• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
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  • 引用文献
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    • 专利摘要:
    end. The technical field to which the invention described in the claims belongs It is a technique for call switching of a code division multiple access terminal. I. The technical problem that the invention is trying to solve An apparatus and method for controlling soft handoff between base stations using different frequencies in a CDMA terminal are provided. All. Summary of Solution of the Invention A control method for a soft-handoff between a base station having a different frequency by a mobile terminal having a lake receiver having main passes and spare passes, and two local oscillators for the primary pass and the reserve pass. Is a first step of demodulating the signals of each base station having a different frequency at the same time, when the pre-pass local oscillator and the main pass local oscillator when the frequency is between the base stations having different frequencies, and the mobile terminal is directed to the mobile base station; A second process of changing the frequency of the main pass local oscillator according to the frequency of the mobile base station and communicating with the demodulated signal in the preliminary pass, and using the preliminary pass if the local oscillator for the main pass is stable. And a third process of communicating with a demodulated signal in said primary passes. It shall be. la. Important uses of the invention Used to allow a mobile terminal to make soft handoffs between base stations using different frequencies.
    公开号:KR19980066322A
    申请号:KR1019970001753
    申请日:1997-01-22
    公开日:1998-10-15
    发明作者:김준래
    申请人:김광호；삼성전자 주식회사；
    IPC主号:
    专利说明:

    Control device and method of terminal for soft-handoff between base stations with different frequencies
    The present invention relates to an apparatus and method for controlling handoff during call processing of a code division multiple access terminal in a wireless communication system, and more particularly, to an apparatus and method for controlling soft handoff between base stations using different frequencies. It is about.
    When a call is switched or handoffed, it is divided into two cases. That is, inter-cell call channel switching from one base station to another base station and call channel switching in one base station. Handoff between base stations is very important in mobile communication. In the conventional Analog Mobile Phone Service (AMPS), since the soft handoff is not supported, call disconnection occurs when the mobile terminal passes between base stations. I used to. In addition, even when communicating in a CDMA manner, soft handoff is not supported at base stations having different frequencies, which may result in disconnection of the call. Disconnected calls or clicking sounds during voice calls can be very unpleasant to the user. In addition, considering that the CDMA terminal will support data service in the future, if a call is lost during data transmission, important data may be lost, and data transmission using a portable terminal may be meaningless for the user.
    1 is a diagram illustrating a handoff situation. A, B, and C represent base stations, f represents a frequency, and the frequencies of each base station are f 1 , f 1 , and f 2 . The mobile terminal PT is allocated a frequency during the movement and communicates with its base station. And when he leaves his base station and enters a new base station, he must tune to the frequency of this new base station.
    2 is a block diagram of a conventional code division multiple access terminal. A first local oscillator 13 for generating a local oscillation signal of a first frequency, a first mixer 12 for mixing an RF signal received through the antenna 11 with a local oscillation signal of the first frequency, and a local oscillation signal of a second frequency A second local oscillator 16 for generating a signal; a second mixer 15 for mixing a signal output from the first mixer 12 with a local oscillation signal of the second frequency; and a plurality of signals for receiving a signal output from the second mixer 15; Decoder for inputting and decoding the signal output from the combiner 23 and the combiner 23 consisting of a combiner 23 for supplying the paths of the path and the signals input from the plurality of paths to a single output terminal without mutual interference; 24 and a signal for controlling the oscillation frequencies of the local oscillators 13, 16, and 24, controlling the connection of the plurality of paths and the combiner 23, and controlling the operation of the decoder 24. It is composed of 40. As shown, the number of passes is n, i.e., first through n-th fingers 18-21. And the signals received by them have a certain time difference from each other.
    The situation in which the handoff occurs and its operation will be described in detail with reference to FIGS. 1 and 2 as follows. If the frame offsets are the same between base stations A and B, which have the same frequency, soft handoff occurs. However, there is a case where a call is disconnected due to switching between the base station A and the base station C having different frequencies, or the base station B and the base station C. The area marked ① is an area common to the base station service area and the base station service area, and frequencies f 1 and f 2 corresponding to each base station are mixed. Nevertheless, since the terminal as shown in FIG. 1 has only one first local oscillator 13, it cannot simultaneously support two frequencies. In other words, since the frequency used by the terminal to receive the signal of the base station and converts it into a baseband signal is limited to one, signals of two base stations using different frequencies cannot be processed simultaneously.
    Accordingly, an object of the present invention is to provide an apparatus and method for controlling soft handoff between base stations using different frequencies in a CDMA terminal.
    1 illustrates a handoff situation
    2 is a block diagram of a conventional code division multiple access terminal
    3 is a block diagram of a code division multiple access terminal according to an embodiment of the present invention;
    4 is a diagram illustrating a frequency and a base station of a signal used for demodulation during handoff;
    Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals have the same reference numerals as much as possible even if displayed on different drawings. Also, in the following description, many specific details such as components of specific circuits are shown, which are provided to help a more general understanding of the present invention, and the present invention may be practiced without these specific details. It is self-evident to those of ordinary knowledge in Esau. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.
