KR101783614B1 - The user equipment apparatus for transmitting simultaneously from a plurality of dual band wireless communication scheme and method for dual band transmission thereof - Google Patents

Abstract

The present invention provides a wireless communication system including a first wireless communication unit for transmitting a first signal in a first communication scheme, a second wireless communication unit for transmitting a second signal in a second communication scheme, and a control unit for controlling the first wireless communication unit and the second wireless communication unit And determines whether the first frequency band of the first wireless communication unit is a combination of interference and distortion (IMD) effects with the second frequency band of the second wireless communication unit, Wherein the control unit adjusts an offset of a resource block associated with the second frequency band to prevent the intermodulation distortion if the combination is a combination of two frequency bands and the intermodulation distortion effect, Terminal.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a terminal device for simultaneously transmitting signals in a plurality of wireless communication chips to which a dual-band communication method is applied, and a dual- band transmission thereof}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an offset control of a resource block of a terminal apparatus, and more particularly to a method of controlling offset of a resource block of a terminal apparatus for simultaneously transmitting signals in a plurality of wireless communication chips to which different wireless communication systems are applied will be.

With the remarkable development of wireless communication technology, the use of radio waves has increased in demand, and is widely used not only in the communication and broadcasting fields but also in daily life of medical, traffic and surrounding.

Conventionally, in a wireless communication system, a case where a dual band signal is simultaneously transmitted in a licensed band has not occurred. However, the development of wireless communication technology and the use of radio waves are required to use voice service (Data Service) and data service (Data Service) by using licensed band as the demand increases.

Accordingly, in the case of a terminal supporting a dual band, there is a scenario in which a voice service and a data service are simultaneously transmitted through a dual band. At this time, in the related art, the two antennas are designed to have a structure in which they transmit and receive, respectively, resulting in a problem of intermodulation distortion (IMD), which causes considerable deterioration of reception sensitivity of a specific band .

However, there is no way to solve this problem.

SUMMARY OF THE INVENTION The present invention provides a terminal device capable of simultaneously transmitting signals from a plurality of wireless communication chips to which different wireless communication methods are applied.

According to another aspect of the present invention, there is provided a method of controlling an offset of a resource block allocated to a terminal capable of simultaneously transmitting a signal in a plurality of wireless communication chips to which different wireless communication systems are applied.

The technical problems to be solved by the present invention are not limited to the technical problems and other technical problems which are not mentioned can be understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a mobile terminal including a first wireless communication unit that transmits a first signal in a first communication mode, a second wireless communication unit that transmits a second signal in a second communication mode, And a control unit for controlling the first wireless communication unit and the second wireless communication unit so that the first frequency band of the first wireless communication unit influences InterModulation Distortion (IMD) with the second frequency band of the second wireless communication unit And if the first frequency band is a combination of the second frequency band and the intermodulation distortion effect, a resource block related to the second frequency band is used to prevent intermodulation distortion, And the control unit adjusts the offset of the output signal.

The first wireless communication unit transmits a voice signal, and the first communication method includes a Code Division Multiple Access (CDMA) method.

The second wireless communication unit transmits a data signal, and the second communication method includes an LTE (Long Term Evolution) method.

The control unit determines the sum of the transmission power of the first signal and the transmission power of the second signal and adjusts the offset of the resource blocks only when the sum of the transmission powers is equal to or greater than a predetermined threshold value .

Alternatively, a base station determines an offset of the resource block for preventing the intermodulation distortion, and the controller adjusts the offset of the resource block according to the determination of the base station.

According to another aspect of the present invention, there is provided a dual band transmission method for initiating wireless communication in a dual band, the method comprising: transmitting a first signal in a first communication mode; And determining whether the first frequency band to which the first signal is transmitted is a combination that affects an InterModulation Distortion with a second frequency band to which the second signal is transmitted Wherein the first frequency band is a combination of the second frequency band and the intermodulation distortion effect, and the second frequency band is a combination of the resource blocks related to the second frequency band to prevent the intermodulation distortion. And adjusting the offset.

