KR20180135427A - Signal transmitting apparatus and signal transmitting method - Google Patents

Abstract

The present invention discloses a signal transmitting apparatus and a signal transmitting method, capable of improving system performance and solving all problems caused by radiation noise by removing the noise radiated through an antenna during a switching section in which at least one of a beam pattern and a gain of a beam is switched in an analog beamforming communication system.

Description

Technical Field [0001] The present invention relates to a signal transmission apparatus and a signal transmission method,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to beam pattern and gain switching in a beamforming technique, and more particularly, to a method and apparatus for switching an antenna during a switching period in which at least one of a beam pattern and a gain of a beam is switched in a communication system employing an analog- To a technique for eliminating noise radiated through the antenna.

In the next-generation ultra high-speed and low-delay communication system, that is, the 5G system, a very high frequency band is used to accommodate increasing mobile traffic. Since the ultra-high frequency band has a large path loss, beamforming technology is essentially adopted.

Assuming that the number of antennas of the transmitting apparatus and the number of antennas of the receiving apparatus are provided, the beam forming technique forms a beam (beam-formed) focused in a specific direction through each antenna of the transmitting apparatus and the receiving apparatus This is a technique for transmitting and receiving signals.

Particularly, a communication system employing an analog beamforming technique for forming a beamformed beam in an analog manner sets the beam pattern and the gain of the beam to be switchable on a symbol-by-symbol basis.

Thus, in a communication system employing analog beamforming, the beam pattern of the beam and the gain switching (RF conversion) can occur very frequently.

In the analog beamforming communication system, an unstable signal that can not be predicted is transmitted through the antenna during a physical time (hereinafter, referred to as a switching period) required until the beam pattern or gain switching of the beam is completed and completed, Can be considered.

Thus, in the analog beamforming communication system, noise of a very strong intensity is radiated due to a noise signal transmitted through an antenna during a switching period in which at least one of a beam pattern and a gain of a beam is switched, Causing noise in the frequency band of other companies, deteriorating the terminal synchronization performance, causing noise to the adjacent base station in a multi-cell environment, and the like.

However, in the conventional analog beam forming communication system, a method for eliminating noise radiated through an antenna during a switching period in which at least one of a beam pattern and a gain of a beam is switched is not proposed.

Accordingly, the present invention proposes a concrete scheme for eliminating noise radiated through an antenna during a switching period in which at least one of a beam pattern and a gain of a beam is switched in an analog beamforming communication system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object to be achieved by the present invention is to provide an analog beamforming communication system in which, during a switching period in which at least one of a beam pattern and a gain of a beam is switched, In order to eliminate the above-mentioned problems.

According to a first aspect of the present invention, there is provided a signal transmission apparatus for transmitting a signal through a beamformed beam, comprising: an RF circuit unit for switching a beam pattern and a gain of the beam; And a noise eliminator for transmitting a specific signal through the antenna during a switching period in which at least one of the beam pattern and the gain of the beam is switched.

Preferably, the noise eliminator outputs a transmission signal to the RF circuit unit so that the transmission signal is transmitted through the antenna in the RF circuit unit, and after the position of the switching period and the transmission signal are output, And a specific signal is output to the RF circuit unit in place of the transmission signal during the switching section matching time calculated based on the transmission delay time until transmission is performed through the RF circuit unit.

Preferably, the noise eliminator is a RF signal transmitter for transmitting a transmission signal input to the RF circuit through the antenna, and for transmitting a specific signal instead of the transmission signal, .

Preferably, the switching section is configured to switch, among the plurality of symbols in a subframe used for data transmission, a specific symbol requiring switching of at least one of a beam pattern and a gain with respect to a previous symbol based on predefined symbol unit RF information (CP) interval defined in the CP interval, or a separate interval that is excluded from the CP interval.

Preferably, the CP interval of the specific symbol is variable among the plurality of samples preliminarily utilized for the CP interval in the symbol, to the remaining samples except for the sample from the most previous sample to the sample in which the switch interval is received .

Preferably, the baseband processor outputs an RF control signal according to the RF information of the specific symbol to the RF circuit unit when the specific symbol is recognized, and the RF circuit unit adjusts the beam pattern of the beam according to the RF control signal, And an RF control unit for outputting the RF control signal at an output time calculated based on a time required for switching at least one of the gain and the gain until the RF control signal is outputted and then inputted to the RF circuit unit .

Preferably, the baseband processor recognizes the position of the switching section based on the output time at which the RF control signal is output when the specific symbol is recognized, the time required for the switching, the time of the switching section, And a transmission signal output unit for outputting the specific signal to the RF circuit unit instead of the transmission signal during a switching section matching time calculated based on the position and the transmission delay time.

