In more detail, the signal compression device may sample an analog signal input to the communication device. The signal compression apparatus may determine a sampling point corresponding to a position to be sampled in the analog signal based on a sampling period based on the maximum frequency of the analog signal. The signal compression device may sample the analog signal using the determined sampling point of the analog signal. Here, the signal compression device may perform sampling in three steps as shown in FIG.

① Phase 1

The signal compression device may set a first sampling point of the analog signal input to the communication device based on the sampling period. That is, the signal compression apparatus may set the first sampling point of the analog signal according to the sampling period for sampling the analog signal corresponding to the original signal.

② Phase 2

The signal compression device may set the second sampling point of the analog signal by interpolating the analog signal having the first sampling point set to a multiple having an integer value. In other words, the signal compression apparatus may add sampling points in the analog signal based on interpolation. This may be the same as performing upsampling for the sampling point. The signal compression device can express the analog signal in more detail by increasing the sampling point in the analog signal. The signal compression device may add n sampling points as a second sampling point of the analog signal.

For example, the signal compression apparatus may set the second sampling point of the analog signal by interpolating twice or three times with respect to the analog signal in which the first sampling point is set.

③ Phase 3

The signal compression device may sample the first sampling point and the second sampling point of the analog signal. The signal compression device may perform sampling to have a sampling period lower than that of the analog signal. Here, the signal compression device may sample the analog signal in consideration of the sampling bit string m regarding the sampling point of the analog signal and the time according to the added sampling point n. This may be the same as performing down sampling for the sampling point.

Through this process, the signal compression device may perform up-down sampling on the analog signal input to the communication device.

Referring to FIG. 4B, the signal compression apparatus may compress the digital signal by removing the lower bit string of the sampling bit string constituting the converted digital signal. In detail, the signal compression apparatus may convert the sampled analog signal into a digital signal including a sampling bit string for a sampling point of the analog signal. Here, the converted digital signal may be configured as a block that can process m bits for the sampling point.

The signal compression apparatus may delete the lower bit string m for the sampling bit string of the converted digital signal by applying the partial bit sampling technique. In this case, the erasable lower bit string m may be a data unit that does not degrade the original signal in the process of restoring the signal. For example, the lower bit string m may be about 12 bits when applied to an RF-based digital optical repeater.

The signal compression device can compress the digital signal by removing the lower bit string of the sampling bit string.

5 is a view for explaining the operation of the signal recovery apparatus constituting the communication device according to an embodiment of the present invention.

Referring to FIG. 5, the signal recovery apparatus 501 may include a processor 502. The processor 502 may restore the compressed digital signal 503 input through the digital optical link to the analog signal 504 corresponding to the original signal. In this case, the processor 502 may go through a process of restoring the compressed digital signal 503 in the reverse order of the compression process performed by the signal compression apparatus. That is, the signal recovery method performed by the signal recovery apparatus 501 may proceed in the reverse process of the technique used in the signal compression method.

The signal recovery device 501 may receive the compressed digital signal 503 input to the communication device. Here, the signal recovery device 501 may receive data transmitted through a digital optical link connected to the communication device as an input signal. The input signal may be a digital signal 503 compressed by a signal compression device.

The signal recovery apparatus 501 may perform synchronization on the compressed digital signal 503. In detail, the compressed digital signal 503 may vary in size due to noise or distortion occurring on the transmission channel in the course of being transmitted through the digital optical link. Accordingly, the signal recovery apparatus 501 may process the synchronized compressed digital signal 503 after synchronizing the compressed digital signal 503 whose size may change.

The signal recovery apparatus 501 may restore the compressed digital signal using the lower bit string of the sampling bit string of the digital signal removed in the process of compressing the digital signal. The signal recovery apparatus 501 may perform a restoration process applying the partial bit sampling technique. The signal recovery apparatus 501 may restore the compressed digital signal by inserting '0' or '1' into the lower bit string of the sampling bit string removed in the process of compressing the digital signal. This may be to minimize data corruption caused by the lower bit string removed during the compression process when restoring the analog signal corresponding to the original signal.

To this end, the signal recovery apparatus 501 may insert arbitrary '0' and '1' into the lower bit string to be restored.

The signal recovery apparatus 501 may convert the digital signal from which the sampling bit string is restored into an analog signal. The signal recovery apparatus 501 may convert a digital signal restored through signal conversion into a baseband based analog signal.

