JP2001077778A - Frequency arraying method and its communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the transmission/reception separation degree of transmitting frequency two waves and receiving frequency two waves by assigning a transmission frequency and a receiving frequency to bands which are not adjacent to each other and setting two transmitting frequencies which are to be used in single equipment to be at a distance equal to or larger than the specific multiple of a transmission signal band from each other. SOLUTION: In a series of communication equipment 21 to 29 to be used for a communication line for executing fully duplex communications while executing relay transmission, an available frequency band is divided into proper widths, a channel frequency is set to each of this band, and a transmitting frequency and a receiving frequency are assigned to the channel frequency of the bands after division, which are different from each other. Two transmitting frequencies to be used in a single device are set with a distance, which is equal to or larger than two-fold, e.g., three-fold, from each other. Then, when a series of communication equipment 21 to 29 executing relay transmission repeatedly use limited frequencies, an interval between the series of communication equipment which comes to generate unnecessary waves to exert influence to each other because of using the same frequency is maximized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency arranging method for arranging frequencies in communication including full-duplex communication for effective use including frequency reuse and for reducing interference between transmission and reception. It relates to the communication device.

[0002]

2. Description of the Related Art In a communication device having a function of performing full-duplex communication and transmitting data having a transmission signal bandwidth of 3 MHz while relaying it repeatedly, two sets of transceivers are provided in one communication device. Have. Although the frequencies used in these transceivers need to be different from each other, the usable frequency band is limited, and the frequencies in this frequency band are used repeatedly.

[0003]

In order to ensure the quality of communication, both the transmitter and the receiver use a band-pass filter having a transmission signal bandwidth as a communication band at an intermediate frequency stage. Therefore, in order to prevent the two transmission frequencies from interfering with each other, the frequency difference is about twice or more of the transmission signal bandwidth.
The frequency difference of 6 MHz or more, which is a frequency difference of about 2 times or more of the transmission signal bandwidth, and the transmission at the output stage is performed by the characteristics of the band-pass filter at the output stage. It is a problem to improve the transmission / reception separation by taking a frequency difference so that the frequency wraparound does not affect the reception frequency.

Further, a communication device arranged to form a relay relay transmission system has to reuse a transmission frequency and a reception frequency, and can reduce the influence of unnecessary waves generated in the reuse. It is an issue.

[0005]

In order to solve the above-mentioned problems, the invention according to claim 1 comprises two sets of a transmitter and a receiver, two transmission frequencies of the transmitter and reception of the receiver. A frequency arrangement method applied to a communication device that performs relay relay transmission using two frequencies, wherein a frequency band usable in the communication device is divided into four bands, and a transmission signal bandwidth is divided into the four bands. A channel frequency as a width is set, and two bands that are not adjacent to each other are selected, and the two transmission frequencies are set to any one of the channel frequencies in one of the bands, and the interval is set to the transmission signal band. And assigning the two reception frequencies to any one of the channel frequencies in the other one of the bands such that the interval is at least twice the transmission signal bandwidth. Attached A plurality of the communication devices using the allocated four channel frequencies are arranged so as to form a relay relay transmission system, and the communication devices using the same channel frequency which influences each other as unnecessary waves are provided. The channel frequencies are arranged so as to be spaced apart.

[0006] The invention according to claim 2 is that, of the two transmission frequencies and the two reception frequencies, one transmission frequency is used for an uplink and another one of the transmission frequencies is used for a downlink. The channel frequencies are arranged such that one wave of the reception frequency is used for an uplink and one wave of the reception frequency is used for a downlink.

Further, according to a third aspect of the present invention, a frequency band usable in the communication device is divided into four bands by four types of bandpass filters having different passband frequencies.

Further, according to a fourth aspect of the present invention, in the four kinds of band-pass filters, the ends of the respective 3 dB attenuation bandwidths overlap.

Further, according to a fifth aspect of the present invention, a frequency band usable in the communication device is divided into a plurality of bands excluding four.

Further, in the invention according to claim 6, the channel frequency is set in a width other than the transmission signal bandwidth in the four divided bands.

Further, according to the present invention, a relay relay transmission system is formed by using two non-adjacent bands among the four divided bands, and by using the other two non-adjacent bands. By forming another relay relay transmission system, two relay relay transmission systems that do not need to consider frequency interference with each other are formed.

Further, in the invention according to claim 8, the relay relay transmission system is formed in a plane by alternately arranging the two relay relay transmission systems.

A ninth aspect of the present invention is a communication device comprising two sets of a transmitter and a receiver, and relay-relaying the two transmission frequencies of the transmitter and the two reception frequencies of the receiver. Then, the usable frequency band in the communication device is divided into four bands, a channel frequency having a width of a transmission signal bandwidth is set in the four bands, and two bands not adjacent to each other are selected. And allocating the two transmission frequencies to any one of the channel frequencies in one of the bands so that the interval is twice or more the transmission signal bandwidth, and Allocating the two reception frequencies to any one of the channel frequencies so that the interval is at least twice the transmission signal bandwidth, and passing the band including the allocated channel frequency. Includes two kinds of band-pass filter, to relays relay transmission using the channel frequency 4 wave assigned.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention divides a usable frequency band into a band of an appropriate width in a communication device used for a communication line performing full-duplex communication (two-way simultaneous communication) while performing relay relay transmission. When the channel frequency is set in this band, the transmission frequency and the reception frequency are assigned to the channel frequencies of the divided bands different from each other, and when the channel frequency is represented on a frequency line, the interval between the respective channel frequencies is determined. Is equal to the transmission signal bandwidth transmitted by one frequency, so that the two transmission frequencies used in one device have an interval that causes interference with signals transmitted by adjacent frequencies. Are set to be separated from each other by three times the transmission signal bandwidth (if it is two times or more, the mutual interference characteristics can be reduced. Here, the distance is described as three times). In order to prevent mutual interference, and to use a limited frequency repeatedly in a series of communication devices performing relay relay transmission, unnecessary waves are generated to use the same frequency. Care is taken to prevent communication quality from deteriorating by maximizing the spacing between communication devices that will affect each other. (First
FIG. 1 shows a communication device arranged to form a relay relay transmission system and a frequency array applied to this communication device. Each of the communication devices 21 to 29 includes a transmitter and a receiver. For example, the communication device 21
Comprises an uplink transmitter 1, a downlink transmitter 2, a downlink receiver 3, and an uplink receiver 4, and the communication device 22 includes an uplink transmitter 5, a downlink transmitter 6, a downlink receiver 7, and an uplink receiver 8. Similarly, the communication devices 23 to 27 also include an uplink transmitter, a downlink transmitter, a downlink receiver, and an uplink receiver. The communication device 28 includes an uplink transmitter 9, a downlink transmitter 10, a downlink receiver 11, and an uplink receiver 12. Communication device 29
Comprises an uplink transmitter 13, a downlink transmitter, a downlink receiver 14, and an uplink receiver. With such a configuration, the uplink is relay-relay-transmitted from the communication device 29 to the communication device 21, and the downlink is relay-relay-transmitted from the communication device 21 to the communication device 29.

The downlink receiver 7 has a channel frequency fc6 as a reception frequency.
The channel frequency fc6, which is the transmission frequency from, is received as the key signal 15. On the other hand, the channel frequency fc6 which is the transmission frequency from the uplink transmitter 13 is the unnecessary wave 1
6 is received by the downlink receiver 7.

Further, when the channel frequencies having such an arrangement are repeatedly used as shown in FIG. 1, the intervals between the same channel frequencies appearing are made as large as possible so that the same channel frequencies become unnecessary waves. Therefore, it is possible to reduce the possibility that the communication quality is deteriorated due to interference.

FIG. 2 is an example of the setting of the channel frequency used in the frequency arrangement of FIG. Here, the usable frequency band lower limit value FL and the usable frequency band upper limit value F
The difference from U is a frequency band usable by the communication devices 21 to 29. An available frequency band is set to 100 MHz, and transmissions used by transmitters (uplink transmitter and downlink transmitter) and receivers (downlink receiver and uplink receiver) of communication devices 21 to 29 are used. The frequency and the receiving frequency are
The description will be made on the assumption that the transmission signal bandwidth is 3 MHz. In this case, approximately 22 MHz is set as a pass band, and 26 MHz is set as a 3 dB attenuation band, and divided into four bands by four types of band pass filters having different pass band frequencies. Passband 22MH
In the division by z, the A band pass bandwidth 35, the B band pass bandwidth 36, the C band pass bandwidth 37, and the D band pass bandwidth 3
8 and 4 are divided. This also results in a 3 dB attenuation band 26
In the division in MHz, the A band 3 dB attenuation bandwidth 31 and B
Band 3 dB attenuation bandwidth 32 and C band 3 dB attenuation bandwidth 3
3 and a D-band 3 dB attenuation bandwidth 34.

Channel frequencies fa1 to fa7 for A band pass bandwidth 35, channel frequencies fb1 to fb7 for B band pass bandwidth 36, channel frequencies fc1 to fc7 for C band pass bandwidth 37, and D band pass bandwidth. In 38, channel frequencies fd1 to fd7 are set. A band 3dB attenuation bandwidth 31, B band 3dB attenuation bandwidth 32,
C band 3dB attenuation bandwidth 33, D band 3dB attenuation bandwidth 34, A band pass bandwidth 35, B band pass bandwidth 36,
The relationship between the lower limit and the upper limit of the C band pass bandwidth 37 and the D band pass bandwidth 38 is as shown in FIG.

Now, if two transmission frequencies are allocated to the A-band pass bandwidth 35 which is the lowest frequency band,
The two reception frequencies are assigned to a C-band pass bandwidth 37, which is the third frequency band from the bottom, one space apart. This makes it possible to reduce interference between the transmission frequency and the reception frequency.

Each of the four bands (A band pass bandwidth 35, B band pass bandwidth 36, C band pass bandwidth 37, D band pass bandwidth 38) has a transmission signal bandwidth of 3 MHz. (The A-band pass bandwidth 35 includes channel frequencies fa1 to fa7,
Fb1 to fb7 for B band pass bandwidth 36, fc1 to fc7 for C band pass bandwidth 37, D band pass bandwidth 38
Are set to fd1 to fd7). Any two of these channel frequencies are arbitrarily combined to secure a bidirectional channel frequency. However, when adjacent channel frequencies are used, the edges of the transmission signal bandwidth overlap, and communication represented by an error rate is performed. The quality will be degraded. Therefore, by securing an interval at least three times the transmission signal bandwidth, seven channel frequencies can be used effectively.

Next, communication devices 21 to 29 used for realizing the frequency arrangement of the present invention will be described. The communication devices 21 to 29 have a frequency band that is not adjacent to each other among four frequency bands obtained by dividing a usable frequency band of 100 MHz using a band-pass filter (not shown) having a pass band of 22 MHz and a 3 dB down band of 26 MHz. It has two bandpass filters and is built for exclusive use for transmission and reception. It also has a band-pass filter that limits the transmission signal bandwidth at the intermediate frequency stage. The frequency is set by a synthesizer, and the intermediate frequency and the local oscillation frequency transmitted from the synthesizer are combined to form a transmission frequency, and the local transmission frequency transmitted by the synthesizer is subtracted from the reception frequency to obtain an intermediate frequency. (Operation of First Embodiment) The operation of the first embodiment will be described with reference to FIGS.

Now, the channel frequencies fc6, fc2, fc2,
Further, channel frequencies fa4 and fa7 are allocated as transmission frequencies used for the transmitter.

At this time, the receiving frequency is in the third C-band pass bandwidth 37 from the bottom. On the other hand, the transmission frequency is in the lowest A-band pass bandwidth 35. It is assumed that the input power of the received signal as the significant wave 15 is -80 dBm, and the sneak power of the transmission signal to the receiving side is 20 dBm. Since the receiving circuit includes a broadband low-noise amplifier, it is necessary to suppress the power level to a level equal to or lower than that of the received signal in order not to saturate the operation of the amplifier due to the wraparound of the transmitted signal. That is, it is necessary to suppress the sneak power of the transmission signal by 100 dB or more. It is extremely difficult and impractical to provide such suppression only by antenna isolation. In addition, it is possible to separate a specific frequency from other frequencies with a commonly used band-pass filter, but the operating frequency of the equipment is not always constant, and the frequency is reassigned each time it is used. In such a case, it faces an unrealistic problem that a large number of filters must be mounted and switched for use.

In order to solve such a problem, the usable frequency band is divided into four, and in order to sufficiently exhibit the characteristics of the band-pass filter, the divided bands which are not adjacent to each other are deliberately used. It will be used separately for sending and receiving. In the communication devices 21 to 29, about 10 dB is secured by securing 35 dB by a band-pass filter (not shown) and 65 dB by isolation of an antenna (not shown).
Suppression of 0 dB can be realized, and a low-noise amplifier (not shown) connected immediately below a band-pass filter of a receiving circuit (not shown) does not saturate due to a transmission signal sneaking into the receiving side. .

Next, in the above example, the two transmission frequencies are separated from each other by 9 MHz, and the reception frequencies are also separated from each other by 9 MHz. This frequency interval is determined by the communication device 21
29, which contributes to reducing the mutual interference characteristics of the channel frequencies used.

Due to the characteristics of the band-pass filter at the intermediate frequency stage, an attenuation of 20 dB or more can be realized at a distance of 2.2 MHz or more from the center frequency of the frequency.
If the channel frequencies adjacent to each other among the channel frequencies set at intervals of the transmission signal bandwidth of MHz are not used, they can be separated without causing frequency interference with each other. In other words, since they are separated by 9 MHz, two-way simultaneous communication is possible without causing mutual interference.

Further, the connections are sequentially made so as to maintain the above two relationships, and the channel frequencies are determined so that the same channel frequencies are used as far apart from each other as possible. Will be. In this case, the same channel frequency as the channel frequencies fa4 and fc6 used for the relay relay transmission between the communication device 21 and the communication device 22 appears again in the communication between the communication device 28 and the communication device 29. is there. Therefore, the communication device 21
The communication device 28 and the communication device 28 affect the channel frequency fa1 as an unnecessary wave, and the communication device 22 and the communication device 29 affect the channel frequency fc6 as the unnecessary wave 16. However, since the transmission distance between the significant wave 15 and the unnecessary wave 16 is 1: 7, the unnecessary wave 16 is attenuated by 17 dB with respect to the significant wave 15 in the power ratio. If this level of attenuation can be ensured, communication quality does not deteriorate.

Also, as an example, the usable frequency band has been described as 100 MHz, but if a wider frequency band can be secured, the number of channel frequencies that can be set in the divided frequency band increases, and In the case of re-use, the interval at which the same channel frequency appears can be widened, which is advantageous for the problem of communication quality deterioration due to mixing of unnecessary waves. On the other hand, if only a frequency band narrower than 100 MHz can be secured as an available frequency band, the interval between the two divided bands will be closer to each other. A frequency arrangement similar to the 100 MHz band can be realized.

In the above description, the usable frequency band is divided into four, but a similar frequency arrangement can be realized by division other than four. (Embodiment of the Second Invention) The frequency arrangement described above can be realized by using two of the four divided bands. Therefore, by using the remaining two bands in the same manner, it is possible to construct a relay relay transmission system of two streams that does not need to consider frequency interference with each other. By alternately arranging such two relay relay transmission systems, a communication system can be constructed in a planar manner.

[0030]

According to the present invention, the following effects can be obtained.

The usable frequency band is divided, the transmission frequency and the reception frequency are assigned to bands that are not adjacent to each other, and the channel frequencies arranged at intervals of the transmission signal bandwidth are repeatedly used under certain conditions. Thus, full-duplex communication (simultaneous two-way communication) can be realized by the relay relay transmission method without deteriorating the communication quality.