Preferably, the specific signal is an O-level digital signal.

According to a second aspect of the present invention, there is provided a signal transmission method of a device for transmitting a signal through a beamformed beam, the method comprising the steps of: A recognition step of recognizing the position; Calculating a switching interval matching time based on a position of the switching section and a transmission delay time until transmission signals output from the baseband processing section are transmitted through the antenna; And a noise removing step of outputting a specific signal during the switching section matching time in the baseband processing section and transmitting the specific signal through the antenna during the switching section.

Thus, according to the signal transmission apparatus and the signal transmission method of the present invention, in the analog beam-forming communication system, by removing the noise radiated through the antenna during the switching period in which at least one of the beam pattern and the gain of the beam is switched, It is possible to solve all the problems caused and improve the system performance.

1 is an exemplary diagram showing a communication system employing a beam forming technique to which the present invention is applied.
2 is a hardware block diagram illustrating a configuration of a signal transmission apparatus according to a preferred embodiment of the present invention.
3 is an exemplary diagram showing an existing situation in which noise is radiated during a switching period.
FIGS. 4 and 5 are exemplary diagrams illustrating a situation in which noises radiated during a switching period are eliminated by the present invention. FIG.
FIG. 6 and FIG. 7 illustrate examples of a case where an OFDM modulation scheme is used in an analog beamforming communication system to which the present invention is applied, and a beam pattern and a gain switching (RF conversion) are performed in a CP region.
8 is a flowchart illustrating a signal transmission method according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is an exemplary diagram showing a communication system employing a beam forming technique to which the present invention is applied.

Assuming that the number of antennas of the transmitting apparatus and the number of antennas of the receiving apparatus are provided, the beam forming technique forms a beam (beam-formed) focused in a specific direction through each antenna of the transmitting apparatus and the receiving apparatus And transmits and receives signals through this beam.

1, the base station 100 and the terminal 10 constituting the communication system adopting the beam forming technique each include a plurality of antennas to form a beam-formed beam.

The direction (e.g., beam # 1, # 2, ... # 8) and gain (e.g., gain # 1, # 2, ..., #n) of the base station 100 can form various beams, (E.g., beams 1, 2, ... 4) and gain (e.g., gain # 1, #, 2, ..., #n) in the case of the terminal 10 can form various beams.

In the next generation ultra high-speed and low-delay communication system, that is, the 5G system, the ultra high frequency band is used to accommodate the increasing mobile traffic. However, since the ultra high frequency band has a large path attenuation, the above-described beam forming technique is essentially adopted.

Meanwhile, a communication system employing an analog beamforming technique for forming a beamformed beam in an analog manner sets a beam pattern and a gain of a beam to be able to be switched on a symbol-by-symbol basis.

For example, in the case of downlink, the BS 100 switches synchronization signals required for transmission to all terminals in the network and beam direction for each symbol in a broadcast channel.

In the case of the uplink, the terminal 10 can change the signal transmission intensity for each physical channel (for example, PUSCH, PUCCH, SRS) according to a control signal commanded by the base station 100. In this case, A gain change of the input signal may occur.

As described above, in the analog beamforming communication system, the beam pattern of the beam and the gain switching can occur very frequently.

In such an analog beamforming communication system, an unforeseeable unstable signal is transmitted through the beam during the physical time (hereinafter referred to as a switching period) that takes place until at least one transition of the beam pattern and gain is initiated after completion of the beam, This can be regarded as a sort of noise signal.

Thus, in the analog beamforming communication system, noise of a very strong intensity is radiated due to a noise signal transmitted through an antenna during a switching period in which at least one of a beam pattern and a gain of a beam is switched, Causing noise in the frequency band of other companies, deteriorating the terminal synchronization performance, causing noise to the adjacent base station in a multi-cell environment, and the like.

However, in the conventional analog beam forming communication system, a method for eliminating noise radiated through an antenna during a switching period in which at least one of a beam pattern and a gain of a beam is switched is not proposed.

Accordingly, the present invention proposes a concrete scheme for eliminating noise radiated through an antenna during a switching period in which at least one of a beam pattern and a gain of a beam is switched in an analog beamforming communication system.

Hereinafter, a signal transmission apparatus for realizing a switching noise elimination scheme proposed in the present invention will be described in detail with reference to FIG.

The signal transmission apparatus according to the preferred embodiment of the present invention is based on the premise that a signal is transmitted through a beam-formed beam, and thus it is assumed that a plurality of antennas are provided.

1, the signal transmission apparatus of the present invention includes an array antenna 140 composed of a plurality of antenna elements to form a beam-formed beam, a plurality of individual antennas So as to form a beam-formed beam.

