KR20030065197A - Device of diversity having directivity in wireless digital assistant - Google Patents

Abstract

PURPOSE: A directional diversity device for a portable wireless terminal is provided to perform directional diversity by one antenna by changing the directivity of a directional antenna and receiving a signal with a different path. CONSTITUTION: The first and second conductors(121,122) change directivity. The directivity of a directional antenna(110) is changed according to a connection state of the first and second conductors(121,122) and the ground. The directional antenna(110) receives a wireless signal through a path of a corresponding direction, and transmits the wireless signal to a duplexer(130). A signal splitter(190) splits a receiving signal outputted from an IF(Intermediate Frequency) amplifier(180). A level detection and path selector(210) detects a level of the signal obtained in the signal splitter(190), and generates the first and second path selection signals for selecting the path of the receiving signal, according to the detected level. The first and second switches(123,124) perform switching operations according to the first and second path selection signals outputted from the level detection and path selector(210), and selectively connect the first and second conductors(121,122) to the directional antenna(110) so that the directivity is changed.

Description

DEVICE OF DIVERSITY HAVING DIRECTIVITY IN WIRELESS DIGITAL ASSISTANT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to directional diversity in a portable wireless terminal. In particular, the portable wireless terminal includes a directional antenna, and includes a directional antenna and changes the directivity of the directional antenna to allow reception of a signal having a different path. The present invention relates to a directional diversity device of a portable wireless terminal capable of low directional diversity.

In general, a wireless base station apparatus is used to connect a mobile communication terminal to a mobile communication terminal or a wired communication network, and when a terminal receives a transmission signal transmitted from the base station apparatus, a radio wave transmitted from the base station is widely spread. Therefore, the service network is in the flow of radio waves, and when the radio waves are received by the antenna of the receiver (terminal), the reflected waves are received in various paths.

Due to the different path lengths of these reflected waves, the received signals actually have a phase difference, which is why the reception level at a certain point is very strong, and at another point it is very weak or impossible to receive a signal (fading it). Phenomenon).

In other words, when the signals having the phase difference are received together, they are canceled and canceled when they are opposite phases, and when they are the same phase, the signals are summed and become larger signals.

In this case, there is no problem in the case where the received signals are summed up to become a large level received signal, but a serious problem occurs because the communication is disconnected at the point where the received signal is out of phase and canceled out.

In order to solve this problem, there is a method of increasing the output of the base station apparatus at present. This method is only a temporary solution and cannot be regarded as a fundamental solution. In this case, the terminal may cancel the received signal as described above. To avoid the point.

Another method is to implement diversity such that the reception path is multipath. Here, diversity is a method for obtaining a plurality of received signals having different electric field strengths or signal-to-noise ratios in order to alleviate the effects of fading. The types of diversity include time diversity, frequency diversity, and spatial diversity.

Spatial diversity (directional diversity), which is easy to implement among the diversity, includes installing a plurality of antennas in directions different from each other, receiving signals of the multi-path, and receiving signals of the antenna located in the best path. It is a method to select by signal.

However, this method uses a plurality of antennas to receive signals of a multipath and implements a plurality of signal processing apparatuses (for example, amplifiers) corresponding thereto. This is difficult to apply.

For reference, all current portable wireless terminals are implemented to receive signals in any direction by using an omnidirectional antenna.

Accordingly, the present invention is proposed to overcome the fading phenomenon occurring in the general portable wireless terminal as described above,

An object of the present invention is to provide a directional antenna in a portable wireless terminal, and to change the directivity of the directional antenna so that a signal having a different path can be received. A diversity device.

Technical means for achieving the object of the present invention as described above,

A duplexer for switching the receive and transmit signals, a high power amplifier (HPA) for power amplification of the transmit signal, a low noise amplifier (LNA) for the amplification of the received signal, a low noise amplifier signal and an output signal of the local oscillator A portable wireless terminal comprising a frequency mixer (mixer) to detect and an intermediate frequency amplifier for amplifying an intermediate frequency signal output from the frequency mixer,

First and second conductors for changing directivity;

A directional antenna which varies in directivity according to a connection state between the first and second conductors and the ground, and receives a radio signal through a path in a corresponding direction and transmits the radio signal to the duplexer;

A signal divider for distributing the received signal output from the intermediate frequency amplifier;

A level detection and path selector for detecting a level of a signal obtained by said signal splitter and generating first and second path selection signals for selecting a path of a received signal according to the detection level;

First and second switching operations corresponding to the first and second path selection signals output from the level detection and path selector to selectively connect the first and second conductors and the directional antenna to change the directivity. It is characterized by including a switch.

In the above description, the first and second conductors are conductors RF-separated from a copper foil pattern of a printed circuit board (PCB) or a battery on which an internal circuit portion of a portable wireless terminal is mounted.

1 is a view showing the configuration of a directional diversity device of a portable wireless terminal according to the present invention.

<Explanation of symbols for the main parts of the drawings>

110 ..... Antenna

121, 122 ..... First and second conductors

123, 124 ..... First and second switch

130 ..... duplexer

140 ..... High Power Amplifier

150 ..... Low Noise Amplifier

190 ..... signal splitter

210 ..... Level Detection and Path Selector

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention according to the technical spirit as described above.

1 is a block diagram of an embodiment of a directional diversity apparatus of a portable wireless terminal according to the present invention.

Reference numerals 121 and 122 denote first and second conductors for changing directivity, and reference numeral 110 denotes directivity changes according to a connection state between the first and second conductors 121 and 122 and ground. , A directional antenna for receiving a radio signal through a path in a corresponding direction and transmitting it to a duplexer 130 at a later stage, a reference numeral 130 denotes the duplexer for receiving and transmitting signal switching, and a reference numeral 140 denotes a power of a transmission signal. Reference numeral 150 denotes a low noise amplifier (LNA) for amplifying a received signal, and reference numeral 170 denotes a signal of the low noise amplifier 150 and an output signal of the local oscillator 160. Denotes a frequency mixer (mixer) that detects the intermediate frequency by mixing P, and reference numeral 180 denotes an intermediate frequency amplification that amplifies the intermediate frequency signal output from the frequency mixer 170. It represents an.

In addition, reference numeral 190 denotes a signal divider for distributing the received signal output from the intermediate frequency amplifier 180, and reference numeral 210 detects a level of a signal obtained from the signal divider 190 and receives the signal according to the detection level. A level detection and path selector for generating first and second path selection signals for selecting a path of a signal, and reference numerals 123 and 124 denote first and second paths output from the level detection and path selector 210. The first and second switches may be connected to the first and second conductors 121 and 122 and the directional antenna 110 in a switching operation corresponding to the selection signal to change the directivity.

The operation of the directional diversity device of the portable wireless terminal according to the present invention configured as described above will be described in detail as follows.

First, in the present invention, the directivity of the antenna is changed by using the first and second conductors 121 and 122 using the copper foil pattern and the ground in a component or a circuit configuration (for example, a PCB and a battery) having a large conductor volume. .

That is, the directional antenna 110 and the first and second conductors 121 and 122 are connected by using the first and second switches 123 and 124 using a pin diode, which is a semiconductor device, or two conductors are connected. The dividing action changes the directivity of the directional antenna 110.

In this case, the change in directivity is to implement directional diversity using one antenna.

In general, when diversity is implemented, spatial diversity, polarization diversity using vertical polarization and horizontal polarization, and angle (directional) diversity (also referred to as directional diversity) in which a directional antenna is directed toward different propagation directions are the same. Frequency diversity for transmitting information using a plurality of carriers, time diversity for transmitting the same information to a plurality of time slots, and spreading modulation of a transmission signal to identify a multipath component using a RAKE reception method. The multipath diversity scheme may be implemented.

Particularly in the case of spatial diversity, an unorrelation branch is obtained by installing two omni directional antennas between half-wavelengths of a carrier wave.

The strength of signals received from two antennas with multiple paths may be different from each other. This spatial diversity selects a good signal from two signals to improve reception sensitivity. And the vertical diversity scheme can be used. Horizontal diversity is a method in which antennas are spaced horizontally, and a horizontal reflection of multiple reflected wave components reflected from a building or the like is used in a mobile communication environment. In this case, the correlation coefficient of the horizontal diversity is influenced by the separation interval of the two antennas and the arrival direction of the radio wave. Next, vertical diversity uses two antennas vertically spaced apart, and the correlation coefficient is only affected by two antenna spacings. In order to avoid correlation, a larger antenna distance is required than horizontal.

However, such a conventional spatial diversity method is difficult to apply to a modern portable wireless terminal that requires a plurality of antennas (at least two or more), which is easy to carry and requires miniaturization and light weight.

Accordingly, in the present invention, the directivity of one directional antenna is changed by using a copper foil pattern of a conductor already provided in the terminal, and directional diversity is implemented using the same.

That is, when the receiver (portable wireless terminal) is located in the radio valley while moving and the received signal level becomes extremely weak and becomes unable to talk, the receiver detects the level at high speed and selects a reception signal in another direction.

For example, initially, the first switch 123 is connected to the first conductor 121, the second switch 124 is connected to the ground, and the second conductor 122 is switched in a manner of being separated from the second conductor 122.

In such a state, the directional antenna 110 is connected to the first conductor 121 to have a specific directivity, and receives only a signal received in the direction (referred to as a "first path signal" for convenience) to the duplexer ( 130).

The low noise amplifier 150 suppresses the noise of the first path signal received by the duplexer 130 and amplifies only the signal component, and the frequency mixer 170 controls the signal received from the low noise amplifier 150 and the local oscillator ( The intermediate frequency is detected by mixing the local oscillation signal output from 160).

The detected intermediate frequency is amplified to a predetermined level by the intermediate frequency amplifier 180 and then transmitted to the signal processing device at a later stage as a received signal through the signal divider 190, and is simultaneously separated through coupling to detect and level the path. Is passed to the selector 210.

The level detection and path selector 210 detects the level of the received signal coupled and input, and compares the detected level with the reference level to check the state of the received signal. When the detection level is higher than or equal to the reference result as a result of the confirmation, the signal received by the current directing direction is in a good state (a good reception sensitivity) and thus maintains the current directing direction.

However, if the detection level is less than the reference level as a result of the check, the reception sensitivity is lowered, so that the first path selection signal is turned off and only the second path selection signal is turned on in order to receive signals in different directions (different paths).

When the first path selection signal is turned off, the first switch 123 disconnects the first conductor 121 from the directional antenna 110 and connects the directional antenna 110 to ground.

In addition, when the second path selection signal is turned on, the second switch 124 changes the directivity by connecting the second conductor 122 and the directional antenna 110. That is, a signal of a path different from the previous reception path is received.

By the operation of the second switch 124 as described above, the directional antenna 110 receives a signal of a different path from the previous path (referred to as a "second path signal" for convenience) and transmits it to the duplexer 130.

The low noise amplifier 150 suppresses the noise of the second path signal received by the duplexer 130 and amplifies only the signal component, and the frequency mixer 170 receives the signal received from the low noise amplifier 150 and the local oscillator ( The intermediate frequency is detected by mixing the local oscillation signal output from 160).

The detected intermediate frequency is amplified to a predetermined level by the intermediate frequency amplifier 180 and then transmitted to the signal processing device at a later stage as a received signal through the signal divider 190, and is simultaneously separated through coupling to detect and level the path. Is passed to the selector 210.

The level detection and path selector 210 detects the level of the received signal coupled and input, and compares the detected level with the reference level to check the state of the received signal. When the detection level is higher than or equal to the reference result as a result of the confirmation, the signal received by the current directing direction is in a good state (a good reception sensitivity) and thus maintains the current directing direction.

However, if the detection level is less than the reference level as a result of the confirmation, the reception sensitivity is deteriorated, so that the first path selection signal is turned on and the second path selection signal is turned off in order to receive signals in different directions (different paths). Perform the action.

That is, in the present invention, when a receiver (portable wireless terminal) is located in a radio valley while moving and the received signal level becomes extremely weak, and the call becomes impossible, the method detects the level at high speed and selects a reception signal in another direction. Thus, directional diversity can be realized with only one directional antenna.

As described above, the present invention provides a method of changing the directivity of the directional antenna by using a directional antenna and using a copper foil pattern of a PCB or a battery, which is a large volume of conductor already implemented inside the terminal. In addition, it is possible to receive signals of different paths, and thus, there is an advantage of implementing directional diversity with one antenna.

Claims (3)

A duplexer for switching the receive and transmit signals, a high power amplifier (HPA) for power amplification of the transmit signal, a low noise amplifier (LNA) for the amplification of the received signal, a low noise amplifier signal and an output signal of the local oscillator A portable wireless terminal comprising a frequency mixer (mixer) to detect and an intermediate frequency amplifier for amplifying an intermediate frequency signal output from the frequency mixer, First and second conductors for changing directivity; A directional antenna which varies in directivity according to a connection state between the first and second conductors and the ground, and receives a radio signal through a path in a corresponding direction and transmits the radio signal to the duplexer; A signal divider for distributing the received signal output from the intermediate frequency amplifier; A level detection and path selector for detecting a level of a signal obtained by said signal splitter and generating first and second path selection signals for selecting a path of a received signal according to the detection level; First and second switching operations corresponding to the first and second path selection signals output from the level detection and path selector to selectively connect the first and second conductors and the directional antenna to change the directivity. Directional diversity device of a portable wireless terminal comprising a switch. The method of claim 1, wherein the first and second conductors, A directional diversity device of a portable wireless terminal, characterized in that the conductor is RF separated from a large-volume printed circuit board (PCB) or a copper foil pattern of a battery on which the internal circuit portion of the portable wireless terminal is mounted. The method of claim 1, wherein the level detection and path selector, The directional diversity device of a portable wireless terminal, characterized in that for detecting the level of the received signal using the field strength (RSSI) typically detected in the existing wireless terminal.