Communication device and envelope delay optimization method supporting envelope tracking modulation

Abstract

A communication device supporting envelope tracking modulation and an envelope delay optimization method are provided. The method includes estimating adjacent channel leakage ratios respectively corresponding to a plurality of test delay values based on a test output signal output from a power amplifier according to a test input signal corresponding to the plurality of frequencies, selecting a test delay value corresponding to a maximum value among the estimated adjacent channel leakage ratios, and providing a supply voltage to the power amplifier based on an envelope signal delayed according to the selected test delay value. For each of the plurality of test delay values, the corresponding adjacent channel leakage ratio is estimated based on a ratio of an amplitude of a component included in the test output signal to an amplitude of an intermodulation component.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2020-0083606, filed on July 7, 2020, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] The methods, apparatuses, and systems consistent with the example embodiments relate to communication devices and envelope delay optimization methods, and more specifically, to communication devices supporting envelope tracking modulation and methods for optimizing envelope delay. Background Technology

[0003] In recent years, significant efforts have been made to improve the efficiency of transmitting devices in user equipment (UE) in order to extend battery life. Furthermore, in-depth research has been conducted in the field of network equipment to reduce heat loss. Various technologies have been developed based on the assumption that the efficiency and radio frequency (RF) performance of most transmitting devices are affected by the power amplifier (PA).

[0004] Envelope tracking (ET) is attracting attention and is being studied continuously. Summary of the Invention

[0005] Example embodiments provide a method and apparatus for matching the phase of an input signal and its envelope to improve the efficiency of a power amplifier in a communication device, as well as an envelope delay optimization method.

[0006] According to one aspect of an example embodiment, a method for optimizing the delay value of an envelope is provided. The method includes: in a test mode, estimating a plurality of adjacent channel leakage ratios corresponding to a plurality of test delay values ​​based on a test output signal output from a power amplifier, wherein the test output signal is generated by the power amplifier based on test input signals corresponding to a plurality of frequencies; selecting a test delay value corresponding to the maximum value among the estimated plurality of adjacent channel leakage ratios; and in a normal mode, providing a power supply voltage to the power amplifier based on an envelope signal delayed according to the selected test delay value. The step of estimating the plurality of adjacent channel leakage ratios includes: for each of the plurality of test delay values, estimating the corresponding adjacent channel leakage ratio based on the ratio of the amplitude of the frequency-corresponding components included in the test output signal to the amplitude of the intermodulation components of the test output signal.

[0007] According to one aspect of an example embodiment, a method is provided. The method includes: converting a test output signal from a power amplifier output to the frequency domain, wherein the test output signal is generated based on an input of a single-tone signal corresponding to a selected plurality of frequencies sampled at a sampling rate; obtaining a plurality of aliasing frequencies corresponding to aliased intermodulation components based on the sampling rate and the selected plurality of frequencies; and estimating, in the frequency domain, an adjacent channel leakage ratio based on the amplitudes of the components corresponding to the selected plurality of frequencies and the amplitudes of the components corresponding to the plurality of aliasing frequencies in the converted test output signal.

[0008] According to one aspect of an example embodiment, a communication apparatus is provided. The communication apparatus includes: a modem configured to generate, in a test mode, single-tone signals corresponding to a plurality of selected frequencies as test input signals; a power amplifier configured to generate a test output signal based on the test input signals transmitted via a signal transmission path; a voltage modulator configured to: sequentially generate delayed envelope signals based on each of a plurality of test delay values ​​in the test mode, and sequentially supply power supply voltages to the power amplifier based on the delayed envelope signals according to each of the plurality of test delay values; and a controller configured to: in the test mode, for each of the plurality of test delay values, estimate an adjacent channel leakage ratio based on the amplitudes of components corresponding to the selected plurality of frequencies and the amplitudes of intermodulation components included in the test output signal, select a test delay value corresponding to the maximum value among the estimated plurality of adjacent channel leakage ratios, and control the voltage modulator based on the test delay values ​​in a normal mode.

[0009] According to one aspect of an example embodiment, a method for optimizing the delay value of an envelope is provided. The method includes: providing a single-tone signal corresponding to a selected plurality of frequencies as a test input signal; applying a first power supply voltage to a power amplifier to generate a first test output signal by delaying the envelope signal of the test input signal using a first delay value; estimating a first adjacent channel leakage ratio based on the amplitude of each of a plurality of components included in the first test output signal and the amplitude of aliased intermodulation components; applying a second power supply voltage to a power amplifier to generate a second test output signal by delaying the envelope signal of the test input signal using a second delay value; estimating a second adjacent channel leakage ratio based on the amplitude of each of a plurality of components included in the second test output signal and the amplitude of aliased intermodulation components; and delaying the envelope signal corresponding to a baseband signal according to the first delay value in normal mode based on the first adjacent channel leakage ratio being equal to or greater than the second adjacent channel leakage ratio, and delaying the envelope signal corresponding to the baseband signal according to the second delay value in normal mode based on the first adjacent channel leakage ratio being less than the second adjacent channel leakage ratio.

[0010] According to one aspect of an example embodiment, a method for optimizing the delay value of an envelope is provided. The method includes: in a test mode, providing a modulated power supply voltage to a power amplifier using a plurality of test delay values ​​to obtain estimated adjacent channel leakage ratios, each corresponding to one of the plurality of test delay values; and in a normal mode, providing a power supply voltage to the power amplifier based on a delayed envelope signal, wherein the delayed envelope signal is based on a test delay value corresponding to the maximum value among the estimated plurality of adjacent channel leakage ratios. The step of obtaining the estimated plurality of adjacent channel leakage ratios includes: for each of the plurality of test delay values, providing a single-tone signal corresponding to a plurality of selected frequencies to a signal transmission path including the power amplifier; obtaining the amplitude of the component corresponding to the selected plurality of frequencies and the amplitude of aliased intermodulation components by converting a test output signal from the power amplifier to the frequency domain; and estimating the corresponding adjacent channel leakage ratio based on the obtained amplitudes. Attached Figure Description

[0011] The above and other aspects, features, and advantages will become clearer from the following detailed description of exemplary embodiments taken in conjunction with the accompanying drawings, in which:

[0012] Figure 1 This is a diagram of a wireless communication device according to an example embodiment;

[0013] Figure 2A It is a graph of the power supply voltage based on the comparison example;

[0014] Figure 2B It is a graph of the modulated power supply voltage according to the example embodiment;

[0015] Figure 2C It is a graph of the power supply voltage that is not synchronized with the input signal, based on the comparison example;

[0016] Figure 3 This is a flowchart of the envelope delay optimization method according to an example embodiment;

[0017] Figure 4 This is a flowchart of the envelope delay optimization method according to an example embodiment;

[0018] Figure 5A and Figure 5B This is a diagram illustrating the frequency characteristics of a test input signal under a test mode according to an example embodiment;

[0019] Figure 6 This is a diagram illustrating the frequency characteristics of the test output signal under the test mode according to an example embodiment;

[0020] Figure 7This is a diagram illustrating the frequency characteristics of the test output signal under the test mode according to an example embodiment;

[0021] Figure 8 This is a diagram of a controller according to an example embodiment;

[0022] Figure 9 This is a flowchart of the envelope delay optimization method according to an example embodiment;

[0023] Figure 10 This is a flowchart of the envelope delay optimization method according to an example embodiment;

[0024] Figure 11A and Figure 11B This is a flowchart of the envelope delay optimization method according to an example embodiment;

[0025] Figure 12A and Figure 12B This is a diagram illustrating the frequency characteristics of a test input signal under a test mode according to an example embodiment;

[0026] Figure 13 This is a diagram illustrating the frequency characteristics of the test output signal under the test mode according to an example embodiment; and

[0027] Figure 14 This is a diagram of a communication device according to an example embodiment. Detailed Implementation

[0028] In the following description, exemplary embodiments will be described in detail with reference to the accompanying drawings.

[0029] Figure 1 This is a diagram of a wireless communication device 10 according to an example embodiment. The wireless communication device 10 may include a modem 100, a radio frequency integrated circuit (RFIC) 200, a power amplifier 300, a front-end module 400, an antenna 500, a voltage modulator 600, and a controller 700. In some example embodiments, the wireless communication device 10 may also include... Figure 1 Components not shown. For example, switches and / or duplexers controlled according to the transmit or receive mode may be located between the power amplifier 300 and the front-end module 400. Furthermore, in the example embodiment, the controller 700 may be an external device to the wireless communication device 10.

[0030] The wireless communication device 10 can connect to a wireless communication system by transmitting and receiving signals via antenna 500. The wireless communication system to which the wireless communication device 10 is connected may be referred to as a Radio Access Technology (RAT), and by way of non-limiting example, the wireless communication system may be a wireless communication system using a cellular network (such as a fifth-generation wireless (5G) system, a Long Term Evolution (LTE) system, an Advanced LTE system, a Code Division Multiple Access (CDMA) system, a Global System for Mobile Communications (GSM), etc.), or it may be a Wireless Local Area Network (WLAN) system or any other wireless communication system. In the following description, the wireless communication system to which the wireless communication device 10 is connected will be described under the assumption that it is a wireless communication system using a cellular network; however, it will be understood that the exemplary embodiments are not limited thereto.

[0031] The wireless communication network of a wireless communication system can support communication between multiple wireless communication devices, including wireless communication device 10, by sharing available network resources. For example, in a wireless communication network, information can be transmitted using various multiple access methods such as Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), OFDM-FDMA, OFDM-TDMA, and OFDM-CDMA.

[0032] Wireless communication device 10 can refer to any device connected to a wireless communication system. For example, wireless communication device 10 can refer to a base station BS. A base station BS can generally refer to a fixed station used to communicate with user equipment and / or another base station, and can exchange data and control information by communicating with user equipment and / or another base station. For example, a base station can be referred to as a Node B, Evolved Node B (eNB), Next Generation Node B (gNB), sector, site, Basic Transceiver System (BTS), Access Point (AP), Relay Node, Remote Radio Header (RRH), Radio Unit (RU), small cell, etc. In this specification, a base station or cell can have a comprehensive meaning indicating some area or function covered by a Base Station Controller (BSC) in CDMA, a Node B in WCDMA, and an eNB or sector (site) in LTE, and can cover all kinds of coverage areas, such as megacells, macrocells, microcells, picocells, femtocells, relay nodes, RRHs, RUs, and small cell communication ranges.

[0033] For example, wireless communication device 10 may refer to user equipment (UE). UE may be fixed or mobile, and may refer to any device capable of sending and receiving data and / or control information by communicating with a base station. For example, UE may be referred to as terminal equipment, mobile station (MS), mobile terminal (MT), user terminal (UT), user station (SS), wireless device, or handheld device. In this specification, wireless communication device 10 is generally described as a UE, but it will be understood that the exemplary embodiments are not limited thereto.

[0034] Reference Figure 1 Antenna 500 can be connected to front-end module 400 and can transmit signals provided from front-end module 400 to another wireless communication device, or can provide signals received from another wireless communication device to front-end module 400. Figure 1 In this embodiment, some components used for receiving signals from other wireless communication devices via antenna 500 may be omitted. In some example embodiments, wireless communication device 10 may include multiple antennas for phased arrays, multiple-input multiple-output (MIMO), etc.

[0035] Modem 100 can generate a signal including information to be transmitted via antenna 500. In some example embodiments, modem 100 may include an encoder, modulator, filter, digital-to-analog converter (DAC), etc. For example, modem 100 can generate a transmit signal TX and provide the transmit signal TX to RFIC 200 and voltage modulator 600. In an example embodiment, modem 100 can generate a baseband transmit signal in normal mode of wireless communication device 10 and provide the baseband transmit signal to RFIC 200 and voltage modulator 600. In an example embodiment, modem 100 can generate a test input signal INPUT in test mode of wireless communication device 10 and provide the test input signal INPUT to RFIC 200 and voltage modulator 600. Test mode may refer to a mode used to obtain the optimal delay value among multiple test delay values ​​by comparing the respective adjacent channel leakage ratios for multiple test delay values. In an example embodiment, test input signal INPUT is a signal corresponding to multiple frequencies selected from the channel band, and may be, for example, a single-tone signal of at least two selected frequencies. However, the example embodiments are not limited thereto. The test input signal INPUT can include multiple frequency bands, and each of the multiple frequency bands is a unit frequency band generated by the resource block, and can be a frequency band including at least one frequency. (Refer to...) Figure 5A and Figure 5B Describe the test input signal INPUT in more detail.

[0036] RFIC 200A can receive a transmit signal TX from modem 100 and can generate a first RF transmit signal TX_RF1 based on the transmit signal TX. For example, RFIC 200A may include a mixer, filter, and amplifier. RFIC 200A may be included in the signal transmission path on which the transmit signal TX is transmitted and may send the transmit signal TX to power amplifier 300.

[0037] Power amplifier 300 can generate a second RF transmission signal TX_RF2 by amplifying the first RF transmission signal TX_RF1 using power supplied by a modulated power supply voltage V_M. In the test mode of wireless communication device 10, the test input signal INPUT generated by modem 100 is provided to power amplifier 300 via a signal transmission path including RFIC 200A, and power amplifier 300 can output a test output signal OUTPUT based on the test input signal INPUT received via the signal transmission path. Power amplifier 300 can provide the test output signal OUTPUT to controller 700.

[0038] Voltage modulator 600 can modulate the power supply voltage supplied to power amplifier 300 based on an envelope signal ENV generated by detecting the envelope of the transmitted signal TX. For example, voltage modulator 600 can generate a modulated power supply voltage V_M that follows the envelope signal ENV, and can supply the modulated power supply voltage V_M to power amplifier 300. Voltage modulator 600 may include envelope detector 620, delay circuit 640, and power supply 660.

[0039] Envelope detector 620 generates an envelope signal ENV by detecting the envelope of the transmit signal TX provided from modem 100. Envelope detector 620 can provide the envelope signal ENV to delay circuit 640.

[0040] The delay circuit 640 can generate a delayed envelope signal ENV_D based on the delay value DLY provided by the controller 700, and can provide the delayed envelope signal ENV_D to the power supply 660. For example, in test mode, the delay circuit 640 can generate the delayed envelope signal ENV_D by delaying the envelope signal ENV based on each of a plurality of test delay values ​​provided by the controller 700 as the delay value DLY. Furthermore, for example, in normal mode, the delay circuit 640 can generate the delayed envelope signal ENV_D by delaying the envelope signal ENV based on an optimized delay value provided by the controller 700 as the delay value DLY, referring to... Figure 2B and Figure 2C Describe in more detail why the envelope signal ENV needs to be delayed.

[0041] The power supply 660 can generate a modulated power supply voltage V_M based on the delayed envelope signal ENV_D, and can provide the modulated power supply voltage V_M to the power amplifier 300.

[0042] The controller 700 can control the delay circuit 640 based on the delay value DLY. For example, in normal mode, the controller 700 can control the delay circuit 640 by providing an optimized delay value as the delay value DLY. Furthermore, for example, in test mode, the controller 700 can control the delay circuit 640 by providing each of a plurality of test delay values ​​as the delay value DLY to the delay circuit 640.

[0043] In an example embodiment, controller 700 may select one of a plurality of test delay values ​​as the optimized delay value. To this end, in test mode, controller 700 may estimate the adjacent channel leakage ratio based on the test output signal OUTPUT for each of the plurality of test delay values. More specifically, in test mode, controller 700 may provide the test delay value as a delay value DLY to delay circuit 640, voltage modulator 600 may provide a modulated supply voltage V_M of the envelope signal based on the delay of the test delay value to power amplifier 300, and power amplifier 300 may output test output signal OUTPUT by amplifying the test input signal INPUT received via the signal transmission path using the modulated supply voltage V_M. When the test input signal INPUT is a single-tone signal of a selected plurality of frequencies, the test output signal OUTPUT may include a fundamental frequency component and intermodulation components. The fundamental frequency component may indicate the component corresponding to the selected plurality of frequencies. Furthermore, in the example embodiment, the intermodulation components are harmonic components of the selected plurality of frequencies and may include third-order and fifth-order intermodulation components. The controller 700 can estimate the adjacent channel leakage ratio based on the ratio of the amplitude of the fundamental frequency component to the amplitude of the intermodulation component included in the test output signal OUTPUT. In other words, the controller 700 can obtain multiple estimated adjacent channel leakage ratios for multiple test delay values. The controller 700 can select a test delay value corresponding to the largest adjacent channel leakage ratio among the multiple estimated adjacent channel leakage ratios, and can use the selected test delay value as an optimized delay value.

[0044] As technology advances, the bandwidth of the transmitted signal TX continues to widen. To measure the adjacent channel leakage ratio (ADR) of a transmitted signal TX with a wide bandwidth, the wireless communication device according to the comparative example needs to support a high sampling rate. For example, to measure the ADR of a transmitted signal TX with a bandwidth of 100 MHz, the wireless communication device according to the comparative example needs to support a sampling rate of at least 300 MHz. However, enabling the wireless communication device to support high sampling rates requires excessive power consumption or high hardware costs.

[0045] Based on the wireless communication device 10 according to the example embodiment, in test mode, the adjacent channel leakage ratio can be estimated based on the amplitude of the fundamental frequency component and the amplitude of the intermodulation component in the test output signal OUTPUT, which is output according to the input of the test input signal INPUT (such as a single-tone signal corresponding to a plurality of frequencies selected in the channel band). Specifically, when the intermodulation frequency corresponding to the intermodulation component is greater than the sampling rate (or half of the sampling rate), the controller 700 can estimate the adjacent channel leakage ratio based on the amplitude of the fundamental frequency component and the amplitude of the aliased intermodulation component.

[0046] Furthermore, the wireless communication device 10 according to the example embodiment can select an optimized delay value from a plurality of test delay values ​​by estimating the adjacent channel leakage ratio for a plurality of test delay values, and in normal mode, the transmitted signal TX can be synchronized with the envelope signal ENV by controlling the delay circuit 640 based on the optimized delay value. Therefore, the efficiency of the power amplifier 300 can be improved.

[0047] Figure 2A It is a graph of the power supply voltage based on the comparison example. Figure 2A The graph shows the transmitted signal TX and the power supply voltage over time when the power supply voltage applied to the power amplifier is constant.

[0048] When the power supply voltage applied to the power amplifier is constant, because the value of the power supply voltage needs to be greater than the maximum value of the transmitted signal TX, there is a time period in which the difference between the transmitted signal TX and the power supply voltage widens.

[0049] Therefore, heat loss occurs in the curve in the amount corresponding to the region 50a between the power supply voltage line and the transmitted signal TX.

[0050] Figure 2B This is a graph of the modulated power supply voltage according to an example embodiment. Specifically, Figure 2B A graph showing the first RF transmission signal TX_RF1 and the modulated power supply voltage over time is shown according to an example embodiment when a modulated power supply voltage is applied to the power amplifier 300. (Refer to...) Figure 1 describe Figure 2B .