The signal transmission apparatus of the present invention may be a base station 100 that transmits a signal in downlink, or a terminal 10 that transmits a signal in the case of an uplink.

Hereinafter, for convenience of description, the signal transmission apparatus of the present invention is assumed to be the base station 100 on the assumption of the downlink, and the reference numerals will be referred to.

The signal transmission apparatus 100 according to the preferred embodiment of the present invention includes an RF circuit unit 110 for switching a beam pattern and a gain of a beam, And a noise canceling unit for allowing a specific signal to be transmitted.

Particularly, since the present invention is directed to a communication system adopting analog beam forming technology, the RF circuit unit 110 includes an RF phase shifter 112 for switching a beam pattern and a gain of a beam in a phase shift manner do.

As shown in FIG. 1, the RF circuit unit 110 includes an RF receiver, an RF transmitter, a decoder, and an RF phase shifter.

However, the present invention is intended to remove a beam pattern of a beam and a noise radiated during a switching period for switching a gain, and a reference numeral is designated only for a hardware block involved in a signal transmission (transmission) would.

In addition, although signals processed through each hardware block are converted into digital signals, analog signals, and RF signals in accordance with a process of the signals, for the sake of convenience of explanation, I will collectively.

The decoder 116 decodes an RF control signal (hereinafter, RF command) input from the baseband processing unit 120 in an encoded state and then applies the decoded RF control signal to the RF phase shifter 112.

The RF transmitter 114 processes the transmission signal input from the baseband processor 120 and outputs the RF signal to the RF phase shifter 112.

The RF phase shifter 112 performs a phase shift based on the RF command applied from the Decoder 116 to convert the beam pattern of the beamformed beam formed by the antenna 140 according to the RF command.

The RF phase shifter 112 outputs a transmission signal applied from the RF transmission unit 114 to the RF phase shift unit 112 so that the transmission signal is transmitted through the antenna.

In the signal transmission apparatus 100 of the present invention, the noise canceller maintains a signal transmitted through the antenna during a switching period in which at least one of a beam pattern and a gain of a beam is switched according to the above-described RF command, So that the noise radiated through the antenna is removed by a particular signal.

In the analog beamforming communication system, the physical time until the completion of the beam pattern or gain switching of the beam is required, that is, the time of the switching section is required to be mismatch between the hardware blocks in the RF circuit section 110, And internal delay of the hardware in the RF circuit unit 110. The main reason for this is that the RC (Resistance-Capacitance) delay for transmitting the RF control signal in the RF circuit unit 110 have.

The RF phase shifter 112 for converting (forming) a beamformed beam in an analog manner transmits an applied RF command to each RF chain block in the RF loop block, Physical RC delay is required because of the metal line that carries the RF command to each RF chain block.

The physical RC delay in the RF circuit unit 110 is kept constant under the same switching conditions based on the hardware layout and the metal line specification adopted in the RF circuit unit 110 design process, Do.

Therefore, in the signal transmission apparatus 100 of the present invention, the noise canceller is a system that digitizes and maintains a signal transmitted to the antenna during a known switching period (time of the switching period) as a specific signal, The time of the interval).

On the other hand, in the present invention, an OFDM modulation scheme is used in the analog beamforming communication system, and a more specific embodiment will be described.

 When the OFDM modulation scheme is used in the communication system, a CP (Cyclic Prefix) interval defined in the specification is copied from the last area of the useful symbol segment of the symbol, and the symbol is pasted to the symbol front to generate the entire symbol (CP segment + Useful symbol interval) The transmission standard is defined.

This CP interval is used to prevent ISI (Inter-Symbol Interference) between adjacent symbols when there are a plurality of delay spreads in a multi-path channel environment.

Hereinafter, embodiments in which the noise canceller is variously realized will be described.

First, according to the first embodiment of the present invention, the noise removing unit outputs a transmission signal to the RF circuit unit 110 so that a transmission signal is transmitted through the antenna in the RF circuit unit 110, The baseband processor 120 may output a specific signal to the RF circuit unit 110 instead of the transmission signal during the switching interval matching time calculated based on the transmission delay time until the signal is transmitted through the antenna after outputting the signal.

That is, in the case of the first embodiment, the baseband processing unit 120 plays a role of the noise removing unit in the signal transmission apparatus 100 of the present invention.

Prior to describing the baseband processing unit 120, the upper level of the baseband processing unit 120 will be described first for convenience of explanation.

The MAC (Media Access Control) 130 transmits RF information of each symbol unit in a subframe used for data transmission to the baseband processing unit 120 and informs it.

In addition, the MAC 130 may inform the baseband processing unit 120 of the type of the subframe or the frame information of the standard in the subframe.

In this case, the RF information receiving unit 122 in the baseband processing unit 120 can receive and store RF information (and frame information) transmitted from the MAC 130.