The signal recovery apparatus 501 may restore the analog signal by reversely sampling the converted analog signal. The signal recovery apparatus 501 may restore the analog signal by applying the order of progress of the up-down sampling technique used in the signal compression method in the reverse order.

In detail, the signal recovery apparatus 501 may set the first sampling point of the analog signal based on the sampling period of the converted analog signal. The signal recovery apparatus 501 may set the second sampling point of the analog signal by interpolating the analog signal having the first sampling point set to a multiple having an integer value. The signal recovery apparatus 501 may restore the analog signal corresponding to the original signal by sampling the first sampling point and the second sampling point of the analog signal to have a sampling period higher than that of the converted analog signal.

6 is a diagram for describing a process of recovering a digital signal through partial bit sampling according to an embodiment of the present invention.

Referring to FIG. 6, the signal recovery apparatus may restore the compressed digital signal input to the communication device. The signal recovery apparatus may restore the compressed digital signal by using the lower bit string of the sampling bit string of the digital signal removed in the process of compressing the digital signal.

To this end, the signal recovery apparatus may check the number of compression bits for the sampling bit string of the compressed digital signal. Here, the number of compression bits may correspond to the number of right-shifted lower bit strings for compressing the digital signal in the signal compression device constituting the communication device. That is, as shown in FIG. 6, in the compressed digital signal, “b3, b2, b1, b0” corresponding to the lower bit string may be removed from the digital signal to which the ADC is applied through the right shift.

The signal recovery apparatus may restore the compressed digital signal by performing a left shift on the sampling bit string of the digital signal corresponding to the identified number of compressed bits. In this case, the signal recovery apparatus may restore the compressed digital signal by inserting '0' or '1' into the lower bit string of the sampling bit string removed in the process of compressing the digital signal through the left shift.

In addition, the signal recovery apparatus may restore the digital signal using a Gaussian distribution. In other words, the signal recovery apparatus inserts half of the lower bit string as '1' and inserts the remaining lower bit string as '0' in consideration of the Gaussian distribution of the lower bit string of the sampling bit string removed in the process of compressing the digital signal. can do.

7 is a flowchart illustrating a signal compression method according to an embodiment of the present invention.

In operation 701, the signal compression device configuring the communication device may sample an analog signal input to the communication device. Here, the analog signal may be an analog signal having a radio interface standard received from a base station or a small cell. In addition, the analog signal may be a baseband-based analog signal converted from the RF signal transmitted from the base station.

The signal compression device can apply an up-down sampling technique to the analog signal to sample the analog signal. In detail, the signal compression apparatus may determine a sampling point corresponding to a position to be sampled in the analog signal based on a sampling period based on the maximum frequency of the analog signal. In this case, the signal compression apparatus may determine a sampling point through up-sampling among up-down sampling techniques. In other words, the signal compression device may set the first sampling point of the analog signal input to the communication device based on the sampling period. The signal compression device may set the second sampling point of the analog signal by interpolating the analog signal having the first sampling point set to a multiple having an integer value.

Thereafter, the signal compression device may sample the analog signal using the sampling point of the analog signal. In this case, the signal compression apparatus may determine a sampling point through down-sampling among up-down sampling techniques. The signal compression device may sample the first sampling point and the second sampling point of the analog signal to have a sampling period lower than that of the analog signal.

In operation 702, the signal compression device configuring the communication device may convert the sampled analog signal into a digital signal including a sampling bit string for a sampling point of the analog signal. The signal compression device may use a signal conversion technique (ADC) that converts an analog signal into a digital signal. The signal compression device may convert an analog signal into a digital signal to include a sampling bit string consisting of blocks that process m-bit sampling for a sampling point.

In operation 703, the signal compression apparatus configuring the communication device may compress the digital signal by removing the lower bit string of the sampling bit string constituting the converted digital signal. In detail, the signal compression apparatus may check the number of compression bits for the sampling bit string of the digital signal. The signal compression apparatus may compress the digital signal by right shifting the sampling bit string of the digital signal according to the identified number of compression bits. The signal compression apparatus may compress the digital signal by removing the lower bit string of the sampling bit string by the number of compression bits through the right shift. In this case, the digital signal may have a data amount lower than the data amount of the analog signal input to the communication device according to the data transmission rate. In addition, the compression ratio of the digital signal may be determined by the sampling compression ratio of the sampled analog signal and the sampling bit string from which the lower bit string according to the sampling bit string of the digital signal is removed.

