JPH05199141A - Frequency converter and transmitter/receiver - Google Patents

Abstract

(57) [Summary] [Purpose] To enable sharing of terminals between communication systems with different bandwidths and frequency differences between the upper and lower lines. [Structure] There are first and second time division multiplex communication systems having different allocated bandwidths, and a terminal for the first communication system is connected or built in for use as a terminal for the second communication system. As the frequency conversion device 1, the reception mixed frequency is selected with respect to the predetermined frequency of the reception signal in the use band of the second communication method, and the mixed frequency at reception is set to the predetermined frequency of the reception signal in the use band of the first communication method. Further, the transmission signal in the use band of the second communication method is converted by selecting a transmission-time mixed frequency different from the reception-time mixed frequency for a predetermined frequency of the transmission signal in the use band of the first communication method. The frequency conversion device is configured to convert the predetermined frequency.

Description

Detailed Description of the Invention

[0001]

The present invention relates to TDMA (time division multiplexing).
The present invention relates to a frequency conversion device used corresponding to a communication system that employs a system and a transmission / reception device including the frequency conversion device.

[0002]

2. Description of the Related Art In recent years, mobile phone networks and mobile communication networks have been developed, and various communication networks are being put into practical use according to regions and uses. For example, there are digital cellular communication networks using the 800MHz band and digital cellular communication networks using the 1.5GHz band at the beginning of implementation in Japan, and in Europe, for example, PCNs for small mobile phones are used. (Parsonal communication networ
k) and GSM (group speci
almobil) etc. Of course, in addition to this, there are various communication networks for ships, airplanes, government offices, and commercial radios such as MCA.

[0003]

By the way, since these various communication networks have different frequency bands, transmission systems, etc., communication is usually performed by using a dedicated communication terminal (transmission / reception device) adapted to each system. It is done. Here, the above-mentioned 800 MHz band and 1.5 GHz band digital cellular communication networks, PCN and GSM, etc. have the same usage areas and applications, so in reality, both types of communication terminals can be shared. Is desirable.

However, since there is a difference in the used bandwidth and the frequency interval of each line of transmission / reception between these communication networks, simply using a frequency converter allows a transmission / reception device compatible with one system. There is a problem that it cannot be used also as a transmitter / receiver of the other system.

FIG. 5 shows the frequency bands used in each of the 800 MHz band and 1.5 GHz band digital cellular communication networks.
In the band digital cellular communication network, the 16MHz band from 810MHz to 826MHz is used as the downlink from the base station to the mobile terminal, and the 16MHz band from 940MHz to 956MHz is used from the mobile terminal to the base station. We use as line. The frequency difference between the uplink and the downlink is 130MHz.
(Besides metropolitan areas, 815MHz to 82
1 MHz and 945 MHz to 951 MHz of the uplink are not used. )

On the other hand, in the 1.5 GHz digital cellular communication network, a 12 MHz band from 1429 MHz to 1441 MHz and a 14 MHz band are used.
Both 12MHz band from 53MHz to 1465MHz are used as uplink from mobile terminal to base station,
12MHz band from MHz to 1489MHz and from 1501MHz
Both the 12MHz band up to 1513MHz are used as the downlink from the base station to the mobile terminal (that is, the uplink and the downlink each have a band of 24MHz, but each band is divided). The frequency difference between the uplink and the downlink
It is 48MHz. That is, there is a difference between these two communication systems in that the used frequency bandwidths of the upper and lower lines, the frequency difference between the upper and lower lines, and the relationship between the upper and lower frequencies and the upper and lower lines are opposite to each other.

FIG. 6 shows the frequency bands used by GSM and PCN. In GSM, the 25 MHz band from 890 MHz to 915 MHz is used as the uplink from the mobile terminal to the base station, and from 935 MHz. The 25MHz band up to 960MHz is used as the downlink from the base station to the mobile terminal. The frequency difference between the uplink and downlink is 45MHz.

On the other hand, in PCN, from 1710MHz to 1785MHz
Up to 75MHz band is used as the uplink from the mobile terminal to the base station, and from 1805MHz to 1880MHz.
The 75MHz band is used as the downlink from the base station to the mobile terminal. Frequency difference between the uplink and downlink is 95MH
z. That is, there is a difference in the frequency band used between the upper and lower lines and the frequency difference between the upper and lower lines between the two communication systems.

That is, due to such a difference, for example, 80
Even if a frequency converter that simply performs frequency conversion is used with a 0 MHz band digital cellular terminal, 1.5 GHz
It cannot be used as a terminal for obi digital cellular. Similarly, PCN terminals cannot be used as GSM terminals.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is a communication system in which transmission and reception are performed in a time division manner, and a first communication having different allocated frequency bandwidths. When the communication method and the second communication method exist, the second transmission / reception device corresponding to the first communication method
The present invention provides a frequency conversion device for transmitting and receiving communication signals according to the communication method of (1) and a transmission / reception device including such a frequency conversion device.

The frequency conversion device selects a reception mixed frequency for a predetermined frequency of the received signal in the used frequency band of the second communication system to select the received signal in the used frequency band of the first communication system. The frequency of the second communication method is converted into a predetermined frequency, and a mixed frequency at the time of transmission that is different from the mixed frequency at the time of reception is selected for the predetermined frequency of the transmission signal in the frequency band used in the first communication method. It is configured so that it can be converted into a predetermined frequency of the transmission signal in the used frequency band.

Further, in the first and second communication systems,
In particular, the frequency bandwidth used in the second communication method is the first
As a frequency conversion device when the frequency bandwidth is wider than the frequency band used in the second communication system, each band in the frequency band used in the second communication system, which is divided into a plurality of frequency bands or divided into a plurality of frequency bands. With respect to the predetermined frequency of the received signal, one of a plurality of reception mixed frequencies is selected and converted into a predetermined frequency of the received signal in the use frequency band of the first communication method. Use frequency band of the second communication method by selecting one of a plurality of transmission-time mixed frequencies different from the reception-time mixed frequency for the predetermined frequency of the transmission signal in the use frequency band of the first communication method It is configured so that it can be converted into a predetermined frequency of the transmission signal in.

[0013]

In the communication system employing the time division multiplex system in which transmission and reception are performed in time division, different frequencies can be mixed in the transmission signal at the time of transmission and the reception signal at the time of reception. It is possible to perform frequency conversion according to the used frequency bandwidth or the frequency difference between the upper and lower lines.

[0014]

FIG. 1 is a block diagram showing a first embodiment of a frequency conversion device of the present invention.
By attaching to a 0MHz band digital cellular telephone, the telephone can be used as a 1.5GHz band digital cellular telephone. Thirty
Indicates an 800MHz band digital cellular telephone (hereinafter referred to as an 800MHz telephone).

Reference numeral 1 surrounded by a one-dot chain line indicates a frequency conversion device, which is provided with an antenna terminal portion 2 connected to a transmission / reception antenna AN and is connected to an antenna terminal portion 31 of an 800 MHz telephone 30. A terminal portion 3 is provided.

Further, a T / R signal terminal portion 4 is provided so that a T / R signal, which will be described later, is supplied from the 800 MHz telephone 30 so as to be connected to the T / R signal terminal portion 32 of the 800 MHz telephone 30. The control information terminal unit 5 is provided to exchange information signals between the CPU 34 which is the system control means of the 800 MHz telephone 30 and the CPU 6 which is the system control means of the frequency conversion device 1. It is made to be connected with 33.

The 800 MHz telephone 30 is provided with a NAM (Number Asin Memory) 35 that stores information necessary for the 800 MHz telephone, such as a telephone number and a serial number, so that the CPU 34 can use the information in the NAM 35. However, even in the frequency conversion device 1, the NA
M7 is provided, and CPU 6 reads / writes information. The NAM 7 stores information such as a telephone number and a serial number as a 1.5 GHz band digital cellular telephone (hereinafter referred to as 1.5 GHz telephone).

The 1.5 GHz band received signal received by the antenna AN and guided to the antenna terminal section 2 is supplied to the T / R switch 9 via the low-pass filter 8 (for transmission), and the R signal of the T / R switch 9 is supplied. It is supplied to the bandpass filter 10 having a center frequency of 1.5 GHz in the pass band through the contact point and only the received signal is extracted.

Further, the received signal is a low noise amplifier 11
In the mixer circuit 1
As will be described later in 2, the signals of a predetermined frequency are mixed and converted into a predetermined frequency of 800 MHz band, and then passed through a band pass filter 13 having a center frequency of 800 MHz in a pass band, and a T / R switch 14 To the R terminal. Then, it is guided from the T / R switch 14 to the terminal portion 3, outputted from the frequency conversion device 1, and supplied to the antenna terminal portion 31 of the 800 MHz telephone 30.

The 800 MHz band transmission signal output from the antenna terminal section 31 of the 800 MHz telephone 30 is guided from the terminal section 3 to the T / R switch 14, passes through the T contact of the T / R switch 14, and is attenuator. 15 dB, for example 20 dB
It is attenuated to some extent. Then, in the mixer circuit 16, as will be described later, signals of a predetermined frequency are mixed and converted to a frequency of 1.5 GHz band (1.44 GHz), and then passed through a band pass filter 17 having 1.44 GHz as the center frequency of the pass band. Then, it is further amplified by the power amplifiers 18 and 19 to a required power, for example 2.0 W, and supplied to the low pass filter 8 from the T contact of the T / R switch 9. This low pass filter 8
After the harmonic signal component of the transmission signal is cut by, the signal is guided from the antenna terminal portion 2 to the antenna AN and radiated.

An antenna duplexer (dielectric duplexer) may be used in place of the T / R switch 7 and the bandpass filter 10. The same applies to the T / R switch 14 and the bandpass filter 13.

Reference numerals 20 and 21 denote local oscillators. A signal of 667 MHz or 691 MHz is output from the local oscillator 20 and supplied to the mixer circuit 12 via the switch circuit 22. A signal of 489 MHz or 513 MHz is output from the local oscillator 21 and supplied to the mixer circuit 16 via the switch circuit 23. Reference numeral 24 denotes a power supply circuit unit that supplies power to each unit.

As described above, the transmission / reception operation of the 800 MHz telephone 30 is performed by the time division multiplexing method, and the frequency conversion device 1 is processed according to the communication protocol of the 800 MHz telephone 30. Therefore, the reception / transmission switching timing control in the frequency converter 1 is 800M.
Hz T / R supplied from the T / R signal terminal section 4 of the telephone 30
This is done by the R signal. That is, the T / R switch 9,
14 T contact and R contact switching, and switch circuit 22,
The opening / closing of 23 is executed based on the T / R signal, and at the time of reception, the R contacts of the T / R switches 9 and 14 are connected and the switch circuit 22 is turned on. Further, at the time of transmission, the T contacts of the T / R switches 9 and 14 are connected, and the switch circuit 23
Is turned on.

With the frequency converter 1 of the present embodiment having the above-described configuration, the 800 MHz telephone 30 functions as a 1.5 GHz band transmission / reception terminal. That is, when a signal in the 1.5 GHz band is received by the antenna AN and input (because the information stored in the NAM 7, such as the telephone number and serial number of the 1.5 GHz terminal, is sent to the CPU 34). , 1.
The 800 MHz telephone 30 performs a predetermined incoming operation on the call signal of 5 GHz), and the received signal is supplied to the 800 MHz telephone 30 via the frequency conversion device 1 as described above. From 667MHz or 69
A 1 MHz signal is output and supplied to the mixer circuit 12. Therefore, the received signal is frequency-converted to 810 to 826 MHz. Therefore, a received signal in the 800 MHz band is input to the 800 MHz telephone 30 and operates in the same manner as in the case of communication in the 800 MHz band digital cellular system.

The output of the local oscillator 20 is 667 MHz or
As shown in Fig. 5, 691MHz is assigned because two bands, 1477 to 1489MHz and 1501 to 1513MHz, are allocated as downlinks from the base station to the mobile in the 1.5GHz digital cellular system. For example, if the received signal is 1477 to 1489MHz, 667MHz, the received signal is 1501 to
In the case of 1513MHz, it is controlled to generate 691MHz.

Also, the 80 output from the 800 MHz telephone 30
As described above, the 0 MHz band transmission signal is also supplied to the antenna AN via the frequency conversion device 1 and radiated. At this time, the local oscillator 21 outputs a 489 MHz or 513 MHz signal, and the mixer circuit 16 receives the signal. Is being supplied. Therefore, the transmission signal of 810-826MHz is 1429-1441MHz or 1429MHz
The frequency is converted to 53 to 1465MHz. Therefore, it is radiated to the base station as a 1.5 GHz digital cellular communication radio wave.

The output of the local oscillator 21 is 489 MHz or
As shown in FIG. 5, the frequency of 513 MHz is 1429 to 1441 MHz and 1453 to 1465 MHz for the uplink from the mobile unit to the base station in the 1.5 GHz digital cellular system.
This is because one band is allocated, 940-956M
The output of the local oscillator 21 is 489MHz for the transmission signal of Hz.
When it is, it is converted to 1429 to 1441 MHz, and when the output of the local oscillator 21 is 513 MHz, it is converted to 1453 to 1465 MHz.

Selection of mixed frequency for received signal (667M
(Hz or 691MHz) and the selection of the mixed frequency for the transmission signal (489MHz or 513MHz), CPU34 (800MHz telephone 3
0 communication protocol) is performed via the CPU 6.

By connecting the frequency conversion device 1 of this embodiment in this way, the 800 MHz telephone 30 can be used as a 1.5 GHz transmission / reception terminal, and the convenience is significantly improved. Further, the frequency conversion device 1 need only have information such as a telephone number in addition to at least the frequency conversion unit, and does not need to be equipped with a communication protocol or the like, and therefore can be realized easily and at low cost.

By the way, in this embodiment, the frequency converter 1 is used.
The 800 MHz telephone 30 and the frequency conversion device 1 are described as additional devices to the 800 MHz telephone 30, but the same components as the frequency conversion device 1 may of course be incorporated in the 800 MHz telephone.

Next, a frequency converter 40 as a second embodiment of the present invention will be described with reference to FIG. This frequency converter 40
Attaches the PCN terminal to the PCN terminal,
It is intended to be used as an SM terminal. 50 indicates a PCN terminal. In the figure, the parts corresponding to those of the embodiment of FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

However, the center frequency of the pass band of the band pass filter 10 is 1823 MHz, the band pass filter 13 is 945 MHz, and the band pass filter 17 is 900 MHz.
Is. Further, the NAM 7 stores a telephone number and a serial number as a GSM terminal. PC of course
A telephone number and a serial number as a PCN terminal are stored in the NAM 35 of the N terminal 50, and the CPU 34 is the PCN.
Operates according to the communication protocol. The operation of the CPU 6 also operates according to the PCN communication protocol of the CPU 34.

In this embodiment, the high speed synthesizer 42 is used.
A frequency offset unit 41 including a bandpass filter 43 and a high-speed synthesizer 42 is provided.
The T / R signal supplied from the PCN terminal 50 (or the T / R signal) causes the 870 MHz oscillation output when receiving the GSM signal and the 820 MHz oscillation output when transmitting the GSM signal.
It is controlled by the CPU 6 based on the signal).

That is, the antenna A transmitted from the base station
GSM signal received by N (935-960 MHz: FIG. 6)
(Reference) is mixed with a 870 MHz signal in the mixer circuit 12 and converted into a signal of 1805 to 1830 MHz. And P
The data is input to the CN terminal 50 and subjected to reception processing. In addition, PC
The N downlink bandwidth is 75MHz, which is wider than GSM 25MHz, so 1831 to 1880MH of the PCN downlink bandwidth.
z is not used in particular.

On the other hand, at the time of transmission, a signal in the PCN band is input to the frequency conversion device 40, but the high speed synthesizer 4
An oscillation output of 820 MHz, which is shifted by 50 MHz from the time of reception, is made from 2 and supplied to the mixer circuit 16.

Here, the bandwidth of the uplink of the PCN is 1710-
Although it is 1785MHz, when transmitting / receiving GSM, the PCN terminal 5
The transmission output from 0 uses 1710 to 1735 MHz of this, and therefore the output of the mixer circuit 16 is 890 to 91.
It will be converted to a frequency of 5MHz. That is, GSM
Corresponding to the frequency band of the uplink. The transmission output from the PCN terminal 50 may be 1735 to 1785 MHz, but in that case, the mixing frequency supplied to the mixer circuit 16 must be changed. For example,
When it is 1735 to 1760MHz, it is 845MHz, and when it is 1760 to 1785MHz, it is 870MHz. The frequency-converted signal is amplified and then radiated from the antenna AN toward the base station.

Thus, the frequency conversion device 40 of this embodiment
By connecting the PCN terminal 50 to the PCN terminal 50, the PCN terminal 50 can be used also as a GSM terminal, and the convenience is significantly improved. Also in this case, the frequency conversion device 40 need only have information such as a telephone number in addition to at least the frequency conversion unit, and does not require a communication protocol or the like, so that it can be realized easily and at low cost. Particularly, in the case of GSM and PCN, since the frequency of the upper and lower lines is not the opposite of that of the frequency, the means for generating the mixed frequency (frequency offset unit 41) can be realized more easily than in the first embodiment.

3 and 4 show another example of the configuration of the frequency offset section 41. In FIG. 3, a local oscillator 44T of 820 MHz and a local oscillator 44R of 870 MHz are provided, and switches 45T and 45R are T / R. The band-pass filter 43 is received at the time of reception by alternately controlling the opening and closing of the signal.
870M of local oscillator 44R to mixer circuit 12 via R
The output of Hz is supplied, and the band pass filter 4 at the time of transmission.
Of the local oscillator 44T to the mixer circuit 16 via the 3T.
The output of 820MHz is supplied.

Further, in the case of FIG. 4, a local oscillator 46 of 820 MHz, a local oscillator 46 _{OF of} 50 MHz, and a mixer circuit 47 are provided, and switch circuits 48 and 49 which are controlled to open / close by a T / R signal are provided. Be done. T when receiving
The switch circuit 49 is turned on and the switch circuit 48 is turned off by the / R signal, so that the 820 MHz output of the local oscillator 46 and the 50 MHz output of the local oscillator 46 _OF are mixed by the mixer circuit 47.
Mixed to produce an 870MHz output. And
The 870 MHz output is supplied to the mixer circuit 12 via the bandpass filter 43.

At the time of transmission, the switch circuit 49 is turned off and the switch circuit 48 is turned on by the T / R signal, so that the 820 MHz output of the local oscillator 46 is directly supplied to the mixer circuit 16 via the bandpass filter 43. For example, in addition to FIGS. 3 and 4, various configurations of the frequency offset unit 41 can be considered.

In the second embodiment as well, the frequency converter 40 and the PCN terminal 50 are constructed separately, but the same components as the frequency converter 40 are provided in the PCN terminal 50.
May be built into.

On the contrary to the case of the second embodiment, when a GSM terminal can be shared as a PCN type terminal having a wider bandwidth, for example, the mixed frequency is simply offset between transmission and reception. It cannot be realized only by giving and changing. Therefore, a plurality of frequency bands of received signals (for example, 1805 to 1880 MHz of PCN) are provided (for example, 1805 to 1805).
1830MHz, 1831 ~ 1855MHz, 1856 ~ 1880MHz), and different mixed frequencies are selected depending on which band contains the received signal and which band is designated as the transmitted signal. You should do so. This process may be considered in the same manner as in the first embodiment (that is, in the first embodiment, since the line frequency of the digital cellular of 1.5 GHz is divided in advance, there are two types of transmission / reception. Mixed frequencies are available).