Therefore, in the baseband processing section 120, based on the RF information (and the frame information), the use purpose, the RX section, the TX section, the beam pattern (direction_beam ), And gain (gain_gain).

Specifically, the baseband processing unit 120 includes a timing generator 121 for generating a clock signal for controlling the entire system.

The description of the baseband processor 120 will also be made by designating reference numerals only for the hardware blocks involved in the process of transmitting (transmitting) signals.

The baseband processor 120 includes a baseband transmitter 124 (hereinafter referred to as a BB transmitter), which is involved in signal transmission, and includes an RF controller 125 and an encoder 127, A DFE 126, and a DAC 128.

The RF control unit 125 generates and outputs an RF control signal (RF Command) based on the clock signal of the timing generator 121.

Specifically, the RF controller 125 can recognize a beam pattern or a specific symbol requiring gain conversion based on the RF information transmitted from the MAC 130, based on the previous information.

The RF control unit 125 generates and outputs an RF control signal according to the RF information of the specific symbol and outputs the RF control signal to the RF circuit unit 110 after being encoded in the encoder 127. [ .

Accordingly, the RF circuit unit 110 will switch the beam pattern and the gain of the beam according to the RF command output from the baseband processing unit 120.

Here, according to a more specific embodiment, in the present invention, the switching period for switching the beam pattern of the beam is set such that, among the plurality of symbols in the subframe used for data transmission, It is preferable that at least one of the beam pattern and the gain is included in the CP section of the specific symbol required to be switched.

That is, the beam pattern of the beam is switched using a part of the specific symbol, which is not the usefulful symbol section used for actual data transmission, that is, the CP section.

In this case, it is preferable to switch the beam pattern of the beam by using the first section in the possible CP section in order to secure the longest available interval for ISI prevention by the delay spread in the CP section.

In this case, the CP interval of a specific symbol requiring switching of at least one of a beam pattern and a gain with respect to a previous symbol may be set to be one of a plurality of samples preliminarily utilized as a CP interval in a symbol, The remaining samples are varied except for the samples.

That is, the CP section of a specific symbol varies in length according to the time of the switching section for switching the beam pattern of the beam (the physical RC delay in the RF circuit section 110 numerically calculated according to the design specification).

The RF controller 125 will now be described in accordance with an embodiment in which a beam pattern of a beam is switched using a part of a CP section of a specific symbol.

When the RF controller 125 recognizes a specific symbol required to switch at least one of the beam pattern and the gain with respect to the previous symbol based on the RF information transmitted from the MAC 130, the RF controller 125 generates an RF control signal The RF phase transducer 112 transmits an RF command to the RF phase shifter 112 based on the time required for the RF phase shifter 112 to output the RF command to the RF phase shifter 112, The output timing is calculated so that the beam pattern or the gain of the beam can be switched according to the RF command in the CP section of the specific symbol, especially in the first section.

For example, the RF control unit 125 transmits the RF Command Encoded by the Encoder 127 to the Decoder 116 in the RF circuit unit 110, (Hereinafter referred to as "B2") RF Command Transfer), and the Decoder 116 decodes the RF Command (hereinafter referred to as "B3") RF Command Decoding.

That is, the RF controller 125 considers the processing time of each hardware block existing between the RF controller 125 and the RF phase shifter 112 and the time when the RF command is transmitted according to the system design, And the required time (B1 + B2 + B3).

The RF control unit 125 generates and outputs an RF command at the calculated output time, and the RF command is encoded in the encoder 127 and then output to the RF circuit unit 110.

Accordingly, the RF circuit unit 110, particularly the RF phase shifter 112, will switch the beam pattern or gain of the beam according to the RF command, and such beam pattern or gain switching may be performed by the CP section of a particular symbol, .

In other words, the RF command output from the RF controller 125 at the output time is applied to the RF phase shifter 112 after the elapse of the required time (B1 + B2 + B3) Command, the beam pattern or gain of the beam is switched in the CP section of the specific symbol, especially in the first section (= switching section).

Referring to FIG. 6, the shape of the symbol defined by the transmission standard can be known.

t ₁ is the CP interval, and t ₃ is the usefulful symbol interval.

In the present invention, since the beam pattern or the gain switching section (t ₄ ) is used as a part of the CP section (t ₁ ) defined in the specific symbol for which the beam pattern or the gain change occurs relative to the previous symbol, It can be seen that the CP interval (t ₅ ) in which the CP is transmitted varies in length according to t ₁ - t ₄ .

The BB transmission unit 124 generates a transmission signal based on the clock signal of the timing generator 121 and outputs the transmission signal so that the transmission signal is transmitted from the RF circuit unit 110 through the antenna.

