KR20050103671A - Transmission diversity apparatus of a mobile communication system - Google Patents

Abstract

The transmit diversity apparatus of the mobile communication system according to the present invention receives a first radio signal provided from a first transceiver and senses polarity, and transmits a radio signal whose polarity is changed based on the detected polarity of the first radio signal. It is characterized in that provided to the first transceiver.

As described above, the present invention can increase the capacity of the wireless network by providing a signal having good reception sensitivity to the mobile station by changing the polarity of the transmitted signal only by changing the polarity of the transmitted signal based on the polarity of the signal transmitted from the mobile station. .

In addition, the present invention has an effect of reducing the battery usage of the mobile station by providing a signal with good reception sensitivity to the mobile station.

Description

Transmit diversity device of mobile communication system {TRANSMISSION DIVERSITY APPARATUS OF A MOBILE COMMUNICATION SYSTEM}

The present invention relates to a mobile communication system, and more particularly, to a transmission diversity apparatus of a mobile communication system using radio wave polarity.

In general, code division multiple access (hereinafter, referred to as CDMA) mobile communication system has been developed from the conventional mobile communication standard mainly on voice, and has been developed to enable high-speed data transmission as well as voice. In the next-generation mobile communication standard, services such as voice, moving picture, internet search, etc. are available, and the communication line existing between the base station and the mobile station is largely a forward link from the base station to the mobile station. On the contrary, it is divided into a reverse link from the mobile station to the base station.

In order to transmit high-speed data in a mobile communication system, fading must be well overcome. Fading reduces the amplitude of the received signal from a few dB to tens of dB. Various diversity techniques are used to overcome this fading.

The CDMA scheme employs a rake receiver that receives diversity using the delay spread of the channel. Rake receiver is a receive diversity technique for receiving multipath signals. However, the diversity technique using the rake receiver has a disadvantage that it does not work when the delay spread is small.

On the other hand, time diversity techniques using interleaving and coding are used in the Doppler spreading channel. However, since this method does not have a large effect in the low speed Doppler channel, the spatial diversity method can effectively overcome the spreading in the indoor channel having low Doppler spread and the pedestrian channel which is the low speed Doppler channel.

On the other hand, spatial diversity is a method using two or more antennas, so that even if the signal transmitted by one antenna is reduced due to fading, it is possible to compensate for this by using the signal of the other antenna. The spatial antenna diversity is divided into receive antenna diversity using multiple receive antennas and transmit antenna diversity using multiple transmit antennas. However, it is recommended to use base station transmit antenna diversity because it is difficult to install receive antenna diversity in terms of area and cost.

Transmit antenna diversity includes "closed loop transmit diversity" which receives forward channel information from the mobile station and uses it in the transmission process, and "open loop transmit diversity" without feedback from the mobile station.

Here, the closed loop transmit diversity transmits a signal by weighting a transmission signal for each antenna so that the SNR at the mobile station antenna is maximized using channel information fed back from the mobile station. In addition, the open loop transmit diversity transmits the same signal through two mutually orthogonal paths without using feedback information, and a method of constructing orthogonal paths includes time division, frequency division, and division using code division. have.

Thus, since closed-loop transmit diversity uses channel information fed back from the mobile station, the closed-loop transmit diversity is superior to the open-loop transmit diversity when comparing the maximum performance of the closed-loop transmit diversity and the open-loop transmit diversity. However, in the case of closed-loop transmit diversity, a device for feeding back channel information to the mobile station must be further provided, which is complicated in its implementation and thus does not apply to the current system.

In addition, the open loop transmit diversity is simple in its configuration but has a problem in terms of performance.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem of the prior art, and by transmitting the transmitted signal by changing the polarity based on the polarity of the signal transmitted from the mobile station, a signal having good reception sensitivity to the mobile station can be provided to the mobile station only by changing the polarity of the transmitted signal. Another object of the present invention is to provide a transmit diversity apparatus of a mobile communication system capable of increasing a capacity of a wireless network.

In order to achieve the above object, the present invention provides a transmission diversity apparatus of a mobile communication system including a first transceiver for transmitting a first radio signal in response to receiving a second radio signal provided from a second transceiver. The second transceiver receives the first radio signal, detects polarity, transmits a radio signal whose polarity is changed based on the sensed polarity of the first radio signal, and provides the radio signal to the first transceiver. It is characterized by.

There may be a plurality of embodiments of the present invention, and a preferred embodiment will be described in detail below with reference to the accompanying drawings. Those skilled in the art will be able to better understand the objects, features and advantages of the present invention through this embodiment.

1 is a block diagram illustrating a mobile communication system to which a transmit diversity apparatus according to an exemplary embodiment of the present invention is applied, and includes a first transceiver 100 and a second transceiver 200. The first and second transceivers 100 and 200 may be mobile stations or base stations capable of transmitting and receiving. In the present invention, for convenience of description, the first transceiver 100 will be described as a mobile station, and the second transceiver 200 will be described as an eNB.

The second transceiver 200 transmits a second wireless signal having a predetermined polarity, and the configuration thereof includes a polarity converter 210, an up / down converter 220, a PA 230, an LNA 240, and a duplexer. And a polarity detector 260.

The up / down converter 220 receives the bit stream and converts the bit stream up or down according to the frequency band of the corresponding mobile communication system to provide it to the PA 230. The PA 230 amplifies the up or down bit stream. After the duplexer 250 and the antenna of the X-pole type is transmitted. In this way, the second transceiver 200 generates a second radio signal by amplifying the input bit stream in accordance with a frequency band, and provides the second radio signal to the first transceiver 100.

At this time, the second radio signal has a predetermined polarity and is transmitted from the second transceiver 200 to be provided to the first transceiver 100, and the polarity of the second radio signal is transmitted from the first transceiver 100 It will be converted according to the polarity of the received first wireless signal.

The first transceiver 100 receives a second radio signal having a predetermined polarity from the second transceiver 200 and transmits a first radio signal in response to the second radio signal. At this time, the polarity of the first and second radio signals is changed by various factors, for example, obstacles installed between the first and second transceivers 100 and 200 during transmission from the first transceiver 100.

The duplexer 250 of the second transceiver 200 receives the first radio signal of the first transceiver 100 and provides it to the LNA 240, and the LNA 240 amplifies the first radio signal.

The polarity detector 260 of the second transceiver 200 detects the polarity of the first wireless signal amplified by the LNA 240 and provides it to the polarity converter 210. The polarity converting unit 210 converts the polarity of the bit stream input based on the polarity information of the first wireless signal provided by the polarity detecting unit 260 or the polarity of the bit stream up or down in the up / down converter 210. To convert

The polarity-converted bit stream as described above, that is, the radio signal whose polarity is changed based on the polarity of the first radio signal is transmitted through the PA 230 and the duplexer 250, and the first and second transceivers 100 and 200. The polarity is changed according to the propagation path therebetween and transmitted to the first transceiver 100. That is, the first transceiver 100 may receive an optimal radio signal (a radio signal having good reception sensitivity) even if the polarity of the radio signal transmitted from the second transceiver 200 is changed by an obstacle on the propagation path. .

An operation process of the transmission diversity apparatus having such a configuration will be described with reference to FIG. 2. 2 is a flowchart illustrating an operation process of a transmit diversity apparatus according to the present invention.

Referring to FIG. 2, the second transceiver 200 receiving the bit stream transmits a second wireless signal through the up / down converter 210, the PA 230, and the duplexer 250, and the second wireless signal. The polarity of is changed according to the propagation path between the first and second transceivers 100 and 200 and is input to the first transceiver 100 (S300 and S302).

The first transceiver 100 transmits the first radio signal in response to the second radio signal, and the polarity of the first radio signal is changed according to an obstacle on the propagation path while being transmitted to the second transceiver 200. . The first radio signal whose polarity is changed as described above is received by the duplexer 250 of the second transceiver 200 (S304).

The first wireless signal received from the duplexer 250 is amplified by the LNA 240, the polarity detector 260 detects the polarity of the amplified first wireless signal and provides it to the polarity converter 210 ( 306).

The polarity converting unit 210 converts the polarity of the bit stream input to the second transmitting / receiving terminal 200 based on the polarity information of the first wireless signal provided from the polarity detecting unit 260 or to the up / down converter 220. By changing the polarity of the bit stream up or down by (S308).

Accordingly, the second transceiver 200 transmits a radio signal whose polarity is converted based on the polarity information of the first radio signal, and the radio signal whose polarity is converted is between the first and second transceivers 100 and 200. It is provided to the first transceiver 100 through a propagation path of.

As described above, the present invention changes the polarity and transmits a transmission signal based on the polarity of the received signal transmitted from the mobile station using the polarity converter, thereby providing a signal having good reception sensitivity to the mobile station using only the polarity converter to provide a capacity of the wireless network. Can be increased.

In addition, the present invention has an effect of reducing the battery usage of the mobile station by providing a signal with good reception sensitivity to the mobile station.

1 is a block diagram illustrating a mobile communication system to which a transmit diversity apparatus according to the present invention is applied;

2 is a flowchart illustrating an operation process of a transmit diversity apparatus according to the present invention.

<Description of the code | symbol about the principal part of drawing>

100: first transmitting and receiving end 200: second transmitting and receiving end

210: polarity converter 220: up / down converter

230: PA 240: LNA

250: duplexer 260: polarity detection unit

Claims (3)

A transmission diversity apparatus of a mobile communication system, comprising: a first transceiver transmitting a first radio signal in response to receiving a second radio signal provided from a second transceiver; The second transceiver is, Transmitter of the mobile communication system, characterized in that for detecting the polarity by receiving the first radio signal, and transmits the radio signal whose polarity is changed based on the sensed polarity of the first radio signal to provide to the first transceiver. City device. The method of claim 1, The second transceiver is, An up / down converter that receives a bit stream and ups or downs a radio wave band corresponding to the mobile communication system; A PA for amplifying the up or down bit stream, A duplexer configured to transmit the amplified bit stream as a second wireless signal through an antenna and receive a first wireless signal input through the antenna; An LNA for amplifying a first wireless signal received at the duplexer; A polarity sensing unit for sensing the polarity of the first wireless signal; And a polarity converter for changing the polarity of the bit stream based on the polarity sensed by the polarity detector. The method of claim 2, The polarity conversion unit, Transmit diversity apparatus of a mobile communication system, characterized in that for changing the polarity of the up or down bit stream.