• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention is to adjust the output characteristics of the digital terminal for personal communication to improve the phenomenon that the AM / AM characteristics and AM / PM characteristics appear in the process of amplifying a low power transmission signal modulated to a predetermined frequency signal for high power transmission through the antenna An apparatus, comprising: a baseband processor for varying the amplification degree of a transmission power based on a power level of a received signal received by an antenna, and for performing coding and decoding of a transmitted and received signal; A digital terminal for personal communication comprising a modulator for modulating a transmission signal into a high frequency signal of a predetermined band, comprising: a first attenuator for performing a predetermined level of attenuation on a transmission signal output from the modulator at low power transmission; On / off switching according to the transmit power control signal applied from the processor That such a switching unit, and as the switching-on the driving portion is characterized in that configured by a second attenuator running the signal attenuation at the time of high-power transmission.
    公开号:KR19980044347A
    申请号:KR1019960062426
    申请日:1996-12-06
    公开日:1998-09-05
    发明作者:전상덕
    申请人:유기범；대우통신 주식회사；
    IPC主号:
    专利说明:

    Output Characteristic Control Device of Digital Terminal for Personal Communication
    BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission apparatus of a digital terminal for personal communication. In particular, a phenomenon in which AM / AM characteristics and AM / PM characteristics appear during amplification of a low power transmission signal modulated to a predetermined frequency signal to transmit a high power through an antenna It relates to a device for adjusting the output characteristics of a digital terminal for personal communication.
    Recently, with the rapid development of communication technology, a personal communication system has been developed and rapidly spread so that individuals can communicate with others while moving from one place or one place to another. The communication system is largely divided into TDMA (Time Division Multiple Access) method and CDMA (Code Division Multiple Access) method. Among them, many countries adopt this method because system stability and technology completion are relatively high. have.
    Fig. 1 shows the internal structure of the above-described TDMA personal communication terminal. In Fig. 1, reference numeral 1 denotes an antenna for data transmission and reception with a base station (not shown), and 2 denotes by this antenna 1 The low noise amplifier section 3, which consists of a low noise amplifier for amplifying the received frequency signal, etc., 3 is a demodulation section for demodulating the original code signal from the frequency signal inputted through the low noise amplifier section 2. As shown in FIG.
    Also, reference numeral 4 denotes interleaving, block coding, and convolutional coding for data transmitted and received through the demodulator 3 and the modulator 9 to be described later according to the GSM standard. A baseband processor for executing coding, etc., and 5 is a LAPDm processor for processing control data transmitted / received according to a LAPDm standard with a base station (not shown).
    Further, reference numeral 6 denotes a speaker for outputting an audio signal transmitted from the opposite station terminal as an audible voice, 7 is a microphone as a transmitter for converting and inputting a user's voice input as an electrical signal, and 8 is the microphone 7 A voice processing unit for converting an analog voice signal input from the digital data into digital data and converting the voice data applied through the baseband processing unit 24 into an analog voice signal and outputting the analog voice signal to the speaker 26. Reference numeral 9 denotes a modulator for modulating the transmission data output through the baseband processor 4 into a predetermined frequency signal, and 10 denotes an amplifier for amplifying the frequency signal modulated by the modulator 9.
    Reference numeral 11 denotes a key input unit having a plurality of numeric keys (10-keys) and function keys, 12 denotes a display unit such as a liquid crystal display device for displaying various operation states or operation states of the terminal, and 13 denotes the above. Control unit for controlling the terminal in accordance with the operation signal input through the key input unit 11 and the operation control of the operation state of the terminal through the transmission and reception with the base station 2 through the LAPDm processing unit 5, 14 is this control unit The program storage unit 15, in which the operation program of (13) is stored, is a data storage unit in which various processing data related to the operation of the control unit 13 are stored.
    That is, in the personal communication terminal having the above configuration, when the user dials the receiver's telephone number through the key input unit 11, the control unit 13 connects the LAPDm processing unit 5 and the baseband processing unit 4 to each other. By generating the control data for the call connection through the modulator 9 and the amplification unit 10 and transmits it to the base station through the antenna 1 to form a communication path for bidirectional communication, the antenna (1) The signal received by is applied to the voice processing unit 8 via the baseband processing unit 4, and then output through the speaker 6, which is a receiver, after a predetermined process such as amplification, while the microphone 7 The voice signal of the caller input through the voice signal is transmitted through the antenna through the voice processor 8 and the baseband processor 4 so that a call between the sender and the receiver can proceed.