The BB transmitter 124 can recognize a specific symbol requiring conversion of at least one of a beam pattern and a gain with respect to a previous symbol based on the RF information transmitted from the MAC 130.

The BB transmission unit 124 may transmit a specific symbol instead of the transmission signal during the switching interval matching time calculated based on the position of the switching interval and the transmission delay time required for transmission through the antenna after the transmission signal is output And outputs a signal to the RF circuit unit 110.

More specifically, when a specific symbol is recognized, the BB transmitting unit 124 outputs the output time at which the RF command is output from the RF controller 125 and the required time (B1 + B2 + B3) determined by the RF controller 125 And recognizes the position of the switching section on the basis.

As described above, the time of the switching section (the physical RC delay in the RF circuit section 110, which is numerically expressed in accordance with the design specification) is calculated by the BB transmitting section 124 as the time of the switching section Can be known through tabulated / stored information or through interworking with the MAC 130.

Also, the BB transmission unit 124 can know the required time (B1 + B2 + B3) and the RF Command output time.

Accordingly, the BB transmitting unit 124 recognizes the position (starting point of the switching section) plus the required time (B1 + B2 + B3) at the time of output of the RF command as the position of the switching section (= CP section start position of the specific symbol) .

Then, the BB transmission unit 124 transmits a transmission delay time from the position of the switching section recognized (= the CP section start position of the specific symbol) recognized until the transmission signal output by itself to the BB transmission through the antenna is output (-), and the switching interval matching time can be calculated by reflecting the time of the switching interval.

For example, the BB transmission unit 124 transmits the sum of the processing time of the DFE 126 (hereinafter referred to as A1) and the processing time of the DAC 128 (hereinafter referred to as A2) DAC Latency) to the transmission delay time Can be confirmed.

 That is, in consideration of the processing time of each hardware block in the baseband processing unit 120, the transmission signal output from the BB transmission unit 124 according to the system design is multiplied by the transmission delay time ( A1 + A2).

Then, the BB transmitter 124 decodes the transmission delay time (A1 + A2) from the position of the switching section (= CP section start position of the specific symbol) identified earlier and sets the starting point of the switching section matching time (B1 + B2 + B3 - ((A1 + A2)), and the switching interval matching time can be calculated by reflecting the time B4 of the switching interval.

Accordingly, the BB transmitting unit 124 outputs a specific signal to the RF circuit unit 110 instead of the transmission signal during the calculated switching section matching time.

Here, the specific signal is preferably an O-level digital signal.

In this case, while the RF phase shifter 112 switches the beam pattern or gain of the beam in the CP section of the specific symbol, particularly in the first section (= switching section) according to the RF command, The specific signal output during the matching time is applied to the RF phase shifter 112 via the RF transmitter 114 after the elapse of the transmission delay time (A1 + A2), and is transmitted through the antenna.

At this time, the specific signal transmitted through the antenna is an O-level digital signal, so that the noise radiated through the antenna during the switching period for switching the beam pattern or gain of the beam is eliminated.

Referring to FIG. 4, a description will be made of a situation where the noise radiated during the switching period is removed according to the first embodiment described above.

The BB Clock means a clock signal of the Timing Generator 121 used in the BB transmission unit 124 and the RF Clock means a clock signal of the Timing Generator 121 used in the RF Control Unit 125. [

The BB signal means a transmission signal output from the BB transmission unit 124 and the Tx signal means a transmission signal output from the baseband processing unit 120, particularly the DAC 128. The RF command is transmitted to the RF control unit 125, And the RF signal refers to a transmission signal output from the RF circuit unit 110, in particular, the RF phase shifter 112.

In FIG. 4, it is assumed that a specific symbol is required to be switched to the direction_beam # 2 and gain_gain # 2 beam patterns with respect to the previous symbol forming the beams of the direction_beam # 1 and gain_gain # 1 beam patterns .

4, the RF command output from the RF controller 125 is applied to the RF phase shifter 112 after the elapse of the required time (B1 + B2 + B3), and the RF phase shifter 112 According to the RF command, the beam pattern or gain of the beam is switched during the RF transition time (= B4).

On the other hand, the BB transmitter 124 sets the specific signal (0) as the BB signal during the switching section matching time B4 at the starting point (B1 + B2 + B3 - ((A1 + A2)) of the calculated switching section matching time.

4, the specific signal 0 output from the BB transmitter 124 is delayed by the transmission delay time (A1 + A2), and then the RF phase shifter 112 changes the beam pattern or gain of the beam (Tx Signal) to the RF phase shifter 112 via the RF transmitter 114 during a transition period (RF Transition Time, = B4) for switching the RF transition time.

FIG. 3 shows an existing situation in which noise is radiated during a switching period, assuming the same conditions as FIG.