According to the transmission power control method of a terminal and a terminal according to the present invention, it is possible to remarkably improve communication performance by eliminating the influence of IMD which may occur when signals are simultaneously transmitted from a plurality of wireless communication chips to which different wireless communication systems are applied have.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
1 is a diagram showing an example of a configuration of a terminal 100 according to the present invention.
FIG. 2 is a graph illustrating an operation of generating IMD when different wireless communication schemes are applied according to the present invention. FIG.
3 is a flowchart showing a flow of a method for controlling a resource block allocated to a terminal 100 according to the present invention.
Figure 4 illustrates an example of a method for adjusting the offset of a resource block in accordance with the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without these specific details.

In some instances, well-known structures and devices may be omitted or may be shown in block diagram form, centering on the core functionality of each structure and device, to avoid obscuring the concepts of the present invention. In the following description, the same components are denoted by the same reference numerals throughout the specification.

In addition, in the description of the present invention, a terminal may be a moving or fixed type mobile station such as a user equipment (UE), a mobile station (MS), an advanced mobile station (AMS), a mobile handset, All of the communication devices used by the user of the mobile communication terminal. It is also assumed that the base station collectively refers to any node at a network end that communicates with a terminal such as a Node B, an eNode B, a BS (Base Station), and an AP (Access Point).

The term "wireless communication system" in the present invention may be referred to as various forms such as a radio access technology (RAT) system. Examples of the wireless communication system or the wireless access technology system include a Code Division Multiple Access (CDMA), a Wideband Code Division Multiple Access (WCDMA), and a Long Term Evolution (LTE).

In a wireless communication system, a terminal can receive a signal through a downlink from a base station, and the terminal can also transmit a signal through an uplink. The information transmitted or received by the terminal includes data and various control information, and various physical channels exist depending on the type of information transmitted or received by the terminal.

In this specification, the first wireless communication unit and the second wireless communication unit may be composed of chips for transmitting signals by applying different wireless communication schemes or wireless access technology schemes. Hereinafter, as an example, the first wireless communication unit may be a communication module for transmitting a signal using the CDMA scheme, and the second wireless communication unit may be a communication module for transmitting a signal using the LTE scheme. However, it is not limited to these examples.

1 is a diagram showing an example of a configuration of a terminal 100 according to the present invention.

1, a UE 100 includes a first wireless communication unit 110, a second wireless communication unit 120, a first power amplifier 130, a second power amplifier 140, a first antenna 150, A second antenna 160 and a control unit 180. [

In the wireless communication, a radio wave of a specific frequency band is used. The first and second wireless communication units 110 and 120 modulate the original signal (baseband signal) into a signal of a high frequency band in a signal transmission process, And demodulates the received high-frequency signal into a baseband signal. Each of the wireless communication units 110 and 120 may be implemented as an RF (Radio Frequency) chip that modulates a signal processed in the baseband into a signal in a high frequency band, and may include a baseband chip for processing a baseband signal, RF < / RTI > and a baseband chip "in which an RF chip that modulates a signal processed in the baseband into a high frequency band or demodulates the received signal into a low frequency band and processes it as a baseband signal.

Also, the first and second wireless communication units 110 and 120 may be implemented as separate chips as shown in FIG. 1, or may be implemented as a single chip.

As described above, the first wireless communication unit 110 and the second wireless communication unit 120 process the original signal into a signal of a high frequency band during the signal transmission process, and conversely, during the signal reception process, Signal processing and modulation / demodulation functions, respectively.

When the terminal 100 needs to simultaneously transmit signals at a plurality of wireless communication units 110 and 120 to which different wireless communication systems are applied, the first wireless communication unit 110 converts the original signal into a signal of the first frequency band And at the same time, the second wireless communication unit 120 can perform a function of processing the original signal into the signal of the second frequency band. That is, the terminal 100 can transmit signals by modulating signals in different frequency bands in the first and second wireless communication units 110 and 120 during signal transmission. In general, when the terminal 100 simultaneously transmits signals processed by the first and second wireless communication units 110 and 120, the terminal 100 can transmit signals through different frequency bands.

