KR20110057630A - Rf receiver, transmitter and transceiver for 3g lte mobile communication system using zero-if - Google Patents

Abstract

PURPOSE: An RF receiver of a 3G LTE mobile communication system, transmitter, and transceiver which uses direct conversion are provided to convert a high frequency carrier band signal in order not to pass through a intermediate frequency band. CONSTITUTION: An I/Q demodulator(333) demodulates an output signal of a band pass filter into I/Q(In-phase/Quadrature-phase). Reception end gain amplifiers control the gain of the output signal of the I/O demodulator. A low pass filter(336) selectively passes through the band of a predetermined channel. Reception end differential amplifiers amplify the band of the predetermined channel.

Description

RF Receiver, Transmitter and Transceiver for 3G LTE Mobile Communication System Using Zero-IF in 3G LTE Mobile Communication System Using Direct Conversion Method

The present invention relates to an RF receiver, a transmitter and a transmission / reception apparatus of a 3G LTE mobile communication system using a direct conversion scheme (Zero-IF). Specifically, the present invention provides a direct conversion scheme (Zero-IF) for converting a high frequency carrier band (RF) signal and a low frequency baseband signal without passing through an intermediate low frequency band (IF). The present invention relates to an RF receiver, a transmitter, and a transmission / reception device applied to a system.

The present invention is derived from the research conducted as part of the IT growth engine technology development project of the Ministry of Knowledge Economy [Task management number: 2006-S-001-04, Task name: Development of adaptive wireless access and transmission technology for 4G mobile communication] .

3G Long Term Evolution (LTE) mobile communication system is a system after Rel. 6 of WCDMA series 3G LTE mobile communication system including CDMA2000 and HSDPA which are currently used, and uses frequency and high speed multimedia service more efficiently than existing system. It means a mobile communication system that is evolved into an IP network.

The 3G LTE mobile communication system is suitable for efficient packet data transmission, optimizes multimedia services such as broadcasting services, and provides 3GPP standards in September 2007 to provide efficient use of frequency resources, mobility, and quality of service. It is finished. 3G LTE aims at a transmission rate of 100Mbps for downlink and 50Mbps for uplink based on a 20MHz bandwidth. 2x to 4x increase in frequency efficiency (5bps / Hz), support for a wide range of bandwidths from 1.25MHz to 20MHz, improved data rates at cell boundaries, optimized for low speed mobile stations, and support for 350km / h high speed mobile stations. Wireless transmission technology for. In addition, it is a technology that aims to support various services based on price competitive system, low latency, and packet data transmission.

The 3G LTE mobile communication terminal supports data rates of downlink 30 Mbps and uplink 15 Mbps at a moving speed of 120 km / h based on a bandwidth of 20 MHz. In addition, the terminal provides a high-quality and high-speed multimedia service as a terminal of a 3G LTE mobile communication system in which mobile video services are provided in earnest as opposed to 3.5 generation HSDPA.

In the conventional 3G LTE mobile communication system, as in other mobile communication systems, a superheterodyne using an intermediate low frequency band (IF) for interconversion between a high frequency carrier band (RF) signal and a low frequency baseband signal. The superheterodyne method has been widely used.

1 illustrates a frequency conversion process of a conventional superheterodyne method.

This method converts the signal into a three-level structure such as a low frequency baseband 101, an intermediate low frequency band (IF) 102, and a high frequency carrier band (RF) 103. In the case of transmission, the digital signal of the low frequency baseband 101, which directly handles information such as audio, video, and data, is up-converted into an analog signal of the intermediate low frequency band 102, and then a high frequency carrier wave band ( Amplified and upconverted back to the analog signal of 103), the antenna radiates electromagnetic waves. In the case of reception, on the contrary, the analog signal of the high frequency carrier band 103 received by the antenna by electromagnetic waves is converted into the analog signal of the intermediate low frequency band 102 after the noise removing and amplifying process, and then the low frequency baseband ( Down-converted back to the digital signal of 101).