The signal compression device may increase the use efficiency of network transmission bandwidth in a mobile communication system by compressing a signal in a process of converting an analog signal into a digital signal.

8 is a flowchart illustrating a signal recovery method according to an embodiment of the present invention.

In operation 801, the signal recovery apparatus configuring the communication device may receive a compressed digital signal input to the communication device. The signal recovery apparatus may receive a compressed digital signal output from a communication device connected by a digital optical link.

In operation 802, the signal recovery apparatus configuring the communication device may restore the compressed digital signal using the lower bit string of the sampling bit string of the digital signal removed in the process of compressing the digital signal. In detail, the signal recovery apparatus may check the number of compression bits for the sampling bit string of the compressed digital signal. The signal recovery apparatus may restore the compressed digital signal by left shifting the sampling bit string of the digital signal corresponding to the identified number of compressed bits.

In this case, the signal recovery apparatus may restore the compressed digital signal by inserting '0' or '1' into the lower bit string of the sampling bit string removed in the process of compressing the digital signal through the left shift.

In operation 803, the signal recovery apparatus configuring the communication device may convert the digital signal from which the sampling bit string is restored into an analog signal. The signal recovery apparatus may use a signal conversion technique (CDA) in which the signal compression apparatus converts a digital signal into an analog signal.

In operation 804, the signal recovery apparatus configuring the communication device may reversely sample the converted analog signal to restore the analog signal. The signal recovery apparatus may set the first sampling point of the analog signal based on the sampling period of the converted analog signal. The signal reconstruction apparatus may set the second sampling point of the analog signal by interpolating a multiple having an integer value with respect to the analog signal to which the first sampling point is set.

The signal recovery apparatus may restore the analog signal by sampling the first sampling point and the second sampling point of the analog signal to have a sampling period higher than that of the converted analog signal.

The signal recovery apparatus recovers the compressed digital signal input through the digital optical link to the analog signal by performing a reverse sampling process, thereby maintaining the original signal properties of the analog signal in the mobile communication system.

The method according to the embodiment may be embodied in the form of program instructions that can be executed by various computer means and recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the media may be those specially designed and constructed for the purposes of the embodiments, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer readable recording media include magnetic media such as hard disks, floppy disks and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

The software may include a computer program, code, instructions, or a combination of one or more of the above, and may configure the processing device to operate as desired, or process independently or collectively. You can command the device. Software and / or data may be any type of machine, component, physical device, virtual equipment, computer storage medium or device in order to be interpreted by or to provide instructions or data to the processing device. Or may be embodied permanently or temporarily in a signal wave to be transmitted. The software may be distributed over networked computer systems so that they may be stored or executed in a distributed manner. Software and data may be stored on one or more computer readable recording media.

Although the embodiments have been described with reference to the accompanying drawings, those skilled in the art may apply various technical modifications and variations based on the above. For example, the described techniques may be performed in a different order than the described method, and / or components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different form than the described method, or other components. Or even by substitution or replacement by equivalents, an appropriate result can be achieved.

Therefore, other implementations, other embodiments, and equivalents to the claims are within the scope of the following claims.

101: communication device (DAS) 102: signal compression device
103: signal recovery device 104: RF antenna connector
105: decoding / deframer 106: base station-small cell
107: signal converter (E / O)
108: communication unit 109: signal compression device
110: signal recovery device 111: signal converter (O / E)
112: RF antenna adapter

Claims (20)

