JP2516139B2 - Millimeter-wave space diversity transmission / reception method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless LAN for wirelessly connecting a large number of child stations and a parent station in a room for communication.

[0002]

8 and 9 are block diagrams showing a conventional space diversity transmission / reception system of this type.
FIG. 8 shows a configuration example of reception space diversity when one wave of a transmission signal transmitted from a transmission side (not shown) through a single antenna is received at the reception side. 3 is an antenna switch (ANT SW) for switching these antennas 1 and 2, 4 is a receiver (REC) for converting an RF signal received by the antennas 1 and 2 into an intermediate frequency (IF) signal, and 5 is an IF receiver. A demodulator (DEM) 6 for demodulating the data signal converted into a signal is connected to the receiver 4 and the demodulator 5 and the antenna switch 3, and is a control circuit (CONT) for switching control of the antennas 1 and 2. is there.

In this conventional example, the RF signal from the antenna currently being received is converted into an IF signal by the receiver 4, and this IF signal is sent to the demodulator 5 and the control circuit 6 in the next stage. Further, the demodulated signal demodulated by the demodulator 5 is DATA
It is taken out as OUT and sent to the control circuit 6. When the control circuit 6 determines that there is no constant received power based on the IF signal from the receiver 4, and the demodulator 5
If it is determined that the code error rate of the demodulated signal is worse than the standard based on the demodulated signal from the antenna switch 3
Instruct to switch to another antenna. By doing so, a single receiver can selectively receive signals from two antennas.

Next, in the case of FIG. 9 as well, an example of the structure of the reception space diversity is shown. In this case, a method of simultaneously receiving signals with two antennas and selecting an antenna with a large reception level for communication is proposed. Given. That is, in the figure, the received signals from the antennas 7 and 8 are the receiver (R
EC1, REC2) 9 and 10, and the output signals from the respective receivers 9 and 10 are intermediate frequency signals (IF1
IF switch (IF)
SW) 11 is input. At the same time, the receivers 9 and 1
From 0 to the control circuit (CONT) 12, signals proportional to the received signal levels by the respective antennas 7 and 8 are input respectively, and as a result, the control circuit 12 receives the intermediate frequency signal (IF
The IF switch 11 is instructed to select the signal having the higher reception level of 1 OUT and IF2 OUT). The selected intermediate frequency signal is sent to the demodulator 13,
It is taken out as DATA OUT.

As described above, according to the space diversity system, even if the reception state or the reception sensitivity of one antenna is poor, the reception state or the reception sensitivity of the other antenna is relatively high by using the signal received by the other antenna. It can be improved.

The bidirectional communication performed in the millimeter wave band, which can transfer a large amount of data in a short time, is suitable for a wireless LAN which requires high speed data transmission.

[0007]

However, although the millimeter wave is suitable for high speed data transmission, the high speed of data transmission causes a large amount of multipath interference due to reflection in the room. Therefore, the communication path is switched by space diversity. However, it is not always possible to obtain a good reception state.

Further, assuming the diversion of a technique for performing millimeter-wave space diversity with the same structure as the conventional space diversity, the operation of the antenna switch can be switched at high speed based on the millimeter-wave band signal used as a carrier wave. It must be made. However, switching the antenna switch at high speed has a limitation in the performance of the element, and it is difficult to realize space diversity in the millimeter wave band with the switch configuration similar to the conventional one. That is,
High-speed data transmission cannot be realized simply by diverting millimeter waves to the space diversity transmission / reception system that has been conventionally used. Let me explain this point.

Generally, an equivalent circuit example is shown in FIG.
A PIN diode that can make the junction capacitance sufficiently small is used as a switch. However, in the millimeter wave band, the impedance change during conduction and non-conduction is reduced due to the influence of such parasitic capacitance and inductive reactance of the element, and therefore insertion loss and ON There is a problem that the off ratio characteristic is significantly deteriorated.

For example, as shown in FIG. 11, 5 sections, cutoff frequency 60 GHz, input / output impedance 50
Explaining the Ω LPF (band pass) type switch, the circuit constant of this LPF type switch is C1 = 0.04.
7PF, L1 = 0.166nH, C2 = 0.087P
F, L1 = 0.166 nH, C3 = 0.047 PF, and C1, C2, and C3 correspond to Cp of the PIN diode shown in FIG. In such an LPF type switch, since the cutoff frequency as the low pass filter needs to be set higher than the carrier wave, in the millimeter wave band, the series inductances L1 and L2 and the parallel capacitances C1 and C2,
There is a problem that the value of C3 becomes very small and it is difficult to realize.

Further, the series inductances L1 and L2 are obtained by bonding a wire having a thickness suitable for the chip electrode, but there is a problem that the length is limited by the chip size. Further, since the parallel capacitances C1, C2 and C3 are determined by the reactance of the switch as a diode, the cutoff frequency determined by the value must be sufficiently higher than the passing frequency.

Although the above example is of the lumped constant type, when it is difficult to realize the inductance, the distributed constant type can be considered as shown in FIGS. In this case, FIG.
As shown in Fig. 1, length l = λ / 4, characteristic impedance Z
o are connected in series, and PIN diodes are connected in parallel. FIG. 13 is an equivalent circuit thereof, Zd represents a PIN diode, and FIG. 14 is an equivalent circuit of the whole of FIG. In the case of this distributed constant type, the low-pass characteristic is not shown as shown in FIG. Therefore, when the value of the parallel capacitance C shown in FIG. 14 changes, the center frequency changes, which causes a problem in stabilizing the characteristics. Furthermore, if the change in impedance when the DC bias of the diode is conducting and when it is not conducting is small, the biggest problem is that the on / off ratio becomes small.To realize the space diversity method in the millimeter wave band, It is necessary to enable high-speed switching operation of the antenna.

If the conventional space diversity performed on the receiving side shown in FIG. 9 is applied, the millimeter wave switch is unnecessary, but the frequency of the received wave received by the antennas 7 and 8 is a single wave. In an indoor wireless LAN having a large number of reflection paths, multipath interference often occurs.

In view of the above-mentioned problems of the conventional space diversity system, the present invention provides a transmitting antenna on the transmitting side when high speed two-way communication by a millimeter wave is performed between a master station and a slave station by the space diversity transmitting / receiving method.
It is switched without using a switch in the millimeter wave band to hardly be subjected to multipath interference in a room reflection path is large, the provision of space diversity transmitting and receiving system having a frequency diversity effect that can transmit and receive in the millimeter wave band To aim .

[0015]

In order to achieve the above object, a millimeter wave space diversity transmission / reception system according to the present invention is used when a transmission characteristic of a transmission / reception signal is deteriorated between a large number of slave stations and a master station. , A wireless space diversity transmission / reception method in which a transmission path between currently transmitting / receiving antennas is switched to a propagation path between other antennas to perform two-way wireless communication, and the transmission side (for example, a master station) uses an intermediate frequency band. Of the upper sideband frequency component by mixing the intermediate frequency modulation means (for example modulator 22) for modulating the carrier wave of the carrier wave with the transmission data with the local oscillation signal of the millimeter waveband by the intermediate frequency signal sent from the intermediate frequency modulation means. And a lower sideband frequency component for transmitting frequency conversion means (for example, sideband separation / transmission switching means 23), and upper sideband separated by the transmission frequency conversion means. Sideband transmission means on the side bands of the wavenumber component obtained by mixing a carrier in the millimeter wave band to transmit from the first transmit antenna (e.g., a first antenna 26) (e.g.,
An upper sideband signal transmitter 24 and a duplexer 25),
A second transmission antenna in which the lower sideband obtained by mixing the lower sideband frequency components separated by the transmission frequency conversion means with a carrier in the millimeter waveband is different from the first transmission antenna in the disposition position ( For example, lower sideband transmitting means (for example, lower sideband signal transmitter 27) transmitting from the second antenna 29).
And the duplexer 28) and the output destination of the upper and lower sideband frequency components separated by the transmission frequency conversion means,
Based on the signal wave of the intermediate frequency band, the intermediate frequency signal selection switching means (for example, the sideband separation / delivery switching means 2) is selectively switched to the upper sideband transmitting means or the lower sideband transmitting means.
3), and the receiving side (for example, the slave station) receives the upper sideband or the lower sideband received from a single receiving antenna (for example, the antenna 35 of the slave station) as an intermediate frequency signal corresponding to the upper and lower sidebands. Upper and lower sideband receiving means (for example, the duplexer 36 and the receiver 37) for converting into the above, and received data demodulating means (demodulator 38) for demodulating the intermediate frequency signal sent by the upper and lower sideband receiving means. , It is assumed that wireless space diversity transmission / reception in the millimeter wave band is performed between the master station and the slave station.

[0016]

In the millimeter wave space diversity transmission / reception system (transmission diversity) according to the present invention , the upper sideband wave or the lower sideband wave including the transmission data is transmitted by the upper sideband transmission means and the lower sideband transmission means provided on the transmission side. It becomes possible to send. Further, the supply destination of the upper and lower sideband frequency components separated by the transmission frequency conversion means controls the switching operation of the intermediate frequency signal selection switching means based on the signal of the intermediate frequency band used by the intermediate frequency modulation means, and the upper and lower sidebands are controlled. Since the upper and lower sideband transmitting means, which is the destination of the wave, is mixed with the carrier wave, there is no need to use a millimeter waveband switch that is a carrier wave. Achieving obi space diversity.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a basic configuration of bidirectional communication between a master station and a slave station by a millimeter wave space diversity transmission / reception system according to the present invention. In the figure, transmission and reception by space diversity are performed between the master station, slave station 1 and slave station 2, and when the master station as the transmission side detects a parity error or the like from the transmission / reception signal, one of the currently transmitting The so-called transmission space diversity is possible in which the transmission side switches from the transmission means to the other transmission means for communication.

In the master station, 21 is a multiplexer (MUX) for inputting and multiplexing data, and 22 is an intermediate frequency modulating means for outputting a signal wave of an intermediate frequency band modulated by the input data from the multiplexer 21. The modulators (MODs) and 23 are controlled by a control circuit (CONT) 20 described later, and the input signal from the modulator 22 is mixed with a local oscillation signal in the millimeter wave band to generate an upper side band (USB).
As a transmission frequency conversion means for separating a frequency component and a lower sideband (LSB) frequency component, and an intermediate frequency signal selection switching means for switching and outputting an upper sideband frequency component and a lower sideband frequency component of an intermediate frequency signal. A functional sideband separation / transmission switching means (IF SW), 24 is an upper sideband signal transmitter (USB TX) for amplifying the above-mentioned upper sideband frequency component switched and output by the sideband separation / transmission switching means 23. , 25 are the upper sideband signal transmitters 24
A duplexer (DUP) that receives a transmission signal from the antenna (ANT) and transmits it via the next antenna (ANT), a first antenna (AN) that radiates a transmission signal including a signal component of an upper sideband.
T). In FIG. 1, the upper sideband signal transmitter 24 and the duplexer 25 cooperate to function as an upper sideband transmitting means for transmitting the upper sideband frequency component from the first antenna 26.

Further, 27 is a lower sideband signal transmitter (LSB TX) for amplifying the lower sideband (LSB) frequency component switched and transmitted by the sideband separating / transmitting switching means 23.
Reference numeral 28 is a duplexer for transmitting via the next antenna (ANT), and 29 is a second antenna (ANT) for radiating a transmission signal including a signal component of the lower sideband. In FIG. 1, the lower sideband signal transmitter 27 and the duplexer 2 are
8 cooperates to lower the second sideband frequency component to the second
It functions as a lower sideband transmitting means for transmitting from the antenna 29.

Further, 30 is a receiver (RX) for receiving an upper band wave or a lower band wave sent from the slave station 1 through the first antenna 26 and the duplexer 25 and converting it into an intermediate frequency signal, 31. Is a receiver (RX) that receives a signal transmitted from the slave station 1 via the second antenna 29 and the duplexer 28 and converts the signal into an intermediate frequency signal,
32 receives signals from the receivers 30 and 31 and is controlled by the control circuit 20 (reception switch operation control: R SW CONT) to receive the receivers 30 and 31.
, An intermediate frequency switch (IF SW) for switching and selecting one of the signals, a demodulator (DEM) 33 for demodulating the signal from the intermediate frequency switch 32, and a demultiplexer 34 for the output of the received data. Take out (RD
ATAOUT) demultiplexer (DMUX), 20 is the control circuit for controlling the sideband separation / transmission switching means 23 and the intermediate frequency switch 32.

Next, for example, in the slave station 1 (the same applies to the slave station 2, the description thereof will be omitted), 35 is an antenna as a receiving means for receiving the radio wave from the master station, 36 is a duplexer (DUP), and 37. Is a receiver (RX) that receives a transmission signal of the upper sideband (USB) or the lower sideband (LSB) from the master station via the antenna 35 and the duplexer 36 and converts the signal into an intermediate frequency signal (IF signal). , 38 are demodulators (DEM) for demodulating the IF signal from the receiver 37, 3
A demultiplexer 9 demultiplexes its output and extracts the data transmitted from the master station.

Further, 40 is a multiplexer for inputting (T DATA IN) data to be transmitted to the master station and multiplexing, 41 is a modulator (MOD) for outputting a signal wave of an intermediate frequency band modulated by this input signal, 42 Is this modulator 41
Is a transmitter (TX) that puts the signal from the carrier on a carrier wave and transmits the signal to the master station via the duplexer 36 and the antenna 35.

In the above basic configuration, for example, in the case of transmission space diversity for transmitting data from the master station side to the slave station side, the transmission data input through the multiplexer 21 in the modulator 22 is used as the carrier in the intermediate frequency band. Is modulated and transmitted to the sideband separation / transmission switching means 23. The sideband separation / transmission switching means 23 separates the modulated wave modulated by the modulator 22 into upper and lower sidebands and receives a transmission switching control signal from the control circuit 20 to determine whether the uppersideband or the lowersideband. Is transmitted, the circuit is switched to the antenna 26 side in the case of the upper sideband to send the upper sideband signal to the upper sideband signal transmitter 24, and in the case of the lower sideband, the antenna 29 is transmitted.
The circuit is switched to the side to send the lower sideband signal to the lower sideband signal transmitter 27. 1, the upper sideband signal transmitter 24, the lower sideband signal transmitter 27, the duplexer 2
5, the duplexer 28, the first antenna 26, and the second antenna 29 have equivalent functions, respectively, but the upper sideband signal is transmitted to the upper sideband signal transmitter 24 by the sideband separation / transmission switching means 23. Lower sideband to lower sideband signal transmitter 2
It is specified to the transmission function of each sideband because it is decided to send to each of the four.

Then, the signals input to the upper sideband signal transmitter 24 or the lower sideband signal transmitter 27 are input to the duplexer 25 and the first antenna 25 or the duplexer 28.
And the second antenna 29, respectively, to be transmitted to the slave station side. The switching by the intermediate frequency switch 32 is performed by monitoring the error of the data transmitted from the slave station and selecting a signal (upper sideband signal or lower sideband signal) having a good communication state. When 20 switches the intermediate frequency switch 32 (when the master station determines the signal selection by itself), the slave station requests or the upper and lower sidebands are sent to the slave station with the same data in a certain format. When the control circuit 20 sends a transmission switching signal to the intermediate frequency switch 32 so as to switch so that the one having a good communication state is selected and the one selected by the slave station is also selected by the master station (the reception state of the slave station. (When the master station selects and determines in association with the above), etc., the switching of the first transmitting unit or the second transmitting unit on the transmitting side may be appropriately processed by a predetermined communication protocol.

As described above, in the transmission space diversity according to the millimeter wave space diversity transmission / reception method according to the present invention, the upper sideband signal transmitter 24 functioning as the upper sideband transmission means provided in the master station as the transmission side. The upper sideband including the transmission data can be transmitted by the duplexer 25 and the first antenna 26, and the transmission data can be transmitted by the lower sideband signal transmitter 27, the duplexer 28, and the second antenna 29 that function as the lower sideband transmitting means. It becomes possible to transmit the lower sideband including the lower sideband.

Further, for switching the antennas, the sideband wave separation / selection means as the intermediate frequency signal selection switching means is based on the signal in the intermediate frequency band used by the intermediate frequency modulating means without using the switch in the millimeter waveband as a carrier wave. Since the control circuit 20 controls the switching operation of the transmission switching means 23, space diversity in the millimeter wave band can be realized without impairing the ON / OFF ratio characteristic in switching. Therefore, even in space diversity in the millimeter wave band, it is not necessary to use an expensive and high power consuming ultra-high speed switching element,
Since the intermediate frequency signal selection switching means can be constituted by a PIN diode or the like which is generally used in the conventional space diversity, there is no significant increase in cost and power consumption during system driving.

In order to transmit the upper sideband or the lower sideband which can obtain a good communication state from the transmission / reception state in the radio communication, the sideband separation / transmission switching means 23 is used to transmit the upper sideband signal transmitter 24 or the lower sideband signal. Sideband signal transmitter 27
Since the millimeter wave space diversity is performed between the master station and the slave station by selectively switching between, the transmission signal using the upper sideband is different from the conventional transmission space diversity method that transmits the same signal from different antennas. Depending on the difference in the propagation characteristics between the transmission signal using the lower sideband and the transmission signal using the lower sideband, the reception state will be good or bad. Therefore, by switching the first antenna 26 and the second antenna 29 in the master station on the transmitting side, the transmission path of the transmission signal can be changed and the transmission frequency can be changed, and the same effect as frequency diversity can be obtained. Therefore, it is possible to reduce multipath interference due to the reflection path in the room and increase the degree of freedom in installing the antenna.

Therefore, when transmitting and receiving in a millimeter-wave band wireless LAN with high directivity and high receiving sensitivity and high-speed transmission, the influence of fading due to multipath interference can be reduced, and a better reception state can be secured. Can be realized. Further, since the configuration is performed by the super heterodyne method using the frequency converter, not only the sideband signal obtained by amplitude-modulating the transmission carrier wave, but also the sideband wave of two waves having different frequencies is performed. Therefore, not only the amplitude modulation method,
There is also an advantage that it can be applied to various modulation methods such as a frequency modulation method and a phase modulation method.

Next, the case of realizing the transmission space diversity by the millimeter-wave space diversity transmitting and receiving system according to the present invention, specific examples of the sideband separation and transmitting switching means 23 will be described. 2 and 3 are detailed block diagrams of some functions on the transmission side.
In particular, FIG. 2 shows a configuration in which the upper sideband (USB) transmission signal is transmitted from the antenna 1 and the lower sideband (LSB) transmission signal is transmitted from the antenna 2, and FIG. 3 shows the upper sideband transmission signal. From the antenna 2 in the figure, the lower sideband transmission signal is transmitted to the antenna 1
2 shows a configuration for transmitting from.

In FIG. 2, 22 is a modulator (IF MOD) as in FIG. 1, and 23 'is an intermediate frequency switch (IF MOD).
SW). Further, 51 is the above antenna (ANT)
1, 52 is the antenna (ANT) 2, 53 is a local oscillator (LOC OSC) for generating signals in the millimeter wave band, 54
Is a transmission balance mixer (SB MIX 1) that mixes the intermediate frequency signal switched and transmitted by the intermediate frequency switch 32 and the millimeter wave from the local oscillator 53 to generate a sideband.
Similarly, 55 is switched by the intermediate frequency switch 23 ', but the intermediate frequency signal whose phase is shifted by 90 ° with respect to the above case is mixed with the millimeter wave from the local oscillator 53 to shift the phase by 90 °. Transmission balance mixer (S
B MIX 2) and 56 are connected to the local oscillator 53 and the transmission balance mixers 54 and 55 to transmit the millimeter wave signal from the local oscillator 53 without phase shift.
3 dB 0 ° hybrid to be transferred to 4, 55, 57 phase shifts the intermediate frequency signal from the intermediate frequency switch 32 by 90 ° with respect to the transmission balance mixer 55 side, and transmission balance without phase shift with respect to the transmission balance mixer 54 side. A 3 dB 90 ° hybrid that transfers to mixers 54 and 55, 58 is connected to transmission balance mixers 54 and 55 and antennas 52 and 51, and transmission balance mixer 5
It is a 3 dB 90 ° hybrid in which carrier waves mixed with intermediate frequency signals from 4, 55 are phase-shifted by 90 ° and sent to antennas 52, 51. In this embodiment, the intermediate frequency switch 23 ', the local oscillator 53, the transmission balance mixers 54 and 55, and the 3 dB 0 ° hybrid 5 are used.
6, the 3 dB 90 ° hybrid 57 and the 3 dB 90 ° hybrid 58 cooperate to embody the function of the sideband separation / transmission switching means 23 in FIG.

Similarly, in FIG. 3, except for the 3 dB 90 ° hybrid 59, it is exactly the same as the case of FIG. 2, and the hybrid 59 has the phase shift from the intermediate frequency switch 23 'reversed in the upper sideband and the lower sideband. Is. That is,
In the present embodiment, the intermediate frequency switch 23 ', the local oscillator 53, the transmission balance mixers 54, 55, 3 dB 0 °.
Hybrid 56, 3 dB 90 ° Hybrid 59, 3
By the cooperation of the dB90 ° hybrid 58,
It is intended to embody the function of the sideband separation / transmission switching means 23 in FIG. 2 and 3, the millimeter wave (LOC) phase from the local oscillator 53, the upper sideband (USB, fL0 + IF) phase, the lower sideband (LSB, fL0-IF) phase, The symbols are shown differently.

In the embodiment constructed as described above,
The intermediate frequency signal modulated by the transmission data in the modulator 22 is sent to the intermediate frequency switch 23 ', and the intermediate frequency switch 23' outputs the control signal (S) from the control circuit 20 shown in FIG.
W CONT) to shift the phase of the intermediate frequency signal from the modulator 22 by 0 ° or 90 °, and the intermediate frequency signal with a phase shift of 0 ° is transferred to the transmission balance mixer 54.
Those of 90 ° are sent to the transmission balance mixer 55. Upon receiving the above intermediate frequency signals, the transmission balance mixers 54 and 55 mix these signals with the millimeter wave transmitted from the local oscillator 53 via the 0 ° hybrid 56 to generate upper and lower sideband signals, respectively. The sideband signal is sent to the 90 ° hybrid 58.