As described above, in the conventional superheterodyne scheme, when the low frequency baseband 101 signal is transmitted or received by the RF carrier 103, each of them is converted into the intermediate low frequency band (IF) 102, respectively. . When the intermediate low frequency (IF) 102 is used, frequency conversion must be added several times, so that an imaginary frequency occurs after passing a mixer in a transmitter and a receiver. If the imaginary frequency of the transmitting end is generated, the problem of removing unwanted spurious components is complicated, and the receiving imaginary frequency can be a very fatal problem of directly disturbing the intermediate low frequency (IF) 102. The superheterodyne method has a problem in that a lot of noise signals are generated due to frequency conversion which is repeated in performance.

In order to solve this problem, an additional mixer may be added. Since a filter must be attached every time the mixer is added, various filters, amplifiers, and peripherals, including SAW filters, which are used only by the intermediate low frequency band (IF) 102 There is a problem that the cost of the communication system is increased due to the circuits.

In order to solve the above problems, an object of the present invention is to apply a direct conversion scheme (Zero-IF) to the 3G LTE mobile communication device to perform a mutual conversion with a high frequency carrier band signal without passing through an intermediate frequency band (IF).

In addition, an object of the present invention is to provide a 3G LTE mobile communication device capable of low power amplification and low interference transmission and reception using a direct conversion scheme (Zero-IF).

In addition, an object of the present invention is to realize system simplification and cost reduction by reducing the use of expensive components such as SAW filter or up / down mixer in 3G LTE mobile communication devices.

In order to achieve the above object, a first aspect of the present invention provides a band pass filter for selectively passing a predetermined frequency band among received signals, and converts a carrier band signal to a downlink frequency using a direct conversion scheme (Zero-IF). A downlink local oscillator for generating a downlink local oscillation signal, and an I / Q (in-phase / quadrature-phase) demodulated output signal of the bandpass filter by using the downlink local oscillation signal; An I / Q demodulator divided into four channels of Q-, a receiver gain amplifier for adjusting the gain of the output signal of the I / Q demodulator to stabilize the power, and a band of a predetermined channel among the output signals of the receiver gain amplifier And a receiver differential amplifier for amplifying a band of the predetermined channel among the output signals of the low pass filter and selectively dividing the signal into four channels. It provides an RF receiver of a 3G LTE mobile communication system using the converting mode (Zero-IF).

In addition, the receiver gain amplifier and the receiver differential amplifier are configured in plural in accordance with the I channel and the Q channel, respectively, to process the received signals of the corresponding channels, and the downlink frequency is 2.67 GHz to 2.69 GHz. An RF receiver of a 3G LTE mobile communication system using IF) is provided.

An antenna for receiving an electromagnetic wave signal in the air and converting the signal into an electrical signal, a reception frequency bandpass filter for selectively passing a band corresponding to the downlink frequency among the output signals of the antenna, and an output of the reception frequency bandpass filter It provides an RF receiver of a 3G LTE mobile communication system using a direct conversion method (Zero-IF) further comprising a low noise amplifier for amplifying a signal while suppressing noise and outputting the signal to the band pass filter.

In order to achieve the above object, a second aspect of the present invention provides a first stage differential amplifier for amplifying the four channel bands of a transmission signal input to four channels of I +, I-, Q +, and Q-, and An LC filter for selectively passing a band of a channel being used among the output signals of the primary amplifier, a second differential amplifier for amplifying the baseband signal of the LC filter and dividing the signal into four channels, and a direct conversion method ( An uplink local oscillator for generating an uplink local oscillation signal for converting the baseband signal into an uplink frequency using zero-IF), and outputting the output signal of the second differential amplifier of the transmitter using the uplink local oscillation signal. (In-phase / Quadrature-phase) Direct conversion including an I / Q modulator for modulation and integration into one channel, and a transmitter gain amplifier for adjusting and amplifying the gain of the output signal of the I / Q modulator to stabilize the power.The present invention provides an RF transmitter of a 3G LTE mobile communication system using Zero-IF.

In addition, the transmitter differential amplifier is composed of a plurality of channels according to the I and Q channels to process the transmission signal of the corresponding channel, the uplink frequency is 3G LTE using a direct conversion scheme (Zero-IF) is 2.53GHz to 2.55GHz An RF transmitter of a mobile communication system is provided.

In addition, a high power amplifier for amplifying the power of the output signal of the transmitter gain amplifier, a transmission frequency bandpass filter for selectively passing the band corresponding to the uplink frequency of the output signal of the high power amplifier, and the transmission frequency bandpass filter Provides an RF transmitter of the 3G LTE mobile communication system using a direct conversion method (Zero-IF) further comprises an antenna for converting the output signal of the electromagnetic wave to radiate into the atmosphere.

In order to achieve the above object, a third aspect of the present invention provides an I / Q (In-phase / Quadrature-phase) demodulation of a carrier band received signal by a direct conversion method (Zero-IF), and thus I +, I-, Q +, and Q. A receiver for outputting four channels of baseband received signals separated by-, and four channels of baseband transmission signals divided into I +, I-, Q +, and Q- by the direct conversion method (Zero-IF). (In-phase / Quadrature-phase) includes a transmitter for modulating and outputting a carrier band transmission signal of one channel, and the preposition includes an antenna for transmitting and receiving an electrical signal through electromagnetic waves, the transmitter and the receiver receiving the signal. 3G LTE mobile communication system using a direct-conversion method (Zero-IF) comprising a preposition having a duplex for dividing the reception of the carrier band reception signal and the transmission of the carrier band transmission signal to share an antenna Provides an RF transceiver.

The duplex may further include a reception frequency bandpass filter for selectively passing a band corresponding to a downlink frequency among the reception electrical signals received from the antenna, and a band corresponding to an uplink frequency of the transmission electrical signals received from the transmitter. Provided is an RF transceiver of a 3G LTE mobile communication system using a direct conversion method (Zero-IF) further comprising a transmission frequency bandpass filter to pass through.

The pre-transformer may further include a low noise amplifier for amplifying the output signal of the reception frequency bandpass filter while suppressing noise, and a high power amplifier for amplifying the power of the output signal of the transmitter (Zero-IF). Provides a terminal device of the 3G LTE mobile communication system using.

The receiver is an RF receiver of a 3G LTE mobile communication system using the direct conversion scheme (Zero-IF) according to claim 1 or 2, and the transmitter is a direct conversion scheme according to claim 4 or 5. An RF transceiver of a 3G LTE mobile communication system using a direct conversion method (Zero-IF), which is an RF transmitter of a 3G LTE mobile communication system using Zero-IF), is provided.

According to the present invention, the system structure of the 3G LTE mobile communication device is simplified through a direct conversion scheme (Zero-IF).

In addition, since the intermediate low frequency band (IF) is not used, it is possible to reduce the use of SAW filters, up / down mixers, and the like in a mobile communication device.

In addition, there is an effect that the one-chip (3), light weight and cost reduction of the 3G LTE mobile communication device is possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

Figure 2 shows the frequency conversion process of the direct conversion (Zero-IF) method used in the present invention.

Zero-IF refers to a direct conversion method in which the intermediate low frequency band IF is 0 Hz, that is, no intermediate low frequency band IF is used. This is in contrast to the superheterodyne approach described above. In the direct conversion scheme, the high frequency carrier (RF) 202 is pulled up or down to the low frequency baseband 201 without using an intermediate frequency IF. Zero-IF eliminates the use of intermediate low frequency bands (IFs), which reduces the use of SAW filters and up / down mixers, simplifying the system structure and thereby reducing It suggests the possibility of one-chip, light weight, and cost reduction.

3 is a block diagram showing a schematic configuration of an RF transceiver of a 3G LTE mobile communication system using a direct conversion scheme (Zero-IF) according to an embodiment of the present invention. The RF transceiver of the present embodiment is largely composed of a transmitter 310, an anterior unit 320, and a receiver 330, and separate local oscillators are included in the transmitter 310 and the receiver 330, respectively.

The transmitter 310 performs I / Q modulation and frequency conversion on the input baseband signal using a direct conversion method, and adjusts the transmission output power to transmit the pre-transition part 320. The transmitter 310 transmits first stage differential amplifiers 311 and 312, an LC filter 313, second stage differential amplifiers 314 and 315, an uplink local oscillator 316, an I / Q modulator 317, and a transmitter gain. And an amplifier 318.

The transmitter first differential amplifiers 311 and 312 amplify the baseband analog transmission signals I +, I−, Q +, and Q− and send them to the LC filter 313. Transmitter first differential amplifiers 311 and 312 are I-channels for the baseband I + channel signals and I-channel signals. Transmitter first differential amplifiers 311 and Q-channels for the baseband Q + channel signals and Q-channel signals. The transmitting end first differential amplifier 312 may be configured separately.

The LC filter 313 selectively passes the band of the channel being used among the output signals of the first stage differential amplifiers 311 and 312 and sends the same to the second stage differential amplifiers 314 and 315.

The second differential amplifiers 314 and 315 transmit baseband analog transmission signals I +, I-, Q +, and Q- formed by amplifying the output signal of the LC filter 313 to the I / Q modulator 317. .

The uplink local oscillator 316 converts the baseband analog transmission signal output from the transmitter second differential amplifiers 314 and 315 to an uplink frequency (2.53GHz to 2.55GHz) using a direct conversion method and performs I / Q modulation. Provide uplink local oscillation signal.

The I / Q modulator 317 performs I / Q modulation on the output signals of the second stage differential amplifiers 314 and 315 using the uplink local oscillation signal, integrates them into one channel, and sends them to the transmitter gain amplifier 318.

The transmitter gain amplifier 318 adjusts and amplifies the gain of the output signal of the I / Q modulator 317 to stabilize the power and sends the gain to the high power amplifier 322 in the preposition 320. Through this process, the power of the input signal of the high power amplifier 322 is maintained above a certain level, so that the lack of gain of the high power amplifier 322 is solved, and sufficient input power can be supplied to the high power amplifier 322. .

The preposition unit 320 amplifies the RF transmission signal input from the transmission unit 310 by high power to radiate it through the antenna 321, or amplifies the RF reception signal received from the antenna 321 to the reception unit 330, or Provides a transmission / reception separation function of a frequency division duplexing scheme in which the transmitter 310 and the receiver 330 share the antenna 321 through the division of the transmission frequency and the reception frequency. Preposition 320 includes an antenna 321, a high power amplifier 322, a duplex 323, a low noise amplifier 326.

The antenna 321 radiates the transmission signal electrically transmitted from the transmitter 310 on the conductive wire to the electromagnetic wave RF in the air, or receives the electromagnetic wave RF in the air and transmits it as an electrical change of the received signal on the wire. do.

The high power amplifier 322 amplifies the power received from the transmitter 310 so as to transmit a signal having sufficient power from the duplex 323 to the antenna 321, which is the final stage, and passes the transmission frequency band in the duplex 323. Pass to filter 324.

The duplex 323 is directly connected to the antenna 321 and may include a transmission frequency band pass filter 324 and a reception frequency band pass filter 325 therein. The transmission frequency bandpass filter 324 in the duplex 323 selectively passes only the transmission frequency band (2.53 GHz to 2.55 GHz) and transmits it to the antenna 321. The reception frequency bandpass filter 325 in the duplex 323 selectively passes only the reception frequency band (2.67GHz ~ 2.69GHz) and transfers it to the low noise amplifier 326. The duplex 323 is provided with an antenna 321 in the middle of the transmission frequency band pass filter 324 and the reception frequency band pass filter 325, and the signal of the transmitter 310 and the receiver 330 by one antenna 321. It performs a function of branching, through this configuration, the transmitter 310 and the receiver 330 can effectively share a single antenna 321.

The low noise amplifier 326 amplifies the received signal received from the reception frequency bandpass filter 325 in the duplex 323 while suppressing noise and transferring the received signal to the receiver 330.

The receiving unit 330 converts the frequency of the RF receiving signal applied from the preposition unit 320 into a baseband analog receiving signal, performs I / Q demodulation, and receives a reception gain to stabilize the power change of the signal input from the preposition unit 320. Function to control. The receiver 330 includes a band pass filter 331, a downlink local oscillator 332, an I / Q demodulator 333, a receiver gain amplifier 334 and 335, a low pass filter 336, and a receiver differential amplifier 337 and 338. It is configured to include).