An interface (not shown) is connected between the first wireless communication unit 110 and the second wireless communication unit 120 as well as between the components in the terminal 100 to exchange signals and information.

The first power amplifier (PA) 130 amplifies the received signal processed by the first wireless communication unit 110 and the second power amplifier 140 amplifies the received signal by the second wireless communication unit 120 Each processed (especially processed in different frequency bands) to amplify the received signal. Signals processed or received in each band are transmitted and received through the first antenna 150 and the second antenna 160, respectively.

The control unit 180 can perform transmission and reception of the terminal 100 and enable communication in various environments. The control unit 180 may include a receiving module having a receiving signal filtering filter and a transmitting module having a power amplifier for amplifying the transmitting signal.

In addition, the controller 180 may be used to transmit a signal through multiple frequency bands, such as the terminal 100 described in the present invention. For example, the control unit 180 enables the terminal 100 to use the GSM system and the W-CDMA system at the same time. The number of parts of the terminal 100 can be reduced through the function of the controller 180 and the reliability of the terminal 100 can be increased and the loss due to interconnection between components can be reduced.

The control unit 180 can reduce power consumption, dramatically improve battery consumption, and enable miniaturization of components of multiple frequency bands and multi-function terminals. 1, the control unit 180 may transmit signals processed in a plurality of frequency bands received from the power amplifier 130 and the power amplifier 140 through the antennas 150 and 160, respectively.

The antennas 150 and 160 transmit signals to an external device (e.g., a base station) and are shown as two in FIG. 1, but the terminal 100 may have one or more antennas.

FIG. 2 is a graph illustrating an operation of generating IMD when different wireless communication schemes are applied according to the present invention.

In the context of the present invention, intermodulation distortion (IMD) is the intermodulation of signals that were not at the input to the output when two or more frequencies pass through a nonlinear system or circuit, It means distortion itself.

These IMDs are important because digital systems such as CDMA do not use one frequency, that is, one channel, unlike an analog system, where multiple signals share wide channel bandwidth. That is, since signals of various frequencies are simultaneously input to a system for processing one band, if signals of various frequencies are mixed with each other at the output terminal, signal processing may not be performed properly.

Referring to Fig. 2 (a), a situation in which an IMD is generated will be described. As shown in the figure, it is assumed that there are two frequencies f1 and f2. Even though there are two frequencies, the output is a mixture of two mixed frequencies. However, complete drainage harmonies such as 2 * f1, 3 * f2 can be filtered.

However, the problem is the 3 rd order, 2 * f1-f2 and 2 * f2-f1, which is problematic because the signals f1 and f2 are very close together. In Fig. 2 (a), the presence of the third-order 2 * f1-f2 and 2 * f2-f1 in addition to the two frequencies f1 and f2 can be confirmed. The IMD mainly refers to such a third-order intermodulation component. Therefore, the signals usually referred to as IMD often refer to the 3rd order IMD. Typically, the IM, also referred to as the IMD, is also called IM3 alone because the third frequency component is the primary object of removal. In particular, as the input signal increases, the 3rd order IMD increases as the input signal increases. As the input signal increases, the IMD increases at a much faster rate than the original signal, Occurs. The point at which IMD is similar to the original signal power is called IP3.

As such, IMD means the degree of distortion of the signal due to intermodulation, and IP3 is used as the actual product specification or measurement reference value. In the superheterodyne scheme, which uses an intermediate frequency (IF), it is important to eliminate the 3rd IM because the intermodulation is the closest to the original signal. It is therefore desirable to reduce the effects of such signal distortion and interference, such as IMD.