Although various embodiments have been described above, the present invention is not limited to the frequency conversion device or the transmission / reception terminal incorporating the frequency conversion device, and can be applied as a terminal sharing means between various communication systems. ..

[0044]

As described above, the frequency converter of the present invention, or the transmitter / receiver incorporating the frequency converter, selects and mixes different frequencies for the transmission signal at the time of transmission and the reception signal at the time of reception. However, by performing frequency conversion, it becomes possible to share the terminal between different communication methods such as the used frequency bandwidth and the frequency difference between the upper and lower lines, which has the effect of significantly improving convenience. ..

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of a second embodiment of the present invention.

FIG. 3 is a block diagram of a modification of the frequency offset unit of the second embodiment.

FIG. 4 is a block diagram of a modification of the frequency offset unit of the second embodiment.

FIG. 5 is an explanatory diagram of frequency bands used in the digital cellular communication system of 800 MHz band and 1.5 GHz band.

FIG. 6 is an explanatory diagram of frequency bands used in the GSM system and the PCN system.

[Explanation of symbols]

 1,40 Frequency converter 6,34 CPU 7,35 NAM 12,16 Mixer circuit 20,21 Local oscillator 30 800MHz telephone 41 Frequency offset unit 50 PCN terminal

Claims (3)

[Claims] 1. A communication system in which transmission and reception are performed in a time division manner, and when there is a first communication system and a second communication system having different allocated frequency bandwidths, the first communication system. As a frequency conversion device for transmitting / receiving a communication signal according to the second communication method in a transmitting / receiving device corresponding to, a reception-time mixing for a predetermined frequency of a reception signal in a use frequency band of the second communication method. A frequency is selected and converted to a predetermined frequency of a reception signal in the use frequency band of the first communication method, and the frequency is converted to a predetermined frequency of the transmission signal in the use frequency band of the first communication method. It is possible to select a mixed frequency for transmission different from a mixed frequency for reception and convert it to a predetermined frequency of a transmission signal in the frequency band used by the second communication method. A frequency conversion device characterized by being configured. 2. A communication method in which transmission and reception are performed in a time division manner, and there are a first communication method and a second communication method having different allocated frequency bandwidths, and the second communication method is used. When the frequency bandwidth used is wider than the frequency bandwidth used in the first communication method, the transmission / reception device corresponding to the first communication method transmits and receives the communication signal according to the second communication method. As a frequency conversion device for, for each band in the use frequency band of the second communication method, which is divided into a plurality of frequency bands or divided into a plurality of frequency bands, with respect to a predetermined frequency of the received signal , Selecting one of a plurality of reception mixed frequencies and converting it to a predetermined frequency of a received signal in a frequency band used by the first communication method, and a frequency used by the first communication method. For a predetermined frequency of a transmission signal in several bands, one of a plurality of transmission-time mixed frequencies different from the reception-time mixed frequency is selected to select a transmission signal in a use frequency band of the second communication method. A frequency conversion device, which is configured to be capable of converting to a predetermined frequency. 3. A communication method in which transmission and reception are performed in a time division manner, and when there are a first communication method and a second communication method having different allocated frequency bandwidths, the first communication method. A transmitting / receiving device having a function corresponding to, wherein a reception mixed frequency is selected for a predetermined frequency of a received signal in a frequency band used by the second communication method, and a frequency used by the first communication method is selected. The received signal in the band is converted to a predetermined frequency, and a transmission mixed frequency different from the reception mixed frequency is selected for the predetermined frequency of the transmission signal in the use frequency band of the first communication method. And a frequency conversion unit configured to convert the transmission signal into a predetermined frequency in the frequency band used in the second communication method.