USB passing through 90 ° hybrid 58
Is transmitted from the antenna 51 and the LSB is transmitted from 52 to the slave stations. The phase relationship between the upper and lower sideband signals in the antennas 51 and 52 at this time is as shown in the figure. FIG.
The same applies to the case of, and when the intermediate frequency switch 32 is switched to input to the input terminal “8” of the 90 ° hybrid 57, the LSB is from the antenna 51 and the US is from the antenna 52.
B will be transmitted respectively.

FIG. 4 is a block diagram showing an embodiment on the receiving side when the space diversity system is adopted on the transmitting side as shown in FIGS. In this case, one antenna selectively receives one of the upper and lower sidebands.

In the figure, 61 is an antenna for selectively receiving the upper sideband and the lower sideband of the transmission signal sent from the transmitting side according to the switching in the IFSW shown later, and 62 is the received signal from this antenna 61. The phase of 9
A 3 dB 90 ° hybrid (3 dB 90 ° HYB) that is shifted by 0 ° and distributed, 63 is a reception local oscillator (R LOC) that generates a carrier wave for converting a reception signal from the 3 dB 90 ° hybrid 62 into an intermediate frequency signal,
Reference numerals 64 and 65 respectively denote a reception balance mixer (R MI) for mixing a carrier wave from the local oscillator 63 and a reception signal from the 3 dB 90 ° hybrid and converting the mixture into an intermediate frequency signal.
X 1, R MIX 2), 66 is a 3 dB 90 ° hybrid (3 dB 90 ° HY) that shifts the intermediate frequency signals from the reception balance mixers 64, 65 by 90 °.
B) and 67 are controlled by a control signal (intermediate frequency switch switching signal) from a control circuit (not shown).
An intermediate frequency switch (IF) for connecting the 0 ° hybrid 66 to the terminal of FIG. 2 to pass the upper sideband of the received signal or to the terminal of 1 to pass the lower sideband.
SW) and 68 are intermediate frequency band demodulators (IF D) that demodulate the signal from the intermediate frequency switch 67 and provide an output signal.
EM). The phase of the signal at each part is as shown in the figure.

Since the phase of the data signal is opposite between the USB reception and the LSB reception, the phase of the output signal is inverted and output to the intermediate frequency band demodulator 68 in the case of LSB reception, for example. The function may be added in advance, or an inverting circuit may be separately provided and the intermediate frequency band demodulator 68 may be configured to supply only the data signal in the case of LSB reception to the inverting circuit. The output destination may be switched according to the above.

In the present embodiment configured as described above, the transmission signal sent from the transmission side shown in FIGS. 2 and 3 is phase-shifted by 90 ° by the 3 dB 90 ° hybrid 62 and the reception balance mixer 64, The signal is sent to the H.B.65, is mixed with the carrier wave from the receiving local oscillator 63 and becomes an intermediate frequency signal, and is sent to the 3 dB 90 ° hybrid 66. The intermediate frequency signal from the 90 ° hybrid 66 is selected by the intermediate frequency switch 67 from one of the upper and lower sidebands as described above, and demodulated by the intermediate frequency band demodulator 68 to take out data.

According to the present invention described above, the space
But performs a Iba City, then, an example employing a space diversity scheme at the receiving side will be described with reference to FIGS. 5-7. FIG. 5 is a block diagram showing the configuration of the transmitting side when the receiving side performs space diversity,
FIG. 6 is a block diagram showing the configuration of the receiving side including the master station which is the transmitting side at that time, and FIG. 7 shows a case where the upper and lower sidebands are selectively received by two antennas.
3 is a block diagram for explaining the configuration on the receiving side of the device from different angles. FIG.

In FIG. 5, reference numeral 71 is a local oscillator (LOCOSC) for generating a local oscillation signal in the millimeter wave band, and 72 is an intermediate frequency modulator (IF MOD) as an intermediate frequency modulating means for modulating an intermediate frequency signal with transmission data. , 73 is a transmission balance mixer (SB MIX) as a carrier mixing means for taking in the millimeter wave from the local oscillator 71 and the intermediate frequency signal from the intermediate frequency modulator 72 and outputting the transmission signal with a 90 ° phase shift, and 74 is this An antenna (ANT) as upper and lower sideband transmitting means for transmitting a transmission signal. In this embodiment, the transmission signal including the signal components of the upper and lower sidebands is output from the single antenna 74. However, similar to the above-described embodiment, the upper sideband transmitting means (for example, the upper sideband) is used. The upper and lower sideband transmitting means may be configured by the lower band sideband transmitting means (lower sideband signal transmitting means and second antenna) and the lower sideband transmitting means.

Further, in FIG. 6, the transmission circuit configuration of the master station shown in FIG. 5 (local oscillator 71, intermediate frequency modulator 7)
2. The transmission balance mixer 73 is a transceiver (master station TR)
X) 81, and is configured to perform bidirectional communication with the slave station via the antenna 82. In addition,
The antenna 82 may have a configuration in which a plurality of antennas (ANT) 74 of FIG. 5 are provided depending on the slave station.

In the slave station on the receiving side in FIG. 6, reference numeral 83 is a first antenna (ANT1) for selectively receiving the upper sideband (USB) frequency component of the transmission wave transmitted from the transmission side,
Reference numeral 84 is an antenna (ANT2) for selectively receiving the lower sideband (LSB) frequency component sent from the transmitting side, 8
Reference numerals 5 and 86 are duplexers, and reference numerals 87 and 88 are upper sideband receivers (USB RX) and similar lower sideband receivers (LSB RX) that selectively receive signals received from the duplexers 85 and convert the signals into intermediate frequency signals. ). Further, in the present embodiment, the upper sideband receiving means is constituted by the first antenna 83, the duplexer 86 and the upper sideband receiver 87, and the upper sideband receiving means is constituted by the second antenna 84, the duplexer 87 and the lower sideband receiving means 88. It constitutes the sideband receiving means.

Further, 89 is an upper and lower sideband receiver 87, 8
An intermediate frequency switch (IFSW) as an intermediate frequency signal selection switching means for switching the intermediate frequency signal from 8 and 90 as an intermediate frequency demodulating means for demodulating the signal from the intermediate frequency switch 89 and outputting data (DATA OUT). The demodulator (DEM) 91 receives the data (DAT
A IN) Transmission switch (T SW) for selecting transmission,
Reference numerals 92 and 93 are transmitters (USB TX, LSB) that are connected to the transmission switch 91 and the duplexers 85 and 86, respectively, and perform transmission processing on the upper sideband and the lower sideband.
TX) and 94 are control circuits for controlling the operations of the intermediate frequency switch 89 and the transmission switch 91. It should be noted that in the present embodiment, the demodulator 9 converts the received signal in a good communication state.
The control circuit 94 includes communication control means for controlling the switching operation of the intermediate frequency switch 89 based on the signal in the intermediate frequency band so as to supply 0 to 0.

Further, in FIG. 7, 101 and 102 are the receiving side antennas 83 and 84 of FIG. 6, respectively,
Reference numerals 103, 104 and 105 denote a reception balance mixer (R MIX 1, RMIX 2) and a reception local oscillator included in the upper sideband receiver (USB RX) 88 of FIG. 6, respectively. Reference numerals 106 and 107 denote an upper sideband bandpass filter and a lower sideband bandpass filter, respectively.
08 is a switching control (SW C
ONT) intermediate frequency switch (IF SW) 89,
Reference numeral 109 is an intermediate frequency gain adjustment circuit (IF AGC) for adjusting the gain of the intermediate frequency, and 110 is the same demodulator (IFDEM) as the intermediate frequency band demodulator (DEM) 90 of FIG.

In the reception space diversity according to the millimeter wave space diversity transmission / reception system as described above, the upper and lower sidebands including the transmission data are transmitted from the antenna 82 of the master station which is the transmission side, and the first antenna 83 and the first antenna 83 of the reception side are also used. The upper sideband wave and the lower sideband wave can be received by the two-antenna 84, and can be converted into an intermediate frequency signal by the upper sideband receiver 87 and the lower sideband receiver 88. Further, since the control circuit 94 controls the switching operation of the intermediate frequency switch 89 based on the signal of the intermediate frequency band used at the time of converting the intermediate frequency of the received wave without using the switch of the millimeter wave band which is the carrier wave, the intermediate frequency switch concerned. The on / off ratio characteristic of 89 does not deteriorate and the switching function is not impaired.

Therefore, the control circuit 94 controls to supply to the demodulator 90 the received signal in good communication state, which is either the intermediate frequency signal obtained from the upper sideband or the intermediate frequency signal obtained from the lower sideband. Thus, it becomes possible to perform millimeter wave space diversity between the master station and the slave station. As a result, similar to the transmission space diversity described above, it is possible to obtain the effect of frequency diversity, so it is difficult to be affected by fading due to multipath interference, and a space diversity transmission / reception method that can secure a good communication state should be used. You can

[0047]

As described in the foregoing, in the millimeter-wave space diversity transmitting and receiving system according to the present invention, the sideband transmission means and the lower sideband transmission means on which is provided on the transmitting side, above containing transmission data sidebands Alternatively, it becomes possible to transmit the lower sideband. Further, the switching operation of the intermediate frequency signal selection switching means is controlled based on the upper sideband frequency component or the lower sideband frequency component separated by the transmission frequency converting means, based on the signal of the intermediate frequency band used by the intermediate frequency modulating means. Therefore, it is not necessary to use a millimeter-wave band switch as a carrier for switching the output destination, and millimeter-wave band space diversity can be realized without impairing the on / off ratio characteristic in switching.

Therefore, the upper sideband transmitting means or the lower sideband transmitting means is selectively switched so as to transmit the upper sideband or the lower sideband capable of obtaining a good communication state from the transmission / reception state in the radio communication, It becomes possible to perform millimeter wave space diversity between the master station and the slave station. This makes it possible to transmit signal waves having different frequencies by switching the transmitting means on the transmitting side, and it is possible to obtain the effect of frequency diversity.

[0049] Thus, the millimeter-wave space diversity transmitting and receiving system which has the effect of frequency diversity can also ensure good communication state for a number of communication path through interference of the transmitted wave generated by the reflection of such interior wall and ceiling wall Therefore, it is possible to increase the degree of freedom in determining the position of the antenna.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a millimeter wave space diversity transmitter / receiver according to the present invention.

FIG. 2 is a block diagram showing a specific embodiment of the present invention when a space diversity system is adopted on the transmitting side.

FIG. 3 is a similar block diagram.

FIG. 4 is a block diagram showing an embodiment of a receiving side when the space diversity system is adopted on the transmitting side as shown in FIGS. 2 and 3.

FIG. 5 is a block diagram showing a configuration of a transmission side when a space diversity system is adopted on the reception side.

6 is a block diagram showing a configuration of the receiving side, including a master station having transmission circuits in the case of FIG.

FIG. 7 is a block diagram when the configuration of the receiving side of FIG. 6 is viewed from different angles in the case where upper and lower sidebands are selectively received by two antennas.

FIG. 8 is a block diagram showing an outline of a first conventional receiving method for space diversity.

FIG. 9 is a block diagram showing an outline of a second conventional receiving method of space diversity.

FIG. 10 is a circuit diagram showing an equivalent circuit of a PIN diode.

FIG. 11 is a configuration diagram of an LPF type switch.

FIG. 12 is a switch configuration diagram of a distributed constant type filter.

13 is a configuration diagram equivalent to the PIN diode section in the configuration diagram of FIG.

FIG. 14 is an equivalent circuit diagram of the entire FIG.

[Explanation of symbols]

 22 Modulator (MOD) 23 Intermediate Frequency Switch (IFSW) 24 Upper Sideband Signal Transmitter (USB TX) 26 Master Station Antenna (ANT) 27 Lower Sideband Signal Receiver (LSB TX) 29 Antenna (ANT) 30 Reception Machine (RX) 31 receiver (RX) 32 intermediate frequency switch 33 demodulator 35 slave station antenna 37 receiver 41 modulator 42 transmitter (TX)

Claims (1)

(57) [Claims] 1. When a transmission characteristic of a transmission / reception signal is deteriorated between a large number of slave stations and a master station, the transmission path between the transmission / reception antennas currently in communication is switched to a propagation path between other antennas to perform bidirectional communication. In the wireless space diversity transmission / reception method for performing the wireless communication of, the transmitting side transmits the intermediate frequency modulating means for modulating the carrier of the intermediate frequency band with the signal of the transmission data, and the intermediate frequency signal transmitted from the intermediate frequency modulating means. A transmission frequency conversion unit that separates an upper sideband frequency component and a lower sideband frequency component by mixing with a local oscillation signal in the millimeter waveband, and an upper sideband frequency component separated by the transmission frequency conversion unit. The upper sideband transmitting means for transmitting from the transmitting antenna and the lower sideband frequency component separated by the transmitting frequency converting means are arranged at different positions from the first transmitting antenna. The lower sideband transmitting means for transmitting from the second transmitting antenna and the output destination of the upper and lower sideband frequency components separated by the transmitting frequency converting means are transmitted by the upper sideband based on the signal wave of the intermediate frequency band. Means or a lower sideband transmitting means for selectively switching to an intermediate frequency signal selection switching means, and the receiving side responds to the upper sideband or the lower sideband with the upper sideband or the lower sideband received from a single receiving antenna. An upper and lower sideband receiving means for converting to an intermediate frequency signal, and a receiving data demodulating means for demodulating the intermediate frequency signal sent by the upper and lower sideband receiving means are provided at least, and the millimeter wave between the master station and the slave station. A millimeter-wave space diversity transmission / reception method characterized by performing wireless space diversity transmission / reception in a band.