As can be seen from FIG. 3, during the RF transition time (= B4) during which the beam pattern or gain of the beam is switched, it can be seen that the RF signal appears as a noise signal with very strong intensity noise.

However, according to the present invention, as shown in FIG. 4, since the RF signal is maintained at the 0 level during the RF transition time (= B4) for switching the beam pattern or gain of the beam (Zero masking) It will be understood that the noise radiated through the antenna will be eliminated.

Referring to FIG. 7, a case of performing beam pattern or gain switching (RF conversion) in the CP section according to the present invention will now be described.

(CP section + Useful symbol section) defined as a transmission standard is fixedly used for each symbol when the present invention is not applied as shown in (A) of FIG. A symbol pattern defined in a specific symbol (Symbol # 2) requiring switching of at least one of a pattern and a gain will be used. Therefore, even if a first part of the defined CP section is used as a beam pattern or a gain switching section, There will be noise radiated during.

On the other hand, as shown in (B), when the present invention is applied, in a specific symbol (Symbol # 2) requiring switching of at least one of a beam pattern and a gain with respect to a previous symbol (Symbol # 1) It can be seen that there is no noise radiated during this switching period while utilizing the first part of the section as a beam pattern or a gain switching section.

Meanwhile, FIG. 5 shows a situation where the transmission delay time is changed in consideration of a more complicated design in which an analog filter or a digital filter is added in the hardware design of the signal transmission apparatus shown in FIG.

In the hardware design of the signal transmission apparatus shown in FIG. 2, if the analog filter or the digital filter is added, the filter delay time (hereinafter referred to as A3) filter time constant is reflected in the transmission delay time, Adjusting the output point of the output will be more advantageous in terms of maintaining / satisfying the spectrum shape of the overall signal.

As shown in FIG. 5, by increasing the switching interval matching time (zero masking interval) by the time A3 considering the response delay time A3 of the filter, it is possible to more completely remove the noise emitted during the switching interval .

Meanwhile, in the above description, among the hardware blocks in the baseband processing unit 120, the BB transmission unit 124 outputs a specific signal instead of the transmission signal during the switching interval matching time, thereby eliminating the noise radiated through the antenna during the switching period. Is only an embodiment.

In a manner such that the DAC 128 ignores the input transmission signal and outputs a specific signal instead of the transmission signal input during the above-mentioned calculated switching interval matching time in the hardware block other than the BB transmission unit 124 in the baseband processing unit 120, It is also possible to eliminate the noise emitted through the antenna during the transition period.

Meanwhile, according to the second embodiment of the present invention, the RF transmitter 114 can take charge of the role of noise suppression in the signal transmission apparatus 100 of the present invention

That is, while the RF phase shifter 112 switches the beam pattern or gain of the beam in the CP section of the specific symbol, especially in the first section (= transition section) according to the RF command, It is possible to ignore the transmission signal input from the processing unit 120 and transmit a specific signal to the RF phase shifter 112 instead.

Alternatively, the RF transmitting unit 114 may transmit the RF signal to the RF phase shifter 112 while the RF phase shifter 112 switches the beam pattern or gain of the beam in the CP section of the specific symbol, particularly in the first section (= switching section) It is possible to stop the function itself.

In this case, as in the first embodiment, since the specific signal transmitted through the antenna is at the O level or there is no signal transmitted through the antenna, during the switching period for switching the beam pattern or gain of the beam, It is the same as the noise that is radiated through is eliminated.

As compared with the first embodiment and the second embodiment proposed in the present invention, in the case of the second embodiment, an additional circuit is required in the RF circuit unit 110 to increase the designing difficulty. As a result, due to the characteristics of a very high frequency RF design, (Error Vector Magnitude) performance may be somewhat reduced.

After the system design is completed, there is no further function modification or modification, and it is difficult to consider the influence of signal processing such as a filter that may occur at the modem end.

On the other hand, in the case of the first embodiment, it is possible to maintain the complexity and the EVM performance of the RF circuit unchanged because it is not necessary to modify the RF circuit unit 110. Further, even after the system design is completed through cooperation with the upper- This is possible. Also, it is possible to cope with the influence of the spectrum generated by the signal processing inside the modem.

As a result, both the first embodiment and the second embodiment proposed in the present invention have the effect of eliminating the noise radiated during the switching section for switching the beam pattern or gain of the beam, but the complexity of the RF circuit and the EVM performance / It can be said that the first embodiment is more preferable in terms of the possibility of correspondence after the completion of the design.