    On the other hand, the modulation and transmission process performed in the wireless transmitter in detail, GMSK (Gaussian Minimum Shift Keying) low frequency signal output from the baseband processing unit 4 is mixed with a radio frequency (RF) signal is modulated into a high frequency transmission signal As shown in FIG. 2B, the amplifier 10 amplifies the input signal of (a) to a predetermined level in order to increase the transmission power of the signal modulated by the above-described process. At this time, as shown in (b) 도 of FIG. 2, the ripple level, which is only 0.5 to 1 dB before amplification, is deformed and output in the form of a level of about 3 to 4 dB exceeding ± 1 dB, which is an allowable value according to the GSM standard after amplification. As a result, there is a problem in that the quality of the signal transmitted through the antenna 1 is degraded.
    SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in the process of amplifying a low power transmission signal modulated with a predetermined frequency signal for high power transmission through an antenna, the AM / AM characteristics and AM / PM characteristics of the output signal waveform are increased. It is an object of the present invention to provide a device for adjusting the output characteristics of a digital terminal for personal communication to improve the phenomenon.
    1 is a block diagram schematically showing the configuration of a general time division multiple access (TDMA) personal communication terminal.
    2 is a waveform diagram showing a transmission power amplification waveform;
    3 is a circuit diagram showing an output characteristic adjusting apparatus for a digital terminal for personal communication according to an embodiment of the present invention;
    Explanation of symbols on the main parts of the drawings
    1 antenna 2 low noise amplifier
    3: demodulation unit 4: baseband processing unit
    5: LAPDm processing unit 6: speaker
    7: microphone 8: voice processing unit
    9: modulator 10, 20: amplifier
    11: key input unit 12: display unit
    13 control unit 14 program storage unit
    15: data storage 21: first filter circuit
    22: Band Pass Filter (BPF)
    23: second filter circuit 24: pre-amplifier (Pre-AMP)
    25: output characteristic adjustment circuit
    26: power amplifier module (PAM)
    C1 to C3: Capacitor L1 to L3: Inductor
    D: Diode Q: Transistor
    R1 to R4: resistance
    An output characteristic adjusting apparatus according to the present invention for achieving the above object is a baseband that performs the coding and decoding of the transmitted and received signals while varying the amplification degree of the transmission power based on the power level of the received signal received by the antenna A digital communication terminal for personal communication comprising a processing unit and a modulation unit for modulating a transmission signal output from the baseband processing unit into a high frequency signal of a predetermined band, wherein a predetermined level of attenuation is applied to the transmission signal output from the modulation unit at low power transmission. A first attenuator to be executed, a switching unit to be switched on / off in response to a transmission power control signal applied from the baseband processor, and a second attenuator to perform signal attenuation at high power transmission as the switching unit is driven on; Characterized in that configured to include.
    That is, according to the present invention having the above-described configuration, the attenuation is differentiated through the first attenuator at low power transmission and the second attenuator at high power transmission according to the level of the transmission power control signal applied from the baseband processor. By doing so, it is possible to improve the AM / AM conversion and AM / PM conversion characteristics generated when amplifying transmission power.
    Hereinafter, with reference to the accompanying drawings will be described an embodiment according to the present invention.
    FIG. 3 is a circuit diagram illustrating an output characteristic adjusting apparatus of a digital terminal for personal communication according to an embodiment of the present invention, in which components which perform the same functions as those shown in FIG. Will be omitted.
    In FIG. 3, reference numeral 20 denotes a transmitting end side amplifying unit of a digital terminal for personal communication equipped with an output characteristic adjusting apparatus according to the present invention.
    Reference numeral 22 denotes a band pass filter (BPF) that detects only a frequency signal in the 890 to 915 MHz band among the high frequency transmission signals output from the modulator 9, and 21 and 23 denote first and second filters for impedance matching, respectively. The circuit 24 is a pre-amp for amplifying a high frequency signal output from the band pass filter BPF to a predetermined level.
    In addition, reference numeral 25 denotes an output characteristic adjusting circuit for adjusting the output signal output characteristic of the RF transmitter, and the output characteristic adjusting circuit 25 is a pin diode as a first attenuator for signal attenuation during low power transmission. (D) and on / off switching are driven in accordance with the inductor L3 as a second attenuator for adjusting the signal attenuation at the time of high power transmission and the transmission power control signal V apc applied from the baseband processor 4 The transistor Q is configured to bypass the DC level signal through the inductor L3.
    In addition, reference numeral 26 denotes an end amplifier (PAM) for performing power amplification of a transmission signal transmitted through the antenna 1 based on the transmission power control signal Vapc from the baseband processor 4. )to be.
    Next, the operation of the device having the above configuration will be described.
    The RF signal of the 900 MHz band output from the modulator 9 is applied to the band pass filter (BPF) 22 through the first filter 21 for impedance matching, which is predetermined by the band pass filter 22. In addition to the frequency band, the noise component mixed in the modulation process is removed and input to the preamplifier 24 through the second filter 23.
    The preamplifier 24 first amplifies the transmission frequency signal applied through the second filter 23 to a predetermined level and supplies the preamplifier 24 to an output characteristic adjusting circuit 25 installed at the rear stage. In the reference numeral 25, different attenuation occurs during low power transmission and high power transmission according to the level of the transmission power control signal Va apc applied from the baseband processor 4.
    The baseband processor 4 outputs a predetermined transmission power control signal V apc for adjusting the power amplification of the transmission signal based on the power level of the signal received through the antenna 1, and controls for low power amplification. When a signal, i.e., a transmission power control signal of less than a predetermined level is outputted, the transistor Q inside the output characteristic adjusting circuit 25 is turned off, so that only attenuation by the pin diode D occurs at this time. As the AM / AM characteristic is improved, the ripple level appearing in the output signal waveform as shown in Fig. 2C is within the allowable range.
    On the other hand, when the control signal for high power amplification, that is, the transmission power control signal Vapc of a predetermined level or more is output from the baseband processor 4, the transistor Q provided inside the output characteristic adjusting circuit 25. When the high level is applied to the base end of the transistor Q is turned on, one end of the inductor L3 connected to the collector end is connected to the ground potential through the emitter end.
    As a result, the DC component having a predetermined level among the signals output through the diode D is bypassed to the ground through the inductor L3 and the transistor Q, and as a result, in the terminal amplifier (PAM) 26 of the rear stage. The generated AM / PM conversion characteristic is improved.
    That is, according to the embodiment, the digital terminal for personal communication is designed to improve the phenomenon of AM / AM characteristics and AM / PM characteristics in the process of amplifying a low power transmission signal modulated with a predetermined frequency signal for high power transmission through an antenna. The output characteristic adjusting device can be realized.
    On the other hand, the present invention is not limited to the above embodiments and can be modified in various ways without departing from the technical gist of the present invention.
    As described above, according to the present invention, AM / AM and AM / AM generated in the transmission power amplification process by automatically adjusting the attenuation ratio for the modulator output signal of the RF transmitter based on the transmission power control signal applied from the baseband processor. PM characteristics can be improved.
    权利要求:
    Claims (1)
    [1" claim-type="Currently amended] A baseband processor that variably adjusts the amplification degree of the transmission power based on the power level of the received signal received by the antenna, and performs coding and decoding of the transmitted and received signals, and a transmission band output from the baseband processor A digital terminal for personal communication comprising a modulator for modulating a high frequency signal of
    A first attenuator for performing a predetermined level of attenuation on a transmission signal output from the modulator when low power is transmitted;
    A switching unit driven on / off switching according to a transmission power control signal applied from the baseband processor;
    And a second attenuator configured to perform signal attenuation during high power transmission as the switching unit is driven on.
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    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1996-12-06|Application filed by 유기범, 대우통신 주식회사
    1996-12-06|Priority to KR1019960062426A
    1998-09-05|Publication of KR19980044347A
    优先权:
    申请号 | 申请日 | 专利标题
    KR1019960062426A|KR19980044347A|1996-12-06|1996-12-06|Output Characteristic Control Device of Digital Terminal for Personal Communication|
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