[0051] According to an example embodiment, a voltage modulator 600 included in a wireless communication device 10 can detect an envelope signal ENV from a transmitted signal TX and can generate a modulated power supply voltage V_M such that the modulated power supply voltage V_M follows the envelope of the transmitted signal TX.

[0052] Therefore, it can be seen that, with Figure 2ACompared to region 50a, region 50b between the modulated power supply voltage line indicating heat loss and the transmitted signal TX is very small. In other words, it can be stated that when the modulated power supply voltage V_M follows the envelope of the transmitted signal TX, the heat loss of the wireless communication device 10 is reduced and the thermal efficiency is increased.

[0053] Figure 2C It is a graph of the power supply voltage that is not synchronized with the input signal, based on a comparative example. Figure 2C The graph shows the situation when the modulated power supply voltage supplied to the power amplifier and the first RF transmitted signal TX_RF1 are out of sync. (Refer to...) Figure 1 describe Figure 2C .

[0054] Reference Figure 1 The paths of the transmit signal TX output from the modem 100 to the power amplifier 300 via the RFIC 200A and the path to the power amplifier 300 via the voltage modulator 600 are different from each other, and the phase of the modulated power supply voltage V_M input to the power amplifier 300 and the phase of the first RF transmit signal TX_RF1 may not match each other (or may be out of sync).

[0055] exist Figure 2C In the case of, with Figure 2B Compared to the example embodiment, the linearity of the power amplifier 300 may be degraded. Therefore, the wireless communication device 10 needs to delay the envelope signal ENV by an appropriate delay value so that the phase of the modulated power supply voltage V_M and the phase of the first RF transmission signal TX_RF1 match each other.

[0056] Based on the wireless communication device 10 according to the example embodiment, the controller 700 provides an optimized delay value to the delay circuit 640 such that the phase of the modulated power supply voltage V_m and the phase of the first RF transmission signal TX_RF1 can be matched with each other.

[0057] Figure 3 This is a flowchart of an envelope delay optimization method according to an example embodiment. (Refer to...) Figure 1 describe Figure 3 .

[0058] In operation S120, in test mode, the wireless communication device 10 can estimate the adjacent channel leakage ratio by applying a test input signal INPUT using multiple test delay values. For example, in test mode, the modem 100 can output a test input signal INPUT corresponding to multiple frequencies selected in the channel band. The voltage modulator 600 can output a modulated power supply voltage V_M based on the test input signal INPUT using each of the multiple test delay values. The controller 700 can estimate the adjacent channel leakage ratio based on the modulated power supply voltage V_M using a test output signal OUTPUT output from the power amplifier 300. Thus, the controller 700 can obtain multiple estimated adjacent channel leakage ratios corresponding to the multiple test delay values ​​respectively.

[0059] In operation S140, the wireless communication device 10 can select a test delay value corresponding to the largest estimated adjacent channel leakage ratio among a plurality of estimated adjacent channel leakage ratios as an optimized delay value. In normal mode, the controller 700 can provide the optimized delay value as a delay value DLY to the delay circuit 640, and the delay circuit 640 can output a delayed envelope signal ENV_D based on the delayed envelope signal ENV of the delay value DLY. The power supply 660 can output a modulated power supply voltage V_M based on the delayed envelope signal ENV_D.

[0060] Figure 4 This is a flowchart of an envelope delay optimization method according to an example embodiment. Specifically, Figure 4 It can be shown Figure 3 A flowchart of a detailed example embodiment of operation S120 is provided. Refer to... Figure 1 describe Figure 4 .

[0061] In operation S220, the wireless communication device 10 can input test input signals INPUT corresponding to a plurality of selected frequencies into a signal transmission path including a power amplifier 300. For example, as Figure 5A As shown, the test input signal INPUT can be a single-tone signal corresponding to multiple frequencies selected in the channel band. Furthermore, in the example embodiment, as... Figure 5B As shown, the test input signal INPUT can be a signal that includes a small frequency band containing multiple selected frequencies.

[0062] In operation S240, the wireless communication device 10 can convert the test output signal OUTPUT to the frequency domain. For example, the controller 700 can convert the test output signal OUTPUT output from the power amplifier 300 to the frequency domain based on the input of the test input signal INPUT. In an example embodiment, the controller 700 can convert the test output signal OUTPUT to the frequency domain by performing a Fourier transform using the test output signal OUTPUT. In an example embodiment, the controller 700 can convert the test output signal OUTPUT to the frequency domain by performing a Fast Fourier Transform (FFT) using the test output signal OUTPUT.

[0063] In operation S260, in the frequency domain, the wireless communication device 10 can estimate the adjacent channel leakage ratio based on the amplitude of the intermodulation components and the amplitudes of components corresponding to a plurality of selected frequencies. For example, in the frequency domain, the controller 700 can estimate the adjacent channel leakage ratio based on the ratio of the amplitude of the fundamental frequency component included in the test output signal OUTPUT to the amplitude of the intermodulation components. In an example embodiment, the intermodulation components may include third-order intermodulation components and / or fifth-order intermodulation components. Furthermore, in an example embodiment, when half of the sampling rate is less than three times the selected frequency, the controller 700 can estimate the adjacent channel leakage ratio based on the ratio of the amplitude of the fundamental frequency component to the amplitude of the aliased intermodulation components.

[0064] Figure 5A and Figure 5B This is a diagram illustrating the frequency characteristics of a test input signal under a test mode according to an example embodiment. Figure 5A and Figure 5B Can be shown Figure 1 An example embodiment of the test input signal INPUT. See [reference]. Figure 1 describe Figure 5A and 5B .

[0065] Reference Figure 5A The test input signal INPUT can be a single-tone signal corresponding to a plurality of frequencies selected in the channel band CB. The selected plurality of frequencies can include a first frequency and a second frequency, wherein the second frequency can be a frequency having the same value as the first frequency but different in sign. For example, the selected plurality of frequencies can include a positive first frequency +f_1 and a negative first frequency -f_1. In other words, the test input signal INPUT can be a single-tone signal having a positive first frequency +f_1 component and a negative first frequency -f_1 component. The first frequency f_1 can be equal to or less than the channel band frequency f_cb. The channel band frequency f_cb can correspond to half the bandwidth of the channel band CB, and in an example embodiment, the first frequency f_1 can be the channel band frequency f_cb.