As described above, the signal transmission apparatus of the present invention is capable of suppressing the noise radiated through the antenna during the switching period in which at least one of the beam pattern and the gain of the beam is switched in the analog beamforming communication system, Problems such as causing noises in the frequency bands of other companies in the same frequency band, causing deterioration in the terminal synchronization performance, causing noise to the adjacent base stations in a multi-cell environment, etc., and improving system performance Effect.

Hereinafter, a signal transmission method according to a preferred embodiment of the present invention will be described in detail with reference to FIG.

For convenience of explanation, the base station 100 will be described as a signal transmission apparatus in accordance with the above description.

In the signal transmission method of the base station 100 according to the present invention, the time (RF transition time) of the transition period digitized for each design specification is tabulated and created (S100).

In the signal transmission method of the base station 100 according to the present invention, RF information of each symbol unit is transmitted to the baseband processing unit 120 and notified (S110).

It is preferable that the performing entity in steps S100 and S110 is the MAC 130 in the base station 100. [

Therefore, in the baseband processing section 120, based on the RF information (and the frame information), the use purpose, the RX section, the TX section, the beam pattern (direction_beam , Gain_gain) and so on.

The signal transmission method of the base station 100 according to the present invention determines whether a particular symbol is required to switch at least one of a beam pattern and a gain with respect to a previous symbol for each symbol based on RF information at step S120.

If the signal is not a specific symbol (No in S120), the signal transmission method of the base station 100 according to the present invention may generate and output a signal to be transmitted (S125).

Meanwhile, in the signal transmission method of the base station 100 according to the present invention, when a specific symbol (Yes in S120), an RF control signal, that is, an RF command is generated and output (S130, S140) (S170, S180, S190, S200).

It is preferable that the performing entity in steps S120 to S140 and S170 to S200 is the baseband processing section 120 (BB) in the base station 100.

Hereinafter, the RF command generation and output processes S130 and S140 and the specific signal generation and output processes S170, S180, S190, and S200, which are performed in parallel with each other, will be described.

The signal transmission method of the base station 100 according to the present invention is a method of generating and outputting an RF command when the specific symbol is recognized (S120 Yes) (B1 + B2 + B3) required to be inputted to the RF phase shifter 112 in the RF circuit unit 110 more specifically than the RF circuit unit 110 after the RF signal is outputted from the RF phase shifter 112, 112) receives the RF command and calculates the output time point at which the beam pattern or gain of the beam can be switched according to the RF command in the CP section, particularly the first section, of the specific symbol (S130).

In the signal transmission method of the base station 100 according to the present invention, the RF controller 125 generates and outputs an RF command at the calculated output time, and the RF command is encoded in the encoder 127, 110 (S140).

It is preferable that the above-mentioned RF command generation and output process main body is an RF control unit 125 in the baseband processing unit 120 (BB).

The RF command is decoded by the Decoder 116 of the RF circuit unit 110 (S150), and the RF command is applied to the RF phase shifter 112.

Therefore, the RF circuit unit 110, particularly the RF phase shifter 112, starts to switch the beam pattern or gain of the beam in accordance with the RF command, and this beam pattern or gain switching is performed in the CP section of the specific symbol, Lt; / RTI > (S160).

In other words, the RF command output from the RF controller 125 at the output time is applied to the RF phase shifter 112 after the elapse of the required time (B1 + B2 + B3) Command, the beam pattern or gain of the beam is switched in the CP section of the specific symbol, especially in the first section (= switching section).

The signal transmission method of the base station 100 according to the present invention is a method in which the RF control unit 125 determines whether a specific symbol is recognized (S120 Yes) (B1 + B2 + B3), which is determined by the RF controller 125, at step S170.

That is, in the signal transmission method of the base station 100 according to the present invention, the position (starting point of the switching section) obtained by adding the required time (B1 + B2 + B3) Section start position).

In the signal transmission method of the base station 100 according to the present invention, after the transmission signal output from the BB transmission unit 124 is outputted from the position of the switching period recognized (= CP segment start position of the specific symbol) (-), and the switching interval matching time may be calculated by reflecting the time of the switching interval (S180).

For example, the signal transmission method of the base station 100 according to the present invention is a method in which the DFE latency of the DFE 126, the processing time of the DAC 128 (hereinafter referred to as A2), and the DAC latency The sum can be confirmed by the transmission delay time.

 That is, in the signal transmission method of the base station 100 according to the present invention, in consideration of the processing time of each hardware block that the transmission signal output from the BB transmission unit 124 in the baseband processing unit 120 according to the system design, And confirms the sum by the transmission delay time (A1 + A2).

The signal transmission method of the base station 100 according to the present invention reduces the transmission delay time (A1 + A2) from the position (= CP section start position of the specific symbol) The starting point of the matching time (B1 + B2 + B3 - ((A1 + A2)) is calculated, and the switching section matching time is calculated by reflecting the time B4 of the switching section.