[Brief description of the drawings]

FIG. 1 illustrates a communication device arranged to form a relay relay transmission system and a frequency array applied to the communication device.

FIG. 2 is an example of setting a channel frequency used for the frequency arrangement of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Uplink transmitter 2 Downlink transmitter 3 Downlink receiver 4 Uplink receiver 5 Uplink transmitter 6 Downlink transmitter 7 Downlink receiver 8 Uplink receiver 9 Uplink Line transmitter 10 Downlink transmitter 11 Downlink receiver 12 Uplink receiver 13 Uplink transmitter 14 Downlink receiver 15 Significant wave 16 Unnecessary wave 21-29 Communication device 31 A band 3 dB Attenuation bandwidth 32 B-band 3 dB attenuation bandwidth 33 C-band 3 dB attenuation bandwidth 34 D-band 3 dB attenuation bandwidth 35 A-band pass bandwidth 36 B-band pass bandwidth 37 C-band pass bandwidth 38 D-band pass bandwidth

Claims (9)

[Claims] 1. A frequency arrangement method applied to a communication device that includes two sets of a transmitter and a receiver, and performs relay relay transmission using two transmission frequencies of the transmitter and two reception frequencies of the receiver. Dividing a frequency band usable in the communication device into four bands, setting a channel frequency having a width of a transmission signal bandwidth in the four bands, selecting two bands that are not adjacent to each other, Allocating the two transmission frequencies to any one of the channel frequencies in one of the bands so that the interval is at least twice the transmission signal bandwidth, and selecting one of the channel frequencies in the other one of the bands. The two reception frequencies are assigned to any one of the channel frequencies so that the interval is at least twice the transmission signal bandwidth, and the plurality of communications using the assigned four channel frequencies are performed. Arranging the devices so as to form a relay relay transmission system, and arranging the channel frequencies so that the communication devices that use the same channel frequency and affect each other as unwanted waves are spaced apart. The frequency arrangement method characterized by the above-mentioned. 2. The transmission frequency 2 wave and the reception frequency 2
Of the waves, one of the transmission frequencies is used for an uplink, another of the transmission frequencies is used for a downlink, one of the reception frequencies is used for an uplink, and one of the reception frequencies is used for an uplink.
2. The frequency arrangement method according to claim 1, wherein the channel frequencies are arranged so that waves are used for a downlink. 3. The frequency arrangement method according to claim 1, wherein a frequency band usable in said communication device is divided into four bands by four types of bandpass filters having different passband frequencies. 4. The four types of said band-pass filters,
4. The frequency arrangement method according to claim 3, wherein ends of the respective 3 dB attenuation bandwidths overlap. 5. The frequency arrangement method according to claim 1, wherein a frequency band usable in said communication device is divided into a plurality of bands excluding four. 6. The frequency arrangement method according to claim 1, wherein the channel frequency is set in a width other than the transmission signal bandwidth in the four divided bands. 7. A relay relay transmission system is formed using two non-adjacent bands among the four divided bands, and another relay relay transmission system is formed using the other two non-adjacent bands. 2. The frequency arrangement method according to claim 1, wherein two relay relay transmission systems that do not need to consider frequency interference with each other are formed by forming. 8. The frequency arrangement method according to claim 7, wherein said relay relay transmission system is formed in a plane by alternately arranging said two relay relay transmission systems. 9. A communication device comprising two sets of a transmitter and a receiver, and relay-relay-transmitting the two transmission frequencies of the transmitter and the two reception frequencies of the receiver. A possible frequency band is divided into four bands, a channel frequency having a width of a transmission signal bandwidth is set in the four bands, two bands not adjacent to each other are selected, and one of the bands is selected. Allocating the two transmission frequencies to any one of the channel frequencies in a band such that the interval is at least twice the transmission signal bandwidth, and any one of the channel frequencies in the other one of the bands And the two types of band-pass filters that pass the band including the allocated channel frequency are assigned to the two reception frequencies so that the interval is twice or more the transmission signal bandwidth. A communication device comprising: relay relay transmission using the allocated four channel frequencies.