    3 is a block diagram of a code division multiple access terminal according to an embodiment of the present invention. A first local oscillator 13 for generating a local oscillation signal of a first frequency, a first mixer 12 for mixing an RF signal received through the antenna 11 with a local oscillation signal of the first frequency, and a local oscillation signal of a second frequency A second local oscillator 16 for generating a signal; a second mixer 15 for mixing a signal output from the first mixer 12 with a local oscillation signal of a second frequency; and a third local generator for generating a local oscillation signal of a third frequency. An oscillator 24, a third mixer 14 for mixing the RF signal received through the antenna 11 with a local oscillation signal of the third frequency, and a signal output from the third mixer 14 with the local oscillation signal of the second frequency. A fourth mixer 17 for mixing, a plurality of passes for receiving the output of the second mixer 15, that is, first to n-th fingers 18 to 21, and a spare finger 22 for receiving the output of the fourth mixer 17, the fingers 18 Signals input from ˜21, 22 to a single output Lake receiver 30 comprising a combiner 23 for supplying without interference, a decoder 24 for inputting and decoding the signal output from the combiner 23, and a signal for controlling the oscillation frequency of each of the local oscillators 13, 16, 24 And a controller 40 which controls the connection of the plurality of passes or preliminary passes with the combiner 23 and controls the operation of the decoder 24.
    Referring to FIG. 1 and FIG. 3, the situation in which the handoff occurs and its operation will be described in detail. If the frame offsets are the same between base stations A and B, which have the same frequency, soft handoff occurs. At this time, the spare finger 22 of FIG. 1 does not perform any operation. In other words, communication is performed using only the first to nth fingers 18 to 21. However, the base station A and the base station C having different frequencies, or the base station B and the base station C, use the spare finger 22 to perform a handoff. Since the frequency f 1 and f 2 are mixed when the terminal passes the region indicated by ① of FIG. 2, the first local oscillator 13 of FIG. 1 generates a local oscillation signal suitable for the frequency f 1 and processes the signal in the lake receiver 30. The third local oscillator 14 generates a local oscillation signal suitable for the frequency f 2 and is used to generate a signal to be processed by the spare finger 22. In this way, when demodulating the signals of the base stations having different frequencies at the same time and completely passing toward the base station C, the frequency of the first local oscillator 13 is changed to be suitable for f 2 . While the first local oscillator 13 is sufficiently stabilized, the use of the spare finger 22 is stopped.
    4 is a diagram illustrating a frequency and a base station of a signal used for demodulation during handoff. (4a) shows a conventional case, and there is a case where a call is disconnected due to a sudden switching between base stations having different frequencies. However, as shown in (4b), this is not the case according to the embodiment of the present invention.
    Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.
    As described above, the present invention can increase the stability of a call by supporting soft-handoff between base stations using different frequencies, which is very good for supporting a service requiring call continuity such as data transmission.
    权利要求:
    Claims (2)
    [1" claim-type="Currently amended] A first local oscillator for generating a local oscillation signal of a first frequency, a first mixer for mixing a radio signal received through an antenna with the local oscillation signal of a first frequency, and a local oscillation signal for a second frequency; A second local oscillator, a second mixer for mixing a signal output from the first mixer with a local oscillation signal of the second frequency, a plurality of paths for receiving the output of the second mix, and a signal input from each path In a control device for a soft-handoff between base stations having different frequencies, a mobile terminal having a lake receiver composed of a combiner for supplying to a single output terminal without mutual interference is provided. A third local oscillator generated; a third mixer for mixing the radio signal with a local oscillation signal of the third frequency; and a signal output from the third mixer; A fourth mixer for mixing with a true signal, a preliminary pass provided in the lake receiver, for receiving the output of the fourth mixer and transmitting the output of the fourth mixer to the combiner when the mobile terminal is located between base stations having different frequencies; A decoder that decodes the signal output from the combiner, and when the mobile terminal detects that the base station is between different base stations with different frequencies, it drives the preliminary pass along with the plurality of passes, and the mobile terminal completely passes over to the mobile base station. When the first local oscillator is detected, the frequency of the first local oscillator is changed to match the frequency of the mobile base station, and the combiner takes only the signal demodulated in the preliminary pass. Stop driving the spare pass and let the combiner take only the demodulated signal in the multiple passes. Device characterized by consisting of a control unit for.
    [2" claim-type="Currently amended] A control method for a soft-handoff between a base station having a different frequency by a mobile terminal having a lake receiver having main passes and spare passes, and two local oscillators for the primary pass and the reserve pass. Is a first step of demodulating the signals of each base station having a different frequency at the same time, when the pre-pass local oscillator and the main pass local oscillator when the frequency is between the base stations having different frequencies, and the mobile terminal is directed to the mobile base station; A second process of changing the frequency of the main pass local oscillator according to the frequency of the mobile base station and communicating with the demodulated signal in the preliminary pass, and using the preliminary pass if the local oscillator for the main pass is stable. And a third process of communicating with a demodulated signal in said primary passes. How to.
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    同族专利:
    公开号 | 公开日
    KR100208944B1|1999-07-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1997-01-22|Application filed by 김광호, 삼성전자 주식회사
    1997-01-22|Priority to KR1019970001753A
    1998-10-15|Publication of KR19980066322A
    1999-07-15|Application granted
    1999-07-15|Publication of KR100208944B1
    优先权:
    申请号 | 申请日 | 专利标题
    KR1019970001753A|KR100208944B1|1997-01-22|1997-01-22|Control apparatus of terminal for soft-handoff between base stations having the different frequency|
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