In the signal transmission method of the base station 100 according to the present invention, the BB transmitter 124 outputs a specific signal (e.g., 0 level digital signal) instead of the transmission signal during the calculated switching section matching time (S190, Zero masking)

The specific signal is output to the RF circuit unit 110 by the DFE 126 and the DAC 128 (S200).

It is preferable that the BB transmission unit 124 in the baseband processing unit 120 (BB) performs the process of generating and outputting the specific signal.

In this case, while the RF phase shifter 112 of the RF circuit unit 110 switches the beam pattern or gain of the beam in the CP section of the specific symbol, particularly in the first section (= switching section) according to the RF command (S160) , The specific signal output by the BB transmitting unit 124 during the switching section matching time is applied to the RF phase shifter 112 via the RF transmitting unit 114 after the elapse of the transmission delay time (A1 + A2).

Therefore, since the signal transmitted through the antenna during the switching period for switching the beam pattern or gain of the beam in the RF phase shifter 112 is an O-level digital signal, the noise actually radiated through the antenna during the switching period is eliminated (S210).

Thus, according to the signal transmission method of the present invention, in the analog beamforming communication system, by removing the noise radiated through the antenna during the switching period in which at least one of the beam pattern and the gain of the beam is switched, And the system performance is improved.

The signal transmission method according to an exemplary embodiment of the present invention may be implemented in the form of a program command that can be executed through various computer means and recorded in 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 medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media 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 machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

According to the signal transmission apparatus and the signal transmission method according to the present invention, in the analog beamforming communication system, in the point that at least one of the beam pattern and the gain of the beam is removed, It is not only the use of the related technology but also the possibility of commercialization or operation of the applied device is sufficient as well as it is possible to carry out clearly and realistically.

10: Terminal
100: base station
110: RF circuit unit 120: baseband processing unit
130: MAC

Claims (9)

A signal transmission apparatus for transmitting a signal through a beam-formed beam,
An RF circuit portion for switching a beam pattern and a gain of the beam; And
And a noise eliminator for transmitting a specific signal through the antenna during a switching period in which at least one of the beam pattern and the gain of the beam is switched. The method according to claim 1,
The noise-
And outputting a transmission signal to the RF circuit unit so that the transmission signal is transmitted through the antenna in the RF circuit unit,
A baseband signal output unit for outputting a specific signal to the RF circuit unit instead of the transmission signal during a switching interval matching time calculated based on a position of the switching unit and a transmission delay time required for transmission through the antenna after the transmission signal is outputted, Wherein the signal processing unit is a processing unit. The method according to claim 1,
The noise-
A transmission signal input to the RF circuit unit is transmitted through the antenna,
Wherein the RF signal transmitter is an RF signal transmitter for transmitting a specific signal instead of the input transmission signal or stopping transmission of a transmission signal during the switching period. 3. The method of claim 2,
In the switching period,
A CP (Cyclic Prefix) of a specific symbol required to switch at least one of a beam pattern and a gain with respect to a previous symbol based on predefined symbol unit RF information among a plurality of symbols in a subframe used for data transmission, , And is defined as a separate interval included in the interval or excluded from the CP interval. 5. The method of claim 4,
The CP interval of the specific symbol is,
And the remaining samples are excluded from a plurality of samples previously defined for use as a CP section in a symbol except for samples from an earliest sample to a sample in which the transition section is accommodated. 5. The method of claim 4,
Wherein the baseband processor comprises:
And outputting an RF control signal according to the RF information of the specific symbol to the RF circuit unit when the specific symbol is recognized so that the RF circuit unit switches at least one of a beam pattern and a gain of the beam according to the RF control signal,
And an RF control unit for outputting the RF control signal at an output time calculated based on a time required until the RF control signal is input to the RF circuit unit after outputting the RF control signal. The method according to claim 6,
Wherein the baseband processor comprises:
When the specific symbol is recognized, a position of the switching section is recognized based on an output time at which the RF control signal is output,
And a transmission signal output section for outputting the specific signal instead of the transmission signal to the RF circuit section during a switching section matching time calculated based on the time of the switching section, the position of the switching section, and the transmission delay time Signal transmission device. 3. The method of claim 2,
The specific signal may be,
O level digital signal. A signal transmission method of a device for transmitting a signal through a beamformed beam,
A recognizing step of recognizing a position of a switching section in which at least one of a beam pattern and a gain of the beam is switched in an RF circuit section;
Calculating a switching interval matching time based on a position of the switching section and a transmission delay time until transmission signals output from the baseband processing section are transmitted through the antenna; And
And outputting a specific signal during the switching section matching time in the baseband processing section and transmitting the specific signal through the antenna during the switching section.

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