JPH11284567A - Wireless transmission / reception method and apparatus - Google Patents

Abstract

(57) [Problem] To provide a wireless transmission / reception method and apparatus excellent in monitoring of a wireless signal without deteriorating signal transmission characteristics. An omnidirectional antenna is used for transmitting a broadcast signal, and a sector antenna is used for transmitting and receiving other signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and apparatus for transmitting and receiving radio signals.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram schematically showing a configuration example of a conventional radio transmitting / receiving apparatus. This configuration example is a case where the antenna is formed by a sector antenna having three sectors, and wireless signals are transmitted and received using the TDMA method.

In FIG. 1, reference numerals 42-1 to 42-3 denote three sectors of a sector antenna, and reference numeral 3 denotes an antenna selection switch connected to the first, second and third antenna sectors 42-1 to 42-3. (SW), 44 is a transmission / reception switch (TDD-SW), 45 is a receiver (RX), 46 is a demodulator (DEM), 47 is a transmitter (TX), 48 is a modulator (MOD), and 49 is a base. Band signal processing circuit (B
B) and 50 indicate transmission / reception control circuits, respectively. Further, A is a reception signal output, B is a transmission signal input, C is a timing control signal, D is a transmission / reception switching signal, and E is an antenna selection signal.

[0004] Using a conventional base station apparatus having such a configuration, a TDMA-TDD frame as shown in FIG.
That is, a signal (Ach) for broadcasting information, a plurality of signals (Cch) for exchanging radio channel control information between a specific terminal station (≧ 1) and a base station, and transmission / reception of data signals, respectively. A case where data signals are transmitted and received to and from a plurality of terminal stations in the wireless zone on a frame composed of a plurality of signals (Uch) to be performed will be described below.

Ach is a signal that broadcasts system information of the base station and must be transmitted uniformly to all areas covered by the base station. For this reason, the base station apparatus periodically transmits the Ach signal while sequentially switching the sector from the first sector 42-1 of the sector antenna to the second sector 42-2 and further to the third sector 42-3. . Since Cch is a signal for exchanging line control information with a specific terminal station, the Cch selects a sector in the direction in which the terminal station exists to transmit and receive a signal. If there are a plurality of terminal stations in the same direction as a certain sector, the plurality of terminal stations can be controlled by transmitting the same Cch downlink signal. The transmission and reception positions of Uch are controlled using Cch. The base station apparatus transmits and receives a signal from a certain terminal station by fixing an antenna to a certain sector. When transmitting the same signal to a plurality of terminal stations in different directions, the same signal is transmitted a plurality of times while selecting antenna sectors in each direction.

[0006]

The Ach signal is used for notifying system information to all the radio zones controlled by the radio base station and for each terminal station to establish frame synchronization using the Ach signal. Can be Transmission and reception of radio signals are performed at predetermined positions in a frame in which synchronization has been established.

However, according to the above-described conventional technique, when frame synchronization is lost due to a code error in a radio section or the like, an Ach signal can be received only once every sector number. There is a problem that the time until the synchronization is established becomes long.

Further, when another base station exists around the base station, according to the conventional technique, all signals are transmitted by selecting one of the sector antennas. There is also a problem that the probability that the station can detect the transmission signal from the present base station decreases, and the probability that the station receives interference of the transmission signal from the surrounding base stations increases.

The above problem can be solved by performing the radio channel control of the frame configuration shown in FIG. 5 with a single antenna that can cover all the zones. Will be received,
Multipath fading environment becomes severe. as a result,
The signal transmission characteristics are greatly deteriorated.

Accordingly, an object of the present invention is to solve the above-mentioned conventional problems and to provide a radio transmission / reception method and apparatus excellent in radio signal monitoring performance without deteriorating signal transmission characteristics.

[0011]

According to the present invention, there is provided a radio transmission / reception method using an omni-directional antenna for transmitting a broadcast signal and a sector antenna for transmitting / receiving other signals.

Further, according to the present invention, there is provided a radio transmission / reception apparatus for a radio base station for controlling transmission / reception of a radio signal in a radio zone, which transmits a signal to all radio zones covered by the radio base station. And a sector antenna for transmitting and receiving a radio signal in each area obtained by dividing a radio zone covered by the radio base station into a plurality of areas.

It is preferable that the one antenna is an omnidirectional antenna for transmitting a broadcast signal to all radio zones, and the sector antenna is an antenna for transmitting and receiving other signals.

[0014] By transmitting a signal, such as an Ach signal, on which broadcast is important by an antenna covering all zones,
The terminal station can receive the Ach signal for each frame. Therefore, even if frame synchronization is lost, synchronization acquisition can be started from the next frame, and Ach
Since the signal interval is short, the synchronization probability time can be reduced. Further, since the Ach signal of the neighboring base station can be easily detected, it is possible to prevent interference from other zones of the broadcast signal that is constantly transmitted. On the other hand, since the Cch signal and the Uch signal are signals transmitted and received between a specific terminal station and a base station, they are transmitted using a sector antenna. As a result, a signal for transmitting and receiving an actual signal can ensure the same line quality as that of the conventional technology.

It is preferable that the signal transmitted from the one antenna is a signal to which an error correction code having a higher error correction capability than a signal transmitted from a sector antenna is applied. When an antenna that can cover all zones is used, signal transmission characteristics due to multipath fading deteriorate. Also, since the purpose of the Ach signal is to notify information, the amount of information there is smaller than that of other signals. Therefore, an error correction code having a higher coding rate than the Cch signal and the Uch signal is applied to the Ach signal, and the deterioration due to multipath fading is compensated by the error correction.

[0016]

FIG. 1 is a block diagram schematically showing a configuration of an embodiment of the present invention. This embodiment is
An omni (omnidirectional) antenna is used for broadcast signals, and a three-sided sector antenna is used for communication with a specific terminal station.
This is an example of a case where communication is performed based on the frame configuration shown in FIG.

In FIG. 1, 11 is an omni (omnidirectional).
Antennas, 12-1 to 12-3 are three sectors of the sector antenna, 13 is an antenna selection switch (SW) connected to the first, second, and third antenna sectors 12-1 to 12-3, 14 Is a transmission / reception changeover switch (TDD-
SW), 15 is a receiver (RX), 16 is a demodulator (DE)
M), 17 is a transmitter (TX), 18 is a modulator (MO)
D) and 19 are baseband signal processing circuits (BB) and 20
Indicates transmission / reception control circuits. Further, A is a reception signal output, B is a transmission signal input, C is a timing control signal, D is a transmission / reception switching signal, and E is an antenna selection signal.

At a frame start timing, a system information signal is input as an input signal, and an Ach burst signal is generated via a baseband processing circuit 19. After that, the transmitter 17 side is selected by the transmission / reception changeover switch 14 and the omni antenna 11 is selected by the antenna selection switch 13, so that the Ach signal is transmitted uniformly to all the zones.

When transmitting and receiving the Cch signal and the Uch signal, the optimum antenna sector is determined by observing the radio signal between the base station and the terminal station in advance. The transmission / reception control circuit 20 determines an optimum antenna sector according to the terminal number of the communication partner given by the timing control signal and the transmission / reception mode.
And the transmission / reception switch 14 is switched. By performing this operation at the timing of each signal, transmission and reception of the Cch signal and the Uch signal are performed.

By transmitting a signal, such as an Ach signal, on which broadcast is important from the omni antenna 11 covering all zones, the terminal station can receive an Ach signal for each frame. Therefore, even when frame synchronization is lost, synchronization acquisition can be started from the next frame, and the interval between Ach signals is short, so that the synchronization probability time can be reduced. Further, since the Ach signal of the neighboring base station can be easily detected, it is possible to prevent interference from other zones of the broadcast signal that is constantly transmitted. On the other hand, the Cch signal and Uc
The h signal is a signal that is transmitted and received between a specific terminal station and a base station, and is thus transmitted using a sector antenna. As a result, the signal for transmitting and receiving the actual signal is
The same line quality as the conventional technology can be secured.

FIG. 2 is a block diagram schematically showing a configuration of another embodiment of the present invention, and FIG. 3 is a schematic diagram showing a configuration of a transmission processing unit of the baseband processing circuit shown in FIG. It is a block diagram. This embodiment is obtained by adding a function of selecting an error correction code to the embodiment of FIG.

In FIG. 2, 21 is an omni (omnidirectional).
Antennas 22-1 to 22-3 are three sectors of a sector antenna, 23 is an antenna selection switch (SW) connected to the first, second and third antenna sectors 22-1 to 22-3, 24 Is a transmission / reception changeover switch (TDD-
SW), 25 is a receiver (RX), 26 is a demodulator (DE)
M), 27 is a transmitter (TX), 28 is a modulator (MO)
D) and 29 denote baseband signal processing circuits (BB) each having a reception processing unit 291 and a transmission processing unit 292, and 30 denotes a transmission / reception control circuit. Further, A is a reception signal output, B is a transmission signal input, C is a timing control signal,
D is a transmission / reception switching signal, and E is an antenna selection signal.

Transmission processing section 2 of baseband processing circuit 29
Reference numeral 92 denotes a wireless header adding circuit (HE) as shown in FIG.
ADER addition 31, a selection switch (SW) 32, encoders (CODER) 33 and 34, and a CRC check bit addition circuit (CRC addition) 35.

In the present embodiment, when performing communication based on the frame configuration shown in FIG. 5, the control circuit 30 performs the same operation as the embodiment of FIG. Baseband processing circuit 2
The timing control signal is input to the transmission processing unit 292 of No. 9 and the selection switch 32 is controlled. As mentioned above,
The transmission processing unit 292 includes two encoders 33 and 3
4 are provided, and for example, a code having a higher error correction capability than the encoder 33 is prepared in the encoder 34. When the Ach signal is transmitted, the encoder 34 is selected by the selection switch 32 to perform encoding. When the Cch signal and the Uch signal are transmitted, the encoder 33 is selected and encoding is performed. And CRC for each signal
A check bit and a header are added and transmitted.

Omni antenna 2 capable of covering all zones
When 1 is used, signal transmission characteristics due to multipath fading deteriorate. Also, since the purpose of the Ach signal is to notify information, the amount of information there is smaller than that of other signals. Therefore, an error correction code having a higher coding rate than the Cch signal and the Uch signal is applied to the Ach signal, and the deterioration due to multipath fading is compensated by the error correction.

The embodiments described above are all illustrative of the present invention and not restrictive, and the present invention can be embodied in various other modified and modified forms. Therefore, the scope of the present invention is defined only by the appended claims and their equivalents.

[0027]

As described above in detail, according to the present invention, in a section for performing communication with a specific terminal station, transmission and reception are performed by selecting one antenna sector from among the sector antennas. When transmitting broadcast information, by performing transmission using an antenna that can transmit uniformly to all zones, it is possible to provide a wireless transmitting and receiving apparatus that is excellent in monitoring of wireless signals without deteriorating signal transmission characteristics. . Furthermore, since this can be realized by adding one terminal of the antenna selection switch of the conventional wireless transmission / reception device, there is an advantage that the device scale is hardly increased. Also, when transmitting a multicast signal using the wireless transmission / reception device of the present invention, the same signal is transmitted a plurality of times in the related art by transmitting the Uch signal in the same manner as the transmission of the Ach signal. On the other hand, a multicast signal can be transmitted in one transmission.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration of an embodiment of the present invention.

FIG. 2 is a block diagram schematically showing a configuration of another embodiment of the present invention.

FIG. 3 is a block diagram schematically showing a configuration of a transmission processing unit in the embodiment of FIG. 2;

FIG. 4 is a block diagram schematically showing a configuration of a conventional wireless transmitting / receiving apparatus.

FIG. 5 is a configuration example of a TDMA-TDD frame.

[Explanation of symbols]

11, 21 Non-directional antenna 12-1 to 12-3, 22-1 to 22-3 Antenna sector 13, 23 Antenna selection switch 14, 24 Transmission / reception switch 15, 25 Receiver 16, 26 Demodulator 17, 27 Transmission Modulators 18, 28 Modulators 19, 29 Baseband signal processing circuits 20, 30 Transmission / reception control circuits 291 Reception processing units 292 Transmission processing units 31 Radio header addition circuits 32 Selection switches 33, 34 Encoders 35 CRC check bit addition circuits A Reception Signal output B Transmission signal input C Timing control signal D Transmission / reception switching signal E Antenna selection signal

Claims (4)

[Claims] 1. A radio transmission / reception method using an omni-directional antenna for transmitting a broadcast signal and a sector antenna for transmitting / receiving other signals. 2. A wireless transmission / reception apparatus for a wireless base station for controlling transmission / reception of a wireless signal in a wireless zone, wherein one wireless transmission / reception apparatus for transmitting a signal to all wireless zones covered by the wireless base station. A wireless transmitting and receiving apparatus comprising: an antenna; and a sector antenna for transmitting and receiving a wireless signal in each area obtained by dividing a wireless zone covered by the wireless base station into a plurality of areas. 3. The signal according to claim 2, wherein the signal transmitted from the one antenna is a signal to which an error correction code having a higher error correction capability than a signal transmitted from the sector antenna is applied. Equipment. 4. The antenna according to claim 1, wherein the one antenna is an omnidirectional antenna for transmitting a broadcast signal to all wireless zones, and the sector antenna is an antenna for transmitting and receiving other signals. Item 4. The apparatus according to item 2 or 3.