[0066] Reference Figure 5BThe test input signal INPUT may include multiple bandwidth components corresponding to multiple frequencies selected in the channel band CB, and each of the multiple bandwidth components may include a component corresponding to the multiple frequencies and may correspond to a unit bandwidth signal generated by a resource block in the modem 100. For example, the selected multiple frequencies may include a positive first frequency +f_1 and a negative first frequency -f_1. The test input signal INPUT includes a component corresponding to the positive first frequency +f_1 and may include a bandwidth component with bandwidth df, and includes a component corresponding to the negative first frequency -f_1 and may include a bandwidth component with bandwidth df. The bandwidth df may correspond to a unit bandwidth of a resource block in the modem 100.

[0067] Figure 6 This is a diagram illustrating the frequency characteristics of the test output signal under the test mode according to an example embodiment. Specifically, Figure 6 It can be shown according to, for example Figure 5A The diagram shows the frequency response of the test output signal generated from the input test signal shown. (Refer to...) Figure 1 describe Figure 6 .

[0068] Reference Figure 5A The test input signal INPUT may include a component corresponding to a positive first frequency +f_1 and a component corresponding to a negative first frequency -f_1. In other words, the test input signal INPUT may include a component corresponding to a first frequency f_1 and a component corresponding to a second frequency f_2, where the second frequency f_2 may be a negative first frequency -f_1. The test output signal OUTPUT, output in response to the test input signal INPUT being input to a signal transmission path including RFIC200A and power amplifier 300, may include a fundamental frequency component and an intermodulation component corresponding to each of a plurality of selected frequencies. For example, the test output signal OUTPUT may include a fundamental frequency component, a third-order intermodulation component, and a fifth-order intermodulation component. The fundamental frequency component may include a component corresponding to a positive first frequency +f_1 and a component corresponding to a negative first frequency -f_1. The third-order intermodulation component may include a component corresponding to 2*f_1-f_2 and a component corresponding to 2*f_2-f_1. In the example embodiment, when f_2 equals -f_1, the third-order intermodulation component may include a component corresponding to 3*f_1 and a component corresponding to -3*f_1. The fifth-order intermodulation component may include a component corresponding to 3*f_1-2f_2 and a component corresponding to 3*f_2-2f_1. In the example embodiment, when f_2 equals -f_1, the fifth-order intermodulation component may include a component corresponding to 5*f_1 and a component corresponding to -5*f_1.

[0069] According to an example embodiment, the controller 700 can estimate the adjacent channel leakage ratio by converting the test output signal OUTPUT to the frequency domain and based on the ratio of the amplitude of the fundamental frequency component to the amplitude of the intermodulation component.

[0070] Figure 6 The frequency characteristics of the test output signal OUTPUT are shown when the half-sampling frequency corresponding to half the sampling rate of the wireless communication device 10 is greater than 3 and 5 times the selected frequency (e.g., the first frequency f_1). When the half-sampling frequency is less than three times the first frequency f_1, the intermodulation components of the test output signal OUTPUT may be aliased. The following will refer to... Figure 7 A more detailed description of the intermodulation components of aliasing.

[0071] Figure 7 This is a diagram illustrating the frequency characteristics of the test output signal under the test mode according to an example embodiment. Specifically, Figure 7 It can be shown that in the wireless communication device 10 supporting a finite sampling rate (SR), according to... Figure 5A The frequency characteristics of the test output signal generated from the input of the test input signal INPUT are shown. Specifically, with... Figure 6 compared to, Figure 7 The example shows the case where the half-sampling frequency f_hsr corresponding to half of the sampling rate SR is greater than the first frequency f_1 but less than 3 times the first frequency f_1.

[0072] Because the first frequency f_1 corresponding to the fundamental frequency component of the test output signal OUTPUT is less than the half-sampling frequency f_hsr, the test output signal OUTPUT can have fundamental frequency components corresponding to the positive first frequency +f_1 and the negative first frequency -f_1 without shifting its position in the frequency domain.

[0073] Furthermore, because the frequency corresponding to the third-order intermodulation component of the test output signal OUTPUT is greater than the half-sampling frequency f_hsr, the third-order intermodulation component is downsampled, and the component corresponding to the third-order intermodulation component can appear at the third-order aliasing frequency f_a3. The component appearing at the third-order aliasing frequency f_a3 will be called the aliased third-order intermodulation component. The relationship between the third-order aliasing frequency f_a3 and the first frequency f_1 can be shown in Equation 1 below.

[0074] Equation 1

[0075] f_a3=3*f_1-f_hsr*[3*f_1 / f_hsr]

[0076] In Equation 1, the symbol "[]" represents the Gaussian function, and is a function of the largest integer among the integers whose output is not greater than the input value. As a non-limiting example for ease of description, when the first frequency f_1 is 50MHz and the sampling rate SR is 122.88MHz, the Gaussian function can be 2, and can be obtained by multiplying 3 by 50MHz and dividing by 61.44MHz, where the value obtained by multiplying 3 by 50MHz and dividing by 61.44MHz is 2.44. The largest integer among the integers not greater than 2.44 is 2. Therefore, the third aliasing frequency f_a3 can be 27.12MHz, obtained by subtracting the value obtained by multiplying 2 by 61.44MHz from 150MHz.

[0077] Similarly, because the frequency corresponding to the fifth-order intermodulation component of the test output signal OUTPUT is greater than the half-sampling frequency f_hsr, the fifth-order intermodulation component is downsampled, and the component corresponding to the fifth-order intermodulation component can appear at the fifth-order aliasing frequency f_a5. The component appearing at the fifth-order aliasing frequency f_a5 will be called the aliased fifth-order intermodulation component. The relationship between the fifth-order aliasing frequency f_a5 and the first frequency f_1 can be shown in Equation 2 below.

[0078] Equation 2

[0079] f_a5=5*f_1-f_hsr*[5*f_1 / f_hsr]

[0080] In Equation 2, [] is the Gaussian function, and is a function of the largest integer among the integers whose output is not greater than the input value. As a non-restrictive example for ease of description, when the first frequency f_1 is 50MHz and the sampling rate SR is 122.88MHz, the Gaussian function can be 4, and can be obtained by multiplying 5 by 50MHz and dividing by 61.44MHz, where the value obtained by multiplying 5 by 50MHz and dividing by 61.44MHz is 4.06. The largest integer among the integers not greater than 4.06 is 4. Therefore, the fifth-order aliasing frequency f_a5 can be 4.24MHz obtained by subtracting the value obtained by multiplying 4 by 61.44MHz from 250MHz. As a non-limiting example for ease of description, when the first frequency f_1 is 40MHz and the sampling rate SR is 122.88MHz (i.e., when the half-sampling frequency f_hsr is 61.44MHz), the fifth-order aliasing frequency f_a5 can be 15.68MHz obtained by subtracting the value obtained by multiplying 3 by 61.44MHz from 200MHz.

[0081] Figure 8 This is a diagram illustrating a controller 700 according to an example embodiment. The controller 700 can be connected to... Figure 1 The controller 700 corresponds accordingly. (See reference...) Figure 1describe Figure 8 .

[0082] The controller 700 may include adjacent channel leakage ratio (ACLR) estimation circuitry 720 and optimized delay value selection circuitry 740.

[0083] In test mode, the ACLR estimation circuit 720 can estimate the adjacent channel leakage ratio based on the test output signal OUTPUT according to the test delay value, and can generate the estimated adjacent channel leakage ratio ACLR_E. For example, the ACLR estimation circuit 720 can convert the test output signal OUTPUT to the frequency domain, and can obtain multiple aliasing frequencies f_a based on the sampling rate SR and multiple selected frequencies f_sel. Based on the converted test output signal OUTPUT_f, the ACLR estimation circuit 720 can obtain the estimated adjacent channel leakage ratio ACLR_E based on the amplitude of the components corresponding to the multiple selected frequencies f_sel and the amplitude of the components corresponding to the multiple aliasing frequencies f_a.

[0084] Therefore, the ACLR estimation circuit 720 may include an aliasing frequency calculation circuit 722, a conversion circuit 724, and a calculation circuit 726.

[0085] The aliasing frequency calculation circuit 722 can obtain multiple aliasing frequencies f_a based on the sampling rate SR and multiple selected frequencies f_sel within the channel band. For example, the aliasing frequency calculation circuit 722 can obtain third-order aliasing frequencies and / or fifth-order aliasing frequencies in the same manner as Equations 1 and 2. The aliasing frequency calculation circuit 722 can provide the selected multiple frequencies f_sel and multiple aliasing frequencies f_a to the calculation circuit 726.

[0086] The transformation circuit 724 outputs a transformed test output signal OUTPUT_f by transforming the test output signal OUTPUT to the frequency domain. The transformation circuit 724 can sample the test output signal OUTPUT at a sampling rate SR. For example, the transformation circuit 724 can use a Fourier transform to transform the test output signal OUTPUT, and in an example embodiment, the transformation circuit 724 can use a Fast Fourier Transform.

[0087] The calculation circuit 726 can obtain an estimated adjacent channel leakage ratio ACLR_E based on the amplitudes of the components corresponding to the selected plurality of frequencies f_sel and the amplitudes of the components corresponding to the plurality of aliasing frequencies f_a included in the converted test output signal OUTPUT_f. For example, the calculation circuit 726 can obtain the estimated adjacent channel leakage ratio ACLR_E by dividing the amplitude of the components corresponding to the selected plurality of frequencies f_sel and the amplitude of the components corresponding to the plurality of aliasing frequencies f_a included in the converted test output signal OUTPUT_f. The calculation circuit 726 can provide the estimated adjacent channel leakage ratio ACLR_E to the optimized delay value selection circuit 740.

[0088] The optimized delay value selection circuit 740 can accumulate multiple estimated adjacent channel leakage ratios corresponding to multiple test delay values. The optimized delay value selection circuit 740 can select the test delay value corresponding to the largest adjacent channel leakage ratio among the estimated multiple adjacent channel leakage ratios as the optimized delay value DLY_OP. In normal mode, the controller 700 can provide the optimized delay value DLY_OP to the delay circuit 640.

[0089] Figure 9 This is a flowchart of an envelope delay optimization method according to an example embodiment. Specifically, Figure 9 Can be shown Figure 4 Detailed flowchart of S260 operation. (Refer to...) Figure 1 and Figure 8 describe Figure 9 .

[0090] In operation S320, controller 700 can obtain multiple aliasing frequencies f_a based on selected multiple frequencies f_sel and sampling rate SR. Multiple aliasing frequencies f_a can be obtained with reference to Equations 1 and 2, and further details can be found below. Figure 10 Obtain multiple aliasing frequencies f_a.

[0091] In operation S340, controller 700 can obtain an estimated adjacent channel leakage ratio ACLR_E based on the amplitude of the components corresponding to the selected multiple frequencies f_sel and the amplitude of the components corresponding to the aliased intermodulation components.

[0092] Figure 10 This is a flowchart of an envelope delay optimization method according to an example embodiment. Specifically, Figure 10 Can be shown Figure 9 A detailed flowchart of the S320 operation. In other words, Figure 10 This could be a flowchart of a method for obtaining the aliasing frequency based on Equations 1 and 2. (Refer to...) Figure 1 and Figure 8 describe Figure 10 .

[0093] In operation S420, controller 700 can obtain the multiplication result by multiplying the selected frequencies by the intermodulation order. For example, when obtaining the aliasing frequency corresponding to the third-order intermodulation component, controller 700 can multiply the selected frequency by 3, and when obtaining the aliasing frequency corresponding to the fifth-order intermodulation component, controller 700 can multiply the selected frequency by 5.

[0094] In operation S440, controller 700 may divide the multiplication result by half of the sampling rate SR. For example, controller 700 may divide the multiplication result of operation S420 by the half-sampling frequency f_hsr corresponding to half of the sampling rate SR.

[0095] In operation S460, controller 700 can apply a Gaussian function to the division result. For example, controller 700 can obtain a Gaussian function value by applying the Gaussian function to the division result in operation S440.

[0096] In operation S480, controller 700 can subtract the value obtained by multiplying the Gaussian function value by half the sampling rate SR from the multiplication result in operation S420. For example, controller 700 can obtain the aliasing frequency by subtracting the value obtained by multiplying the Gaussian function value in operation S460 by the half-sampling frequency f_hsr from the multiplication result in operation S420.

[0097] Figure 11A and Figure 11B This is a flowchart of an envelope delay optimization method according to an example embodiment. Specifically, Figure 11A and 11B Can be shown Figure 9 Detailed flowchart of S320 operation. (Refer to...) Figure 1 and Figure 8 describe Figure 11A and Figure 11B .

[0098] For ease of explanation, assume that the test input signal INPUT is a single-tone signal corresponding to a first frequency and a second frequency. In the example embodiment, the second frequency may correspond to a negative of the first frequency.

[0099] The test output signal OUTPUT may include a first fundamental frequency component corresponding to a first frequency and an intermodulation component corresponding to the first frequency. In an example embodiment, the intermodulation component corresponding to the first frequency may be aliased due to sampling rate limitations. Furthermore, the test output signal OUTPUT may include a second fundamental frequency component corresponding to a second frequency and an intermodulation component corresponding to the second frequency. In an example embodiment, the intermodulation component corresponding to the second frequency may be aliased due to sampling rate limitations.

[0100] Reference Figure 11AIn operation S520, the controller 700 can obtain a first ratio based on the amplitude of the first fundamental frequency component and the amplitude of the first aliasing intermodulation component. For example, the controller 700 can obtain the first ratio by dividing the amplitude of the first fundamental frequency component by the amplitude of the first aliasing intermodulation component.

[0101] In operation S540, the controller 700 can obtain a second ratio based on the amplitude of the second fundamental frequency component and the amplitude of the second aliasing intermodulation component. For example, the controller 700 can obtain the second ratio by dividing the amplitude of the second fundamental frequency component by the amplitude of the second aliasing intermodulation component.

[0102] In operation S560, controller 700 may obtain an estimated adjacent channel leakage ratio ACLR_E based on a first ratio and a second ratio. In an example embodiment, controller 700 may obtain the estimated adjacent channel leakage ratio ACLR_E by averaging the first ratio and the second ratio. Optionally, in an example embodiment, controller 700 may select the smaller of the first ratio and the second ratio as the estimated adjacent channel leakage ratio ACLR_E.

[0103] Reference Figure 11B In operation S510, the controller 700 can obtain the first average value by averaging the amplitude of the first fundamental frequency component and the amplitude of the second fundamental frequency component.

[0104] In operation S530, the controller 700 can obtain a second average value by averaging the amplitudes of the first aliasing intermodulation component and the amplitudes of the second aliasing intermodulation component.

[0105] In operation S550, controller 700 can obtain an estimated adjacent channel leakage ratio ACLR_E based on a first average and a second average. For example, controller 700 can obtain the estimated adjacent channel leakage ratio ACLR_E by dividing the first average by the second average.

[0106] Figure 12A and Figure 12B This is a diagram illustrating the frequency characteristics of a test input signal under a test mode according to an example embodiment. Figure 12A and Figure 12B Show Figure 1 An example of the test input signal INPUT. See [reference]. Figure 1 describe Figure 12A and Figure 12B .

[0107] Reference Figure 12AThe test input signal INPUT can be a single-tone signal corresponding to a plurality of selected frequencies in the channel band CB. For example, the selected frequencies may include a positive first frequency +f_1, a negative first frequency -f_1, a positive second frequency +f_2, and a negative second frequency -f_2. In other words, the test input signal INPUT can be a single-tone signal having a positive first frequency +f_1 component, a negative first frequency -f_1 component, a positive second frequency +f_2 component, and a negative second frequency -f_2 component. The first frequency f_1 and the second frequency f_2 may be equal to or less than the channel band frequency f_cb. The channel band frequency f_cb may correspond to half the bandwidth of the channel band CB, and in an example embodiment, the second frequency f_2 may be the channel band frequency f_cb.

[0108] Reference Figure 12B The test input signal INPUT may include multiple bandwidth components corresponding to multiple selected frequencies in the channel band CB, and each of the multiple bandwidth components may include a component corresponding to multiple frequencies and may correspond to a unit bandwidth signal generated by a resource block in the modem 100. For example, the selected multiple frequencies may include a positive first frequency +f_1, a negative first frequency -f_1, a positive third frequency +f_3, and a negative third frequency -f_3. The test input signal INPUT includes a component corresponding to the positive first frequency +f-1 and may include a bandwidth component with bandwidth df, includes a component corresponding to the negative first frequency -f-1 and may include a bandwidth component with bandwidth df, includes a component corresponding to the positive third frequency +f-3 and may include a bandwidth component with bandwidth df, and includes a component corresponding to the negative third frequency -f-3 and may include a bandwidth component with bandwidth df. The bandwidth df may correspond to a unit bandwidth of a resource block in the modem 100.

[0109] Figure 13 This is a diagram illustrating the frequency characteristics of the test output signal under a test mode according to an example embodiment. It will be based on... Figure 7 To describe the differences Figure 13 . Reference Figure 1 describe Figure 13 .

[0110] Specifically, Figure 13 The frequency characteristics of the test output signal OUTPUT can be shown when the half-sampling frequency f_hsr is less than the first frequency selected as the frequency.

[0111] In such Figure 13In the example embodiment shown, the controller 700 can obtain an estimated adjacent channel leakage ratio based on the frequency component corresponding to the first aliasing frequency f_a1 (where the selected frequency is the downsampled frequency) and the aliased intermodulation component (not the component corresponding to the selected frequency).

[0112] Figure 14 This is a diagram of a wireless communication device 1000 according to an example embodiment. Figure 14 As shown, the wireless communication device 1000 may include an application-specific integrated circuit (ASIC) 1100, an application-specific instruction set processor (ASIP) 1300, a memory 1500, a main processor 1700, and a main memory 1900. At least two of the ASIC 1100, ASIP 1300, and main processor 1700 can communicate with each other. Furthermore, at least two of the ASIC 1100, ASIP 1300, memory 1500, main processor 1700, and main memory 1900 may be included in a single chip.

[0113] ASIP 3300 is an application-specific integrated circuit that supports a dedicated instruction set for that application and can execute instructions included in that instruction set. Memory 1500 can communicate with ASIP 1300 and can store multiple instructions executed by ASIP 1300 as a non-transitory storage device. For example, as a non-limiting example, memory 3500 may include any type of memory accessible by ASIP 1300, such as random access memory (RAM), read-only memory (ROM), magnetic tape, magnetic disk, optical disk, volatile memory, non-volatile memory, and combinations thereof.

[0114] The main processor 1700 can control the wireless communication device 1000 by executing multiple instructions. For example, the main processor 1700 can control the ASIC 1100 and ASIP 1300, and can process data received through the MIMO channel or user input to the wireless communication device 1000. The main memory 1900 can communicate with the main processor 1700 and can store multiple instructions executed by the main processor 1700 as a non-transitory storage device. For example, the main memory 1900 can include any type of memory accessible by the main processor 1700, such as RAM, ROM, magnetic tape, magnetic disk, optical disk, volatile memory, non-volatile memory, and combinations thereof, as non-limiting examples.