In the signal compression method performed in a communication device,
Sampling an analog signal input to the communication device;
Converting the sampled analog signal into a digital signal comprising a sampling bit string for a sampling point of the analog signal; And
Compressing the digital signal by removing the lower bit string of the sampling bit string constituting the converted digital signal
Signal compression method comprising a. The method of claim 1,
The sampling step,
Determining a sampling point corresponding to a position to be sampled in the analog signal based on a sampling period based on the maximum frequency of the analog signal; And
Sampling the analog signal using the determined sampling point of the analog signal
Signal compression method comprising a. The method of claim 2,
Determining the sampling point,
Setting a first sampling point of an analog signal input to a communication device based on the sampling period; And
Setting a second sampling point of the analog signal by interpolating a multiple having an integer value with respect to the analog signal to which the first sampling point is set;
Signal compression method comprising a. The method of claim 3,
Sampling the analog signal,
And a first sampling point and a second sampling point of the analog signal so as to have a sampling period lower than that of the analog signal. The method of claim 1,
Compressing the digital signal,
Checking the number of compression bits for the sampling bit stream of the digital signal; And
Compressing the digital signal by right shifting the sampling bit stream of the digital signal according to the identified number of compressed bits;
Signal compression method comprising a. The method of claim 5,
Compressing the digital signal,
And compressing the digital signal by removing the lower bit string of the sampling bit string by the number of compression bits through the right shift. The method of claim 1,
The digital signal,
A signal compression method having a data amount lower than that of an analog signal input to a communication device according to a data transmission rate. The method of claim 1,
The digital signal,
And a compression ratio determined by a sampling bit rate of the sampled analog signal and a lower bit string corresponding to a sampling bit string of the digital signal. The method of claim 1,
Outputting the compressed digital signal through an optical link by serially converting the digital signal;
Signal compression method further comprising. In the signal recovery method performed in the communication device,
Receiving a compressed digital signal input to the communication device;
Restoring the compressed digital signal using the lower bit string of the sampling bit string of the digital signal removed in the process of compressing the digital signal;
Converting the digital signal from which the sampling bit string is restored to an analog signal; And
Restoring the analog signal by inversely sampling the converted analog signal
Signal recovery method comprising a. The method of claim 10,
Restoring the compressed digital signal,
Checking the number of compression bits in the sampling bit string of the compressed digital signal; And
Restoring the compressed digital signal by left shifting the sampling bit string of the digital signal corresponding to the identified number of compressed bits
Signal recovery method comprising a. The method of claim 12,
Restoring the compressed digital signal,
And reconstructing the compressed digital signal by inserting '0' or '1' into a lower bit string of the sampling bit string removed in the process of compressing the digital signal through the left shift. The method of claim 10,
Restoring the analog signal,
Setting a first sampling point of the analog signal based on a sampling period of the converted analog signal;
Setting a second sampling point of the analog signal by interpolating a multiple having an integer value with respect to the analog signal having the first sampling point set; And
Sampling a first sampling point and a second sampling point of the analog signal to have a sampling period higher than a sampling period of the converted analog signal
Signal recovery method comprising a. In the signal compression device constituting the communication device,
Includes a processor,
The processor,
Sampling an analog signal input to the communication device,
Converting the sampled analog signal into a digital signal comprising a sampling bit string for a sampling point of the analog signal,
And a signal compression device compressing the digital signal by removing the lower bit string of the sampling bit string of the digital signal. The method of claim 14,
The processor,
And a sampling point corresponding to a position to be sampled in the analog signal based on a sampling period based on the maximum frequency of the analog signal, and sampling the analog signal using the determined sampling point of the analog signal. The method of claim 14,
The processor,
And compressing the digital signal by checking the number of compression bits of the sampling bit string of the digital signal and right shifting the sampling bit string of the digital signal according to the identified number of compression bits. The method of claim 14,
The digital signal,
And a compression rate determined by a sampling bit rate of the sampled analog signal and a lower bit string corresponding to the sampling bit string of the digital signal. In the signal recovery apparatus constituting the communication device,
Includes a processor,
The processor,
Receive a compressed digital signal input to the communication device,
Reconstructing the compressed digital signal using the lower bit string of the sampling bit string of the digital signal removed in the process of compressing the digital signal,
Converting the digital signal from which the sampling bit string is restored to an analog signal,
And restoring the analog signal by inversely sampling the converted analog signal. The method of claim 18,
The processor,
Restoring the compressed digital signal by checking the number of compression bits for the sampling bit string of the compressed digital signal and left shifting the sampling bit string of the digital signal corresponding to the identified number of compressed bits Way. The method of claim 18,
The processor,
Setting a first sampling point of the analog signal based on a sampling period of the converted analog signal,
The second sampling point of the analog signal is set by interpolating the analog signal to which the first sampling point is set by a multiple having an integer value.
And a first sampling point and a second sampling point of the analog signal to have a sampling period higher than a sampling period of the converted analog signal.

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