The band pass filter 331 amplifies only a desired frequency band among signals received from the low noise amplifier 326 in the preposition unit 320.

The downlink local oscillator 332 converts the baseband analog received signal output from the bandpass filter 331 to a downlink frequency (2.67 GHz to 2.69 GHz) using a direct conversion method and performs a downlink local oscillation signal for I / Q demodulation. To provide.

The I / Q demodulator 332 I / Q demodulates the output signal of the bandpass filter 331 by using the downlink local oscillation signal, and divides it into four channels of I +, I-, Q +, and Q- and receives the gain amplifier ( 334, 335).

The receiver gain amplifiers 334 and 335 adjust and amplify the gain of the output signal of the I / Q demodulator 332 to stabilize the power and send the gain to the low pass filter 336. Through this process, the power of the input signal of the low pass filter 336 is maintained at a predetermined level or more so that the lack of gain of the low pass filter 336 is solved, and sufficient input power is supplied to the low pass filter 336. Can be.

The low pass filter 336 selectively passes only a band of a desired channel among the signals received from the receiver gain amplifiers 334 and 335 and sends them to the receiver differential amplifiers 337 and 338.

The receiver differential amplifiers 337 and 338 amplify a band of a desired channel among the signals received from the low pass filter 336 and output baseband analog received signals divided into four channels of I +, I-, Q +, and Q-. . Receive stage differential amplifiers 337 and 338 are baseband I + channel signals and I-channel signals. I-channel receiver stage differential amplifiers 337 are baseband Q + channel signals and Q-channel signals. 338 may be configured separately.

4 is a block diagram illustrating a schematic configuration of a terminal apparatus to which an RF transceiver of a 3G LTE mobile communication system using a direct conversion scheme (Zero-IF) according to an embodiment of the present invention is applied. The RF transceiver 300 of the 3G LTE mobile communication system using the direct conversion method (Zero-IF) according to the embodiment of the present invention can be applied to the RF unit 300.

A terminal device to which an RF transceiver of a 3G LTE mobile communication system using a direct conversion scheme (Zero-IF) according to an embodiment of the present invention is applied includes a terminal baseband transmitter for uplink transmission and a terminal base for downlink reception; It can be divided into band receiving end.

The terminal baseband transmitter for uplink transmission includes a CPU 416, a Low MAC transmitter 406, a physical channel transmit buffer 401, a channel encoder 402, a physical channel transmit modulator 403, and a DAC (DAC). Digital-Analog Converter (405), the path of the RF unit 300, and may include a L1 transmission control unit 404, High MAC (413), the power supply unit 415 to perform various control and power supply. have.

The CPU 416 sends the data to be transmitted to the Low MAC transmitter 406 using the 3G LTE mobile communication system. The low MAC transmitter 406 controls data traffic transmission between the CPU 416 and the channel encoder 402 under the control of the High MAC 413. The physical channel transmission buffer unit 401 forms an interface with an upper layer to store a data block to be transmitted on the physical channel. The channel encoding unit 402 receives the physical channel data block from the physical channel transmission buffer unit 401 and performs a Cyclic Redundancy Check (CRC) attachment, scrambling, channel encoding, and interleaving.

The physical channel transmission modulator 403 performs modulation and antenna symbol mapping for transmission from the bit string output from the channel encoder 402, and performs a preamble, pilot, and indicator channel. After the resource index is mapped to the physical index according to the frame structure, OFDM modulation is performed.

 The digital-analog converter (DAC) 405 converts the OFDM modulated digital signal output from the physical channel transmission modulator 403 into a baseband analog signal. As described above with reference to FIG. 3, the RF unit 300 converts a baseband analog signal into an electromagnetic wave (RF) using a direct conversion (Zero-IF) method and radiates it into the air through an antenna.

The L1 transmission control unit 404 cooperates with the High MAC 413 to perform general control such as setting parameters for the physical channel transmission buffer unit 404, the channel encoding unit 402, and the physical channel transmission modulation unit 403.

The terminal baseband receiver for downlink transmission includes an RF unit 300, an analog-to-digital converter and an automatic gain controller (AGC) 411, a physical channel reception demodulation unit 409, a channel decoding unit 408, It consists of a path of the physical channel receiving buffer unit 407, the low MAC receiving unit 412, the CPU 416, L1 receiving control unit 410, High MAC 413, power supply unit for performing various control and power supply ( 415).