Referring to FIG. 2 (b), a case where frequency bands other than one frequency are the IMD problems will be described. As described above, when there are a plurality of frequencies, IMD, which is a mixed-modulation phenomenon, is generated, and there is also a possibility that IMD is generated when the frequency is transmitted in different frequency bands. However, even if the IMD actually occurs, it does not affect the transmission / reception system altogether. For example, only IMDs above a certain power can cause problems in the respective transmit and receive frequency bands. In addition, when transmitting in different frequency bands, the entire frequency band does not cause IMD, but IMD is more likely to occur due to some of the frequency bands.

Referring to FIG. 2 (b), when transmitting in the first frequency band band 1 and the second frequency band band 2, the entire first frequency band or the entire second frequency band does not generate IMD. For example, the IMD may be influenced only when it is transmitted in a specific band?? Of the first frequency band and a specific band?? Of the second frequency band. Therefore, in the figure, the IMD can affect the communication system when it corresponds to the shaded bands of the two frequency bands.

3 is a flowchart showing a flow of a method of controlling a resource block allocated to a terminal 100 according to the present invention.

The control unit 180 performs the SV-LTE mode (S310). The controller 180 determines whether the sum of the power of the first frequency band and the power of the second frequency band exceeds a predetermined threshold value (S320). If it is not exceeded, a signal is transmitted / received through a normal procedure (S350). If the predetermined threshold value is exceeded, the control unit 180 determines whether the first frequency band includes a band resulting from the IMD (S330). If not, a signal is transmitted / received through a normal procedure (S350). If the first frequency band includes a band that results in IMD, the controller 180 adjusts the offset of the resource block of the second frequency band to prevent IMD generation (S340).

Hereinafter, the present invention will be described with reference to the flowchart of the resource block control method of the mobile station of FIG.

First, in step S310, the controller 180 performs the SV-LTE mode.

SV-LTE mode is a Simultaneous Voice LTE mode, which means a communication mode that can simultaneously provide voice and data. As shown in FIG. 1, two or more different communication methods can be applied to the mobile terminal 100 in hardware. For example, one may be a CDMA 1x system capable of transmitting and receiving voice and the other may be an LTE system capable of transmitting and receiving data. Each of the wireless communication units 110 and 120 is applied with a different communication scheme and does not affect each other. However, as described above, there may be a problem of IMD.

The control unit 180 performs the SV-LTE mode when the communication mode of the mobile terminal 100 is the dual-band mode, in which the present invention is applied to the dual-band mode in which the different communication schemes are applied.

In step S320, the controller 180 determines whether the sum of the power of the first frequency band and the power of the second frequency band exceeds a specific threshold value.

There are various factors that affect the transmission and reception signals of the IMD. For example, depending on the frequency of each of the dual bands, the IMD may determine whether it affects actual signal transmission or reception, or the IMD may affect the power of each signal in the dual band.

As shown in FIG. 2, each of the signals of the dual band has a constant power, and the signal generated according to the IMD also has a constant power. Generally, the signal generated in accordance with the IMD is affected by the power of each signal of the dual band, that is, the power of the first signal of the first wireless communication section rotor and the power of the second signal from the second wireless communication section.

Experimentally, it is known that the sum of the power of the first signal and the power of the second signal exceeds a certain level in order to cause a problem that the IMD affects the actual signal transmission / reception. Since the present invention is applied to the case where the IMD affects actual signal transmission and reception, if the sum of the powers is smaller than a predetermined threshold value, it is possible to transmit and receive signals without adjusting resource blocks through a general process .

Here, the predetermined threshold value is an experimentally determined value, and can be variously determined according to the type of the terminal. For example, the threshold value may be a factor that determines the data sensitivity of the UE to a certain level. For example, if the sum of the power of the first signal and the power of the second signal, which is set by the user or the manufacturer, is -96.5 dBm and the data sensitivity reaches -96.5 dBm is 12 dBm, Is set to 12 dBm.

If the sum of the power does not exceed the specific threshold value, the general signal transmission / reception process is performed through step S350.

In step S330, the control unit 180 determines whether the first frequency band includes a band resulting in IMD.

Referring again to Fig. 2 (b), the entire ([Delta] f1) of the first frequency band (band 1) does not result in IMD. That is, it may result in generating an IMD when it corresponds to a partial band? Of the first frequency band and corresponds to a partial band? Of the second frequency band. Therefore, in the case of a band other than DELTA alpha in the first frequency band, there is no need to adjust the offset of the resource block since the IMD is not a serious problem in the signal transmission and reception process. The present invention can adjust the offset of a resource block related to data communication depending on where the transmission / reception band of the voice signal belongs to the first frequency band.

On the other hand, since two different bands are generated in the dual band situation, the IMD may have a plurality of pairs of the respective frequency bands of the dual band generating the IMD. For example, the a band of the first frequency band and the b band of the second frequency band may generate the IMD, and the c band of the first frequency band and the d band of the second frequency band may generate the IMD.

In step S340, the controller 180 adjusts the offset of the resource block in the second frequency band.

The case where the IMD has passed through the steps S320 and S330 can affect the actual signal transmission / reception process. The controller 180 needs to adjust the band used for transmitting and receiving the data signal in the second frequency band.

In the present invention, as an example for preventing IMD, the offset of the resource block of the second frequency band that is the data communication band can be adjusted.

Referring again to FIG. 2 (b), even if voice communication is transmitted / received in the first frequency band, if the data is transmitted / received in a band not corresponding to? In the second frequency band, the possibility of IMD being affected is significantly reduced . Accordingly, the controller 180 may select a method of adjusting the offset of the resource block in a manner of changing a part of the frequency band.

FIG. 4 is a diagram illustrating an example of a method of adjusting an offset of a resource block according to the present invention.

The structure of the resource block will be schematically described with reference to Fig. 4 (a). The mobile terminal 100 can set up 50 resource blocks during signal transmission / reception. Therefore, RB # 0, RB # 1, ... 50 resource blocks up to RB # 48 and RB # 49 can be set for data transmission / reception. Each resource block is composed of one slot and 12 subcarriers. One slot is composed of seven symbols. Various data are allocated and transmitted to a resource element (RE) composed of one symbol and one subcarrier.

One subcarrier is 15 kHz, and one resource block consisting of 12 subcarriers is 180 kHz. Also, since the terminal can set 50 resource blocks, the frequency band of 50 x 180 kHz = 9 MHz can be set as the data communication band. That is, the data communication band used in the second frequency band can be set to a band of approximately 9 MHz.

The control unit 180 may exclude a band that results in IMD in relation to the first frequency band of the second frequency band used.

Referring to FIG. 4B, an operation of adjusting an offset of a resource block among 50 resource blocks (RBs) allocated to a terminal is shown. If there is no frequency band for generating the IMD among the first frequency bands, all 50 resource blocks among the second frequency band can be selected without restriction. However, since it is determined that a specific band of the first frequency band generates the IMD, the offset of 50 resource blocks of the second frequency band is set to a specific offset. In the drawing, resource blocks are set to be allocated from the third resource block out of 50 resource blocks. If a specific frequency band (for example, 45 to 55 channels) of the first frequency band is a problem between the RB # 0 to RB # 2 and the IMD in the second frequency band, the controller 180 controls the RB # 0 to RB # 2 are excluded. Therefore, in the figure, the offset of the resource block is set to 3, and data resources are allocated from the RB # 3 and are set to transmit and receive signals.

On the other hand, as described above, since there may be several pairs of bands in which the IMD is a problem, another offset setting is required accordingly. For example, if the specific band (1003 to 1023Ch) of the first frequency band has room for generating the specific band (RB # 0 to RB # 13) and the IMD of the second frequency band, It can be set to # 14. If the specific band (21 to 41Ch) of the second frequency band has room for generating the specific band (RB # 0 to RB # 5) and the IMD of the second frequency band, the controller (180) RB # 6. Finally, if the specific band 45 to 55Ch of the second frequency band has room to generate the specific band RB # 0 to RB # 2 and the IMD of the second frequency band, the controller 180 sets the offset of the resource block Can be set to RB # 3. On the other hand, the specific band of the first frequency and the specific band of the second frequency band in which the IMD is a problem are exemplary and can be determined experimentally.