[0115] The method for optimizing the delay value of the envelope signal and the method for operating a power amplifier based on the modulated power supply voltage according to the above example embodiments can be comprised of methods including... Figure 14The operation is performed by at least one component of the wireless communication device 1000. In some example embodiments, at least one of the methods for optimizing the delay value of the envelope signal and operating the power amplifier based on the modulated power supply voltage can be implemented as a plurality of instructions stored in the memory 1500. In some example embodiments, the ASIP 1300 executes the plurality of instructions stored in the memory 1500 to perform at least one operation of the methods.

[0116] Although exemplary embodiments have been specifically shown and described, it will be understood that various changes in form and detail may be made therein without departing from the spirit and scope of the claims.

Claims

1. A method for optimizing the delay value of an envelope, the method comprising: In test mode, multiple adjacent channel leakage ratios corresponding to multiple test delay values ​​are estimated based on the test output signal output from the power amplifier, wherein the test output signal is generated by the power amplifier based on test input signals corresponding to multiple frequencies; Select the test delay value corresponding to the maximum value among the estimated adjacent channel leakage ratios; and In normal mode, the power supply voltage is supplied to the power amplifier based on the envelope signal that has been delayed according to the selected test delay value. The step of estimating the plurality of adjacent channel leakage ratios includes: for each of the plurality of test delay values, estimating the corresponding adjacent channel leakage ratio based on the ratio of the amplitude of the frequency-corresponding component included in the test output signal to the amplitude of the intermodulation component of the test output signal.

2. The method as described in claim 1, wherein, The steps for estimating the leakage ratio of the plurality of adjacent channels include: For each of the plurality of test delay values, a test input signal is provided to a signal transmission path including a power amplifier; and The envelope signal of the test input signal is delayed based on the corresponding test delay value among the plurality of test delay values, thereby providing a modulated power supply voltage to the power amplifier.

3. The method as described in claim 1, wherein, The test input signal includes single-tone signals corresponding to the plurality of frequencies.

4. The method of claim 1, wherein, The test input signal includes multiple frequency band components, and Each of the plurality of frequency band components includes a component corresponding to the plurality of frequencies and a component of a unit frequency band generated by a resource block.

5. The method of claim 1, wherein, The intermodulation components include any one or any combination of third-order and fifth-order intermodulation components from components corresponding to the plurality of frequencies included in the test input signal.

6. The method of claim 1, wherein, The half-sampling frequency corresponding to half the sampling rate is less than three times the first frequency included among the plurality of frequencies, and The step of estimating the leakage ratio of the plurality of adjacent channels includes estimating the corresponding adjacent channel leakage ratio based on the amplitude of the component corresponding to one of the plurality of frequencies included in the test output signal and the amplitude of the aliased third-order intermodulation component.

7. The method of claim 6, wherein, The step of estimating the leakage ratio of the plurality of adjacent channels further includes: For each of the plurality of test delay values, the test output signal is converted to the frequency domain; The first aliasing frequency is obtained based on the half-sampling frequency and the first frequency; and The step of estimating the corresponding adjacent channel leakage ratio based on the amplitude of the component corresponding to one of the plurality of frequencies included in the test output signal and the amplitude of the aliased third-order intermodulation component includes: estimating the plurality of adjacent channel leakage ratios based on the corresponding ratio of the amplitude of the component corresponding to a first frequency and the amplitude of the component corresponding to a first aliasing frequency included in the test output signal.

8. The method of claim 7, wherein, The steps to convert the test output signal to the frequency domain include: performing a fast Fourier transform using the test output signal.

9. The method of claim 7, wherein, The steps to obtain the first aliasing frequency include: Multiply the first frequency by the intermodulation order to obtain the multiplication result; Divide the multiplication result by half the sampling frequency to obtain the division result; The Gaussian function is applied to the division result to obtain the Gaussian function value; and The first aliasing frequency is obtained by subtracting the value obtained by multiplying the Gaussian function value by the half-sampling frequency from the multiplication result.

10. The method of claim 1, wherein, The plurality of frequencies includes a first frequency and a second frequency, and The step of estimating the leakage ratio of the plurality of adjacent channels includes: The first ratio is obtained based on the amplitude of the component corresponding to the first frequency included in the test output signal and the amplitude of the first aliasing intermodulation component. The second ratio is obtained based on the amplitude of the component corresponding to the second frequency included in the test output signal and the amplitude of the second aliasing intermodulation component; and The test delay value is selected based on the first ratio and the second ratio.

11. The method of claim 1, wherein, The plurality of frequencies includes a first frequency and a second frequency, and The step of estimating the leakage ratio of the plurality of adjacent channels includes: The first average value is obtained by averaging the amplitudes of the components corresponding to the first frequency and the amplitudes of the components corresponding to the second frequency included in the test output signal. The second average value is obtained by averaging the amplitudes of the first aliasing intermodulation component and the amplitudes of the second aliasing intermodulation component; and The leakage ratio of the multiple adjacent channels is estimated based on the first average and the second average.

12. A communication device, comprising: The modem is configured to generate single-tone signals corresponding to multiple selected frequencies as test input signals in test mode. The power amplifier is configured to generate a test output signal based on the test input signal transmitted via the signal transmission path; A voltage modulator is configured to: in test mode, sequentially generate a delayed envelope signal based on each of a plurality of test delay values, and sequentially supply power voltage to a power amplifier based on the delayed envelope signal; as well as The controller is configured to: in test mode, for each of the plurality of test delay values, estimate the adjacent channel leakage ratio based on the amplitude of the component corresponding to the selected plurality of frequencies and the amplitude of the intermodulation component included in the test output signal, select the test delay value corresponding to the maximum value of the estimated plurality of adjacent channel leakage ratios, and control the voltage modulator based on the test delay value in normal mode.

13. The communication device as claimed in claim 12, wherein, The half-sampling frequency corresponding to the sampling rate of the power amplifier is less than three times the first frequency included in the selected plurality of frequencies, and The controller is further configured to estimate the adjacent channel leakage ratio based on the amplitudes of the components corresponding to the selected plurality of frequencies included in the test output signal and the amplitudes of the aliased third-order intermodulation components.

14. The communication device as claimed in claim 12, wherein, The controller is configured to: convert the test output signal to the frequency domain, obtain a plurality of aliasing frequencies based on a half-sampling frequency corresponding to the sampling rate of the power amplifier and the selected plurality of frequencies, and estimate the adjacent channel leakage ratio based on the ratio of the amplitude of the component corresponding to the selected plurality of frequencies included in the test output signal to the amplitude of the component corresponding to the plurality of aliasing frequencies.

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