As described above with reference to FIG. 3, the RF unit 300 converts an electromagnetic wave (RF) into a baseband analog signal using a direct conversion (Zero-IF) method and transmits the electrical signal into the terminal device. The ADC and AGC (Analog-Digital Converter & Automatic Gain Controller) 411 converts the baseband analog signal received by the RF unit 300 into an OFDM modulated digital signal and transmits the same to the physical channel reception demodulator 409.

The physical channel reception demodulator 409 performs time-frequency demapping according to OFDM demodulation and frame structure to extract received data for each physical channel, and processes uplink to extract uplink synchronization and channel state parameters. .

The channel decoding unit 408 performs channel estimation and demodulation for each physical channel, channel encoding, CRC error check, and the like. The physical channel reception buffer unit 407 stores a data block delivered by the channel decoding unit 408 to form a data interface with an upper layer. The low MAC receiver 412 is in charge of data traffic reception control between the CPU 416 and the channel decoder 408 under the control of the high MAC 113. The CPU 416 receives data to be received from the Low MAC receiver 412 using the 3G LTE mobile communication system.

The L1 reception control unit 410 cooperates with the High MAC 413 to perform general control such as setting parameters for the physical channel reception buffer unit 407, the channel decoding unit 408, and the physical channel reception demodulation unit 409.

Meanwhile, the High MAC 413 and the power supply unit 415 operate in both the terminal baseband transmitter for uplink transmission and the terminal baseband receiver for downlink reception.

The High MAC 413 provides packet scheduling, state management, automatic repeat request (ARQ), buffer management, broadcasting and paging control, and random access of uplink and downlink data. Is provided to the other functional blocks (416, 406, 404, 412, 410). The high MAC 413 may be implemented to be mounted in a digital signal processor (DSP).

The power supply unit 415 supplies power to a terminal device to which an RF transceiver of a 3G LTE mobile communication system using a direct conversion method (Zero-IF) according to an embodiment of the present invention is applied. Various voltages, such as 3.3V, 5V, and 12V, may be used for the power supply required for the terminal device.

Modules, functional blocks or means of the present embodiment may be implemented in a variety of known elements, such as electronic circuits, integrated circuits, ASICs (Application Specific Integrated Circuit), each may be implemented separately, or two or more may be integrated into one Can be.

Although the embodiments have been described for the understanding of the present invention as described above, it will be understood by those skilled in the art, the present invention is not limited to the specific embodiments described herein, but variously without departing from the scope of the present invention. May be modified, changed and replaced. Therefore, it is intended that the present invention cover all modifications and variations that fall within the true spirit and scope of the present invention.

FIG. 1 illustrates a conventional superheterodyne frequency conversion process.

Figure 2 shows the frequency conversion process of the direct conversion (Zero-IF) method used in the present invention.

3 is a block diagram showing a schematic configuration of an RF transceiver of a 3G LTE mobile communication system using a direct conversion scheme (Zero-IF) according to an embodiment of the present invention.

4 is a block diagram illustrating a schematic configuration of a terminal apparatus to which an RF transceiver of a 3G LTE mobile communication system using a direct conversion scheme (Zero-IF) according to an embodiment of the present invention is applied.

Claims (10)

A band pass filter for selectively passing a predetermined frequency band among the received signals; A downlink local oscillator for generating a downlink local oscillation signal for converting a carrier band signal to a downlink frequency using a direct conversion scheme (Zero-IF); An I / Q demodulator for dividing the output signal of the band pass filter into I / Q (In-phase / Quadrature-phase) by using the downlink local oscillation signal and dividing it into four channels of I +, I-, Q +, and Q- , A receiver gain amplifier for adjusting the gain of the output signal of the I / Q demodulator to stabilize the power; A low pass filter for selectively passing a band of a predetermined channel among the output signals of the receiver gain amplifier, and And a receiver differential amplifier for amplifying a band of the predetermined channel among the output signals of the low pass filter and dividing the signal into four channels. RF receiver in 3G LTE mobile communication systems using direct conversion (Zero-IF). The method of claim 1, The receiver gain amplifier and the receiver differential amplifier are respectively configured in plural in accordance with the I channel and the Q channel to process the received signal of the corresponding channel. The downlink frequency is 2.67GHz to 2.69GHz RF receiver in 3G LTE mobile communication systems using direct conversion (Zero-IF). The method of claim 1, An antenna for receiving electromagnetic signals in the air and converting the signals into electrical signals; A reception frequency bandpass filter for selectively passing a band corresponding to the downlink frequency among the output signals of the antenna, and Further comprising a low noise amplifier for amplifying the output signal of the reception frequency bandpass filter while suppressing noise and output to the bandpass filter RF receiver in 3G LTE mobile communication systems using direct conversion (Zero-IF). A first stage differential amplifier for amplifying the four channel bands among the transmission signals input to the four channels I +, I-, Q +, and Q-, An LC filter for selectively passing a band of a channel being used among the output signals of the first differential amplifier of the transmitter; A second differential amplifier of a transmitter for amplifying the baseband signal of the LC filter and dividing the signal into four channels; An uplink local oscillator for generating an uplink local oscillation signal for converting a baseband signal to an uplink frequency using a direct conversion scheme; An I / Q modulator for I / Q (In-phase / Quadrature-phase) modulating the output signal of the second stage differential amplifier using the uplink local oscillation signal and integrating it into one channel; A transmitter gain amplifier configured to adjust and amplify the gain of the output signal of the I / Q modulator to stabilize power; RF transmitter of 3G LTE mobile communication system using direct conversion method (Zero-IF). The method of claim 4, wherein The transmitter differential amplifier is configured in plural in accordance with the I channel and the Q channel to process the transmission signal of the corresponding channel, The uplink frequency is 2.53GHz to 2.55GHz RF transmitter of 3G LTE mobile communication system using direct conversion method (Zero-IF). The method of claim 4, wherein A high power amplifier for amplifying the power of the output signal of the transmitter gain amplifier; A transmission frequency bandpass filter for selectively passing a band corresponding to the uplink frequency among the output signals of the high power amplifier, and The antenna further converts the output signal of the transmission frequency bandpass filter into electromagnetic waves to radiate into the atmosphere. RF transmitter of 3G LTE mobile communication system using direct conversion method (Zero-IF). In-phase / Quadrature-phase (I / Q) demodulation of the carrier band received signal by direct conversion method (Zero-IF) and output as 4 channel baseband received signals divided into I +, I-, Q +, and Q- Receiving unit, Four-channel baseband transmission signals divided into I +, I-, Q +, and Q- are modulated by I / Q (Z-IF) to transmit one carrier band. A transmitter for outputting a signal, and An anterior part, the anterior part, An antenna for transmitting and receiving electrical signals with electromagnetic waves, And a preposition having a duplex branching the reception of the carrier band reception signal and the transmission of the carrier band transmission signal so that the transmitter and the receiver can share the antenna. RF transceiver of 3G LTE mobile communication system using direct conversion method (Zero-IF). The method of claim 7, wherein The duplex, A reception frequency bandpass filter for selectively passing a band corresponding to a downlink frequency among the received electrical signals received from the antenna, and And a transmission frequency bandpass filter for selectively passing a band corresponding to an uplink frequency among transmission electrical signals received from the transmitter. RF transceiver of 3G LTE mobile communication system using direct conversion method (Zero-IF). The method of claim 7, wherein The anterior portion, A low noise amplifier for amplifying the output signal of the reception frequency bandpass filter while suppressing noise; Further comprising a high power amplifier for amplifying the power of the output signal of the transmitter Terminal device of 3G LTE mobile communication system using direct conversion (Zero-IF). The method of claim 7, wherein The receiver is an RF receiver of the 3G LTE mobile communication system using the direct conversion method (Zero-IF) described in claim 1, The transmitter is an RF transmitter of a 3G LTE mobile communication system using the direct conversion method (Zero-IF) according to claim 4 or 5. RF transceiver of 3G LTE mobile communication system using direct conversion method (Zero-IF).

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