In the above description, the control unit 180 of the mobile terminal 100 has been described as controlling the offset of the resource block. The control unit 180 can set the offset of the resource blocks by checking the actual frequency bands of the first wireless communication unit 110 and the second wireless communication unit 120 of the mobile terminal 100. [ However, in another way, the base station that determines the offset of the resource block of the second frequency band may be the base station. For example, a base station transmitting and receiving a voice or data signal with the mobile terminal 100 can confirm the frequency band of the mobile terminal 100. In addition, the base station can easily identify a frequency band in which there is an error or a load, and the base station can efficiently check the first frequency band and the second frequency band where IMD may occur. Accordingly, the BS may perform the offset adjustment of the resource block by the controller 180. [ In this case, information related to the offset adjustment of the resource block by the base station may be added to the transmission / reception signal of the base station and the terminal 100. [

Embodiments in accordance with the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs) Field Programmable Gate Arrays), a processor, a controller, a microcontroller, a microprocessor, or the like.

In the case of an implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, a procedure, a function, or the like which performs the functions or operations described above. The software code can be stored in a memory unit and driven by the processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various well-known means.

The embodiments described above are those in which the elements and features of the present invention are combined in a predetermined form. Each component or feature shall be considered optional unless otherwise expressly stated. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to construct embodiments of the present invention by combining some of the elements and / or features. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is clear that the claims that are not expressly cited in the claims may be combined to form an embodiment or be included in a new claim by an amendment after the application.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

100 mobile terminal 110 first wireless communication section
120 second wireless communication unit 130 first power amplifier
140 second power amplifier 180 control unit

Claims (13)

A first wireless communication unit for transmitting a first signal of a first frequency band using a first communication scheme;
A second wireless communication unit for transmitting a second signal of a second frequency band using a second communication scheme; And
A sum of transmission power of the first signal and transmission power of the second signal is calculated and it is determined whether the sum of the calculated transmission powers exceeds a predetermined threshold value, Determining whether the first frequency band includes a band that results in Inter Modulation Distortion (IMD) if the threshold value is exceeded, and if the first frequency band causes the intermodulation distortion Wherein the control unit adjusts the offset of the resource blocks associated with the second frequency band to prevent intermodulation distortion,
Mobile terminal. The method according to claim 1,
Characterized in that the first wireless communication unit transmits a voice signal.
Mobile terminal. The method according to claim 1,
Wherein the first communication scheme includes a Code Division Multiple Access (CDMA) scheme,
Mobile terminal. The method according to claim 1,
And the second wireless communication unit transmits a data signal.
Mobile terminal. The method according to claim 1,
Wherein the second communication scheme includes an LTE (Long Term Evolution) scheme,
Mobile terminal. delete The method according to claim 1,
A base station determines an offset of the resource block to prevent the intermodulation distortion,
Wherein the control unit adjusts the offset of the resource block according to the determination of the base station.
Mobile terminal. A method for initiating wireless communication in a dual band, the method comprising: transmitting a first signal of a first frequency band to a first communication scheme and transmitting a second signal of a second frequency band to a second communication scheme; Initiation step;
Calculating a sum of a transmission power of the first signal and a transmission power of the second signal;
Determining whether the sum of the calculated transmit powers exceeds a predefined threshold;
Determining whether the first frequency band includes a band causing Intermodulation Distortion (IMD) if the sum of the transmission powers exceeds the threshold value; And
Adjusting an offset of resource blocks associated with the second frequency band to prevent intermodulation distortion if the first frequency band includes a band resulting from the intermodulation distortion; / RTI >
Dual band transmission method. delete delete delete delete delete

Images