JPS6038062B2 - Wireless communication method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wireless communication system used in a communication network consisting of a plurality of stations.

Conventionally, in wireless communication between multiple stations, a common frequency is provided for a master station and multiple slave stations, and the master station or slave stations call the necessary slave stations or master stations at any time to form a call line. There is a method in which the slave stations are treated as independent stations within the communication area of the master station, a frequency is assigned to each slave station, and a telephone line is formed between the slave stations and the master station.

In the former case, it is not possible for a slave station to always establish a call line with the current station, and each slave station operates at different times, which is similar to common mobile communications (taxi radio, etc.). An example of this can be seen in . In addition, in the latter case, the slave station can arbitrarily configure a communication line with the master station, and either the master station has a frequency corresponding to the slave station, or the master station uses one transmission frequency and multiplex modulation. By doing so, it becomes possible to construct a simultaneous communication line without crosstalk between slave stations. An example of this can be seen in mobile telephones (ship telephones, etc.). Furthermore, in selecting the frequency to be used (channel selection) for any of these methods, it is necessary to consider the channel spacing so that radio frequencies can be used effectively and there will be no mutual interference. In order to improve the quality of calls, frequency stability is usually required to be strict.

In order to satisfy these conditions, a highly stable crystal resonator is generally used as a frequency source, which inevitably increases the cost of the device. However, even in communication networks configured in this way, it may be necessary to change the frequency due to interference with other commercial radio frequencies, and in such cases, the change may be a few KHZ to several tens of KH2. Even if there were, it would be necessary to change the crystal oscillator that is the frequency source of both the master station and the slave station and readjust the frequency, which caused problems such as a large amount of cost and construction time. In order to solve these problems, the present invention sets the frequency so that the assigned frequency of the slave station is the sum of the frequency at which a unique proportional relationship is easily established between the frequencies of the master station and the frequency predetermined by the slave station. By configuring the frequency of the slave station to follow and automatically determine the frequency of the carrier wave transmitted from the master station, it is possible to eliminate the need for a crystal oscillator for each frequency and to change the frequency at the master station. The present invention provides a wireless communication system in which the frequency of a slave station is automatically changed by changing the frequency of the slave station.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a block diagram for explaining the principle of the present invention, and FIG. 2 is an embodiment of the present invention.

In FIG. 1, 1 is the master station, 2 is its transmitter, and 3 to
5 is a receiving unit corresponding to the slave station, 6 is a transmitting antenna, 7 is a receiving antenna, 8 is an antenna duplexer, and 9, 14
, 19 are slave stations, 10, 15, 20 are reception units of the slave stations, 11
, 16, 21 are transmitting units of the slave stations, 12, 17, 22 are receiving antennas of the slave stations, and 13, 18, 23 are transmitting antennas of the slave stations. Here, 〆o is the transmission frequency of the master station, and K,,
K2 and K3 are proportional constants specific to each slave station. Taking the slave station 9 as an example, it receives the carrier wave 〆o transmitted from the master station 1, performs frequency conversion using the proportionality constant K of the slave station 9 as described later, and sets K as the transmission frequency of the slave station 9. ,Nao
10's, is sent to the master station.Similarly, slave station 1 4,1
K2〆 at 9. Ju〆's2, K3 na. Transmission is performed using a transmission frequency of 10〆's3. On the other hand, when changing the frequency, if the transmission frequency ``o'' is set to ``o + △na'' in the master station 1, the slave station changes it to the same device, K(na. 10△〆)
is transmitted to the master station, and the frequency change is achieved by changing the frequency of the master station. In addition, "'s, 0 na's2,
〆's3 is a unique frequency predetermined for each of the slave stations 1, 2, and 3, and Na's is shown as a representative of Na's, , 〆's2, and Me's3. Next, an embodiment will be described with reference to FIG.

Here, {the master station is equipped with residual carrier modulation (VSB)
) shows an example using multiple modulation. 101 is a crystal oscillator of the nuclear power plant monkey, 102 is an oscillation circuit, 103 is a frequency divider, 104
1 is a multiplier, 105 is a modulation circuit, 106 is a frequency conversion circuit, 107 is an output amplification circuit, 108 and 109 are antennas, 1
10 is an amplifier circuit, 111 is a frequency conversion circuit, 112 is an intermediate frequency amplification circuit, and 113 is a demodulation circuit.

In the slave station shown in 'b', 114 is an antenna, 115 is an amplifier circuit, 116 is a carrier wave amplifier circuit, 117 is a frequency divider,
118 is a multiplier, 119 is a frequency conversion circuit, 12 is an intermediate frequency amplification circuit, 121 is a demodulation circuit, 122 is a crystal oscillator, 123 is an oscillation circuit, 124 is a modulation circuit, 125 is a frequency conversion circuit, 126 is an output An amplifier circuit, 127 is an antenna. Here, in the master station, the original oscillation frequency s produced by the crystal oscillator 101 is converted to (1/r) s by a frequency divider 103, and then converted to (p/r) s by a multiplier 104 through a modulation circuit 105. 〆s, the frequency is converted by the frequency conversion circuit 106, and (p/r-1) is set to ``amplifier circuit 10''.
V is supplied to the antenna 108 by 7. On the other hand, at the slave station, the carrier wave (p/
r-1) The amplifier circuit 115 amplifies the carrier wave, the carrier wave amplification circuit 116 extracts and amplifies the carrier wave, and the frequency divider 117
/n, multiplier 118 multiplies it by m to get m/n(p/r-1
) is frequency-converted by the input wave in the frequency converter 119 as 〆s, becomes an intermediate frequency 〆,F, which is amplified by the intermediate frequency amplification circuit 120 and demodulated by the demodulation circuit 121.

Here, main IF(p/r-1)(m/n-1)〆s. In the transmitting section of the slave station, the original oscillation of frequency 〆's by the crystal oscillator 122 is oscillated by the oscillation circuit 123, and after this is modulated by the modulation circuit 124, the output of the Liao multiplier 118 is used to convert the frequency to the frequency conversion circuit. The signal is frequency-converted by 125, amplified by an output amplification circuit 126, and supplied to an antenna 127.

At this time, the frequency becomes m/n(p/r-1)〆s+〆's. Again, the master station transmits the transmitted waves from the slave station to the antenna 109.
After receiving it at the transmitter 1 and amplifying it at the amplifier circuit 110,
The frequency is converted by the frequency conversion circuit 111 with the output of
〆s=〆,F, the intermediate frequency is amplified by the intermediate frequency amplification circuit 112, and demodulated by the demodulation circuit 113. Therefore, the transmission frequency of the master station is 〆.

=(p/r-1)〆s, the transmission frequency of this slave station is {m/n(p/r-1)〆s-〆's. When changing the frequency of the master station, change the original oscillation frequency 〆s + A〆s
When it is assumed that the transmission frequency of the master station is (p/r
-・)(MeS+△NaS)Ko(p/r-・)Nas+(p/
r-1) △〆s, and the above n. Ten△． Correspondence with na is na. =(p/r-1)〆s △Na=(p/r-1)△"
It becomes s. Here, the transmission frequency of the slave station is m/n (p/r
11) (Nas ten△Nas) tenna'8ko m/n (p/r-・
)NaS+mノn(p/r-1)△Nas+Na's=Kkuna. 10△na) 10〆′s. Therefore, the proportionality constant K is m/n. In addition, frequency dividers 103, 107, Liao multiplier 1
It goes without saying that 04, 1 18 can be easily constructed using a PLL.

Next, the frequency relationship of each part signal in the embodiment shown in FIG. 2 will be explained using one specific example.

P/r=20m/n=101/100, and the frequency of the slave station is Na's=1-999 MHz.The frequency of the crystal oscillator of the original master station is Na'S,=
2.000■MH2 If the frequency s2 of the crystal resonator of the master station after changing is set to 2-0001MHz, the master station transmission frequency, slave station transmission frequency, slave station intermediate frequency, and master station intermediate frequency are respectively The result will be as shown in the table below.

Therefore, the amount of change in the intermediate frequency of the slave station is 25 Hz, and the amount of change in the intermediate frequency of the master station is 75 Hz, and the change in intermediate frequency that determines the selectivity of the receiver can be almost ignored.

Furthermore, since there are few changes in the carrier wave, there is no need to retune the high frequency stage.

As explained above, according to the present invention, the transmission frequency of the slave station is controlled to follow the transmission frequency of the master station and is automatically determined, and the slave station does not have a separate oscillation source and is frequency-divided. There is an advantage that it is possible to transmit any frequency by adjusting the ratio and multiplication ratio.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram for explaining the principle of the invention, and FIG. 2 is a block diagram showing an embodiment of the invention.

1... Master station, 2... Transmitting section of the master station, 3
, 4, 5... Receiving section of the master station corresponding to the slave station, 6
......Main station's transmitting antenna, 7...Receiving antenna, 8
...Antenna duplexer, 9, 14, 19...Slave station,
10, 15, 20. ．． ．． ...Slave station receiving section, 11,1
6, 21...Slave station transmitter, 12, 17, 22
......Slave station reception antenna, 13, 18, 23...
...Slave station transmitting antenna, 101, 122...Crystal oscillator, 102,123...Oscillation circuit, 103,
117... Frequency divider, 104, 118...
・Multiplier, 105, 124...Modulation circuit, 10
6,119,125... Frequency conversion circuit, 10
7,126...Output amplification circuit, 108,109
, 127... antenna, 110, 115...
Amplification circuit, 111, 119... Frequency conversion circuit, 112, 120... Intermediate frequency amplification circuit, 1
13, 121... Demodulation circuit, 1 14...
...Antenna, 116...Carrier wave amplification circuit.

Tsutomu’ figure Figure 2

Claims (1)

[Claims] 1 In a communication network consisting of one master station and a plurality of slave stations, the carrier wave frequency assigned to each of the slave stations is obtained by multiplying the carrier wave frequency of the master station by a value that is a predetermined proportionality constant. and a frequency predetermined by the slave station, and the assigned carrier frequency of the slave station after changing the carrier frequency of the master station corresponds to the carrier frequency transmitted from the master station. A wireless communication system characterized in that it is configured as determined by: