JP3100029B2 - Wireless signal transmission method, wireless signal transmission system, and base station - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an economical radio signal transmission method and system of a digital mobile communication system.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional digital mobile communication system base station. In this base station, the base station transceiver 2
A coaxial cable or an optical fiber is used as the wireless signal transmission path 4 from the antenna 3 to the external antenna 3. In the mobile communication system, when one base station is composed of three sectors, one base station is used for one line in the downlink which is a transmission system, and one sector is used in the uplink when diversity reception is used as a radio signal reception system. Requires two lines, for a total of three lines. That is, at present, a base station mainly composed of three sectors requires a total of nine lines. Currently, one line is assigned to each transmission line for transmission lines such as coaxial cable and optical fiber.
The main base station requires nine transmission paths.

The optical fiber transmission line has a feature that the cable diameter is smaller than that of a coaxial cable, the weight is light, and the laying order can be simplified. On the other hand, the transmission of an electric signal such as a radio signal through an optical fiber requires transmission. The optical signal must be converted once into an optical signal on the transmitting side and transmitted to the optical fiber, and the optical signal must be converted into an electric signal on the receiving side. Conventionally, expensive laser diodes have been used to perform this conversion.

[0004]

As a method of reducing the cost of the entire transmission line including the transmission device in the base station, a plurality of radio signals are combined by a frequency multiplexing method to reduce the number of transmission lines and the number of laser diodes. Can be achieved by reducing

However, with such a configuration, it is necessary to frequency-convert the radio signal to be transmitted twice at both ends of the transmission path. For this reason, the frequency accuracy of the wireless signal in the frequency conversion becomes a problem. The frequency accuracy of the base station transceiver in the digital mobile communication standard is 0.05 × 1
Defines at 0 ^-6 (digital mobile telephone system / RCR STD-27D: see). For this reason, it has been necessary to perform frequency conversion of a radio signal based on the output of a highly accurate and expensive standard signal generator such as a rubidium standard signal generator.

According to the present invention, when synthesizing a plurality of radio signals by a frequency multiplexing method, a standard signal (reference signal) is formed using an inexpensive standard signal generator without using a high-precision standard signal generator. By generating, frequency conversion of frequency multiplexing is performed with the same accuracy as that of an expensive standard signal generator.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive and high-precision standard signal for transmitting a radio signal by frequency multiplexing in digital mobile communication.

According to a first aspect of the present invention, there is provided a method for transmitting a plurality of radio signals, wherein the first radio control signal which is a radio control signal of any of the plurality of radio signals is automatically detected, and Generating a first reference signal having the same frequency accuracy as the first wireless control signal based on the one wireless control signal;
The plurality of wireless signals are frequency-converted based on the first reference signal, the plurality of frequency-converted wireless signals are combined to generate a combined signal, the combined signal is transmitted, and the transmitted combined signal is transmitted. To generate a plurality of frequency-converted wireless signals, automatically detect a second wireless control signal that is a wireless control signal of any of the plurality of frequency-converted wireless signals, A second reference signal having the same frequency accuracy as the second wireless control signal is generated based on the control signal, and the plurality of wireless signals frequency-converted based on the second reference signal are frequency-converted. A plurality of wireless signals are restored, and a phase locked loop circuit is used for generating the first reference signal and / or generating the second reference signal.

According to a second aspect of the present invention, there is provided a method for transmitting a plurality of radio signals, wherein the radio control signal which is a radio control signal of any one of the plurality of radio signals is automatically detected and the radio control signal is transmitted. Generating a first reference signal having the same frequency accuracy as the wireless control signal based on the reference signal, frequency-converting the plurality of wireless signals based on the reference signal, and combining the plurality of frequency-converted wireless signals To generate a composite signal,
Transmitting the composite signal and the reference signal, generating the plurality of frequency-converted wireless signals by demultiplexing the transmitted composite signal, and performing the frequency conversion on the basis of the transmitted reference signal. The frequency of the wireless signal is converted to restore the plurality of wireless signals.

According to a third aspect of the present invention, there is provided a method of transmitting a plurality of radio signals from a base station transmitting / receiving apparatus in a base station, wherein the first radio signal is a radio control signal of one of the plurality of radio signals. A control signal is automatically detected, a first reference signal having the same frequency accuracy as the first wireless control signal is generated based on the first wireless control signal, and the plurality of wireless signals are generated based on the first reference signal. The signal is frequency-converted, the plurality of frequency-converted wireless signals are combined to generate a combined signal, the combined signal is transmitted, and the transmitted combined signal is demultiplexed and frequency-converted. Generating a wireless signal, automatically detecting a second wireless control signal that is a wireless control signal of any of the plurality of frequency-converted wireless signals, and determining the second wireless control signal based on the second wireless control signal; Same frequency accuracy That generates a second reference signal, wherein the second reference signal by frequency converting the plurality of radio signal frequency-converted based on restoring said plurality of wireless signals.

According to a fourth aspect of the present invention, there is provided a system for transmitting a plurality of radio signals, wherein a means for automatically detecting a first radio control signal, which is a radio control signal of any of the plurality of radio signals, Means for generating a first reference signal having the same frequency accuracy as the first wireless control signal based on the first wireless control signal, and frequency-converting the plurality of wireless signals based on the first reference signal Means, means for synthesizing the plurality of frequency-converted radio signals to generate a synthesized signal, a transmission path for transmitting the synthesized signal, and frequency-converted by separating the transmitted synthesized signal. Means for generating a plurality of wireless signals, means for automatically detecting a second wireless control signal that is a wireless control signal of any of the plurality of wireless signals subjected to frequency conversion, and the second wireless control signal based on the second wireless control signal Second wireless control signal Second with the same degree of frequency accuracy
Means for generating a reference signal, and means for frequency-converting the plurality of wireless signals frequency-converted based on the second reference signal to restore the plurality of wireless signals, and generating the first reference signal; And / or using a phase locked loop circuit to generate the second reference signal.

According to a fifth aspect of the present invention, there is provided a system for transmitting a plurality of wireless signals, wherein the means for automatically detecting a wireless control signal which is a wireless control signal of any one of the plurality of wireless signals; Means for generating a first reference signal having the same frequency accuracy as the radio control signal based on the control signal; means for frequency-converting the plurality of radio signals based on the reference signal; Means for combining a plurality of wireless signals to generate a combined signal; a transmission path for transmitting the combined signal and the reference signal; and a plurality of wireless signals that are frequency-converted by separating the transmitted combined signal. And a means for restoring the plurality of wireless signals by frequency-converting the plurality of wireless signals frequency-converted based on the transmitted reference signal.

According to a sixth aspect of the present invention, in the wireless signal transmission system according to the fifth aspect, a phase locked loop circuit is used for generating the reference signal.

According to a seventh aspect of the present invention, there is provided a base station, comprising: a base station transmitting / receiving apparatus; and a first radio control signal, which is one of a plurality of radio signals from the base station transmitting / receiving apparatus. Means for automatically detecting, means for generating a first reference signal having the same frequency accuracy as the first wireless control signal based on the first wireless control signal, and means for generating the plurality of signals based on the first reference signal Means for frequency-converting the radio signal;
Means for synthesizing the plurality of frequency-converted radio signals to generate a synthesized signal, a transmission path for transmitting the synthesized signal, and the plurality of radio waves frequency-converted by demultiplexing the transmitted synthesized signal. Means for generating a signal, means for automatically detecting a second wireless control signal, which is a wireless control signal of any of the plurality of frequency-converted wireless signals, and means for detecting the second wireless signal based on the second wireless control signal Means for generating a second reference signal having substantially the same frequency accuracy as the control signal, and means for frequency-converting the plurality of wireless signals frequency-converted based on the second reference signal to restore the plurality of wireless signals And characterized in that:

[0015]

[0016]

The conventional technology is greatly different from the conventional technology in that a high-precision standard signal required for frequency conversion of a radio signal is generated without using an expensive standard signal generator.

[0018]

FIG. 1 is a block diagram showing an example of a signal generator for producing a high-precision standard signal according to the present invention.

In FIG. 1, the bandpass filter 6 operates so as to extract a band to which a radio control signal is assigned from a radio signal transmitted from the base station transmitting / receiving device 5. The receiving unit 7 operates to automatically detect a radio control signal having a different frequency assigned by each base station and report the frequency to the control unit 8. The control unit 8 includes a variable frequency divider 10 for dividing the frequency of the wireless control signal amplified by the preamplifier 9 based on the frequency reported by the receiving unit 7, and an inexpensive VCO (voltage controlled oscillator) such as a quartz oscillator. A variable frequency divider 12 that divides the signal from the frequency divider 11 receives a frequency division ratio M
And the frequency division ratio N. The phase comparator 13 operates so that the phase of the radio control signal divided by the variable frequency divider 10 and the variable frequency divider 12 is compared with the signal of the VCO, and the output signal is input to the VCO 11 by the loop configuration of this circuit. doing. The buffer 14 includes the VCO 11
And operates to buffer and amplify the signal from These constitute a PPL (Phase Locked Loop). As a result, since the signal generator 15 having the above configuration uses a high-precision wireless control signal as a reference, it is possible to generate a standard signal fs having almost the same accuracy as the wireless control signal.

In this case, the frequency f _{r of} the received radio control signal and the frequency f s of the standard signal are

[0021]

[Number 1] a relationship of _{f r / M = f s /} N.

(Embodiment 1) FIG. 2 shows a first embodiment of the present invention. This shows a configuration for frequency-multiplexing the signal of the base station transmitting / receiving device 5 using the signal generating device 15 shown in FIG. 1 and transmitting / receiving the signal to / from the antenna.

[0023] In FIG 2, the transmission-side signal generator 15 ₁ to input wireless control signal from the base station transceiver produces a reference signal fs from the N divider 16, a synthesizer 17 _{1,2, ... , N} are distributed standard signals. And
In the synthesizers 17 _{1,2, ..., N 1,2, ..., N} , the frequencies (f ' ₁ -f ₁ ), (f) for converting one or more radio signals from the standard signal f _s ' ₂ -f ₂ ), ...,
(F ′ _N −f _N ).

The frequency generated above (f ' ₁ -f
₁ ), (f ′ ₂ −f ₂ ),..., (F ′ _N −f _N ) are mixers on the transmitting side for frequency-converting each radio signal group of the frequency groups f _1,2 ,. 18 Input to _{1,2, ..., N.} Frequency f
The radio signal group of each channel of _{1, 2} ,.
_{, N} are frequency-converted into radio signal groups of frequency groups f ′ _1,2,. The converted wireless signal groups are combined and transmitted on one transmission path. This is, for example, a transmission path to the antenna. The transmitted synthesized radio signal is subjected to frequency group f ′ by bandpass filters 19 _1,2 ,.
_The signals are demultiplexed into _{1, 2, ..., N} radio signal groups. On the other hand, the receiving-side signal generator ₁ having the same configuration as the transmitting-side signal generator 151
5 ₂ are prepared in the transmission path receiver. Also in this receiving side device, a standard signal fs is created from any of the radio control signals in each radio signal group of frequencies _{f'1,2, ..., N.}
Standard signal fs distributes at N divider 16 _2. And
In the synthesizers 20 _{1,2,..., N} , each transmitted radio signal group of the transmitted frequency group f ′ _1,2 ,.
Frequency (f ₁₎ for converting into a group of _{1,2, ..., N} radio signals
−f ′ ₁ ), (f ₂ −f ′ ₂ ),..., (F _N −f ′ _N )
Produces a signal. The frequency (f ₁ −
_{f '1), (f 2} -f' 2), ..., (f N -f ' signal _N) and frequency f' _{1,2, ...,} of each radio signal group _N respectively mixers 21 _{1 , 2, ...,} by inputting the _N, frequency groups f _{1, 2} of the original _{signal, ...,} frequency groups f _{"1, 2} at _N and same _{accuracy, ...,} a _N can produce a radio signal. frequency group original signal f _{1, 2, ...,} after the transmission and _N reconverted to produce the frequency group f _{"1,2, ...,} the accuracy of the _N signal Generator 1
5 _1, 15 depends on the standard signal fs of precision produced from _2. In this case, with the circuit configuration of FIG. 1, the VCO 11, which is an inexpensive transmission source, uses a radio signal from a base station transmitting / receiving device having high frequency accuracy as a reference, so that oscillation with approximately the same accuracy can be obtained. By using the standard signal fs of the signal generating device 15 which is a configuration example of the present invention, a plurality of radio signals can be transmitted with a small number of transmission paths by using a high-precision frequency.

The above description is based on the assumption that the equipment inside the base station
The down direction, which is the direction of the device, is described. How to climb
Similarly, the down direction signal generator 15₁ ,
Fifteen _Two Based on the reference signal fs generated by the₁ ,
16_Two , Synthesizer 17_{1,2, ..., N} , 20
_{1,2, ..., N} , Mixer 18_{1,2, ..., N} , 21_{1,2, ..., N} ,
The bandpass filter 19 is configured as shown in the lower part of FIG.
And allows multiple wireless signals to be more accurate and less
Can be transmitted over a large number of transmission paths.

[0026] (Embodiment 2) FIG. 3 is a second embodiment of the present invention, even if the standard signal of the receiving standard signal fs that created by the transmission-side signal generating unit 15 ₁ described in Embodiment 1 Use.

[0027] Similar to the transmission side configuration shown in FIG. 2, the standard signal f _s generated by a signal generator 15 _1, a frequency group f
_{, N obtained} by converting _{1, 2,..., N} are synthesized, and frequency multiplexing is performed.

Further, the combined standard signal fs from the signal generator 15 ₁ to the frequency-multiplexed signal is transmitted to a transmission line.

On the receiving side, only the standard signal fs is extracted by the bandpass filter 22. By using this standard signal fs, the receiving side can retrieve the standard signal fs without preparing a reception-side signal generator 15 ₂ described in embodiment 1. Standard signal fs transmitted produced by the transmission-side signal generator 15 ₁ is distributed by the distributor 16 _2, each synthesizer 20 _{1,2, ...,} the transmitted frequency group f by _{N '1,2,. .., N} is converted to the original frequency group f
Frequency (f ₁₎ for converting into a group of _{1,2, ..., N} radio signals
−f ′ ₁ ), (f ₂ −f ′ ₂ ),..., (F _N −f ′ _N )
Produce a wireless signal. The frequency for conversion (f
₁₋ f ′ ₁ ), (f ₂ −f ′ ₂ ),..., (F _N −f ′)
Wireless signal _N) and frequency groups f _{'1, ...,} each of the mixers 21 _{1 and 2} each radio signal group _{N, ...,} by inputting the _N, frequency groups of the original signal f, _{2, ..., N} and a small frequency group f ″ _{1,2, ..., N} creates a radio signal group. Since the standard signal fs has high frequency accuracy, , Frequency group f ″ created by re-conversion after transmission
_{The difference between 1,2, ..., N} and the original frequency group f _{1,2, ..., N} is small.

A signal generator 15 ₁ which is a configuration example of the present invention.
Can transmit a plurality of wireless signals with a high-precision frequency and with a small number of transmission paths.

Although the present embodiment has described the downlink direction, which is the direction from the device inside the base station to the device outside the base station, a plurality of radios are also converted in the uplink by using the standard signal fs transmitted in the downlink. A signal group can be transmitted with higher accuracy and a smaller number of transmission paths.

[0032]

As described above, according to the present invention, a circuit for producing a high-precision standard signal is provided at low cost, and a plurality of radio signal groups are transmitted through a smaller number of transmission paths by using the standard signal. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an operation example of the present invention.

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

FIG. 3 is a block diagram showing one embodiment of the present invention.

FIG. 4 is a diagram illustrating an example of a conventional base station.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Digital mobile communication system base station 2 Digital mobile communication system base station transmitter / receiver 3 Digital mobile communication system base station outdoor apparatus 4 Transmission line 5 Base station transmitter / receiver 6 Band filter 7 Receiver 8 Controller 9 Preamplifier 10 Variable frequency divider 11 VCO (Voltage Controlled Oscillator) 12 Variable frequency divider 13 Phase comparator 14 Buffer 15 ₁ , 15 ₂ Signal generator 16 ₁ , 16 ₂ N distributor 17 ₁ , 17 ₂ , 17 _N , 20 ₁ , 20 ₂ , 20 _N synthesizer 18 transmitter mixer 19 ₁ , 19 ₂ , 19 _N band filter 20 synthesizer 21 ₁ , 21 ₂ , 21 _N receiver mixer 22 band filter

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-252559 (JP, A) JP-A-4-7923 (JP, A) JP-A-3-214890 (JP, A) International Publication 96/1545 (WO, A1) (58) Fields surveyed (Int. Cl. ⁷ , DB name) H04B ^7/ 24-7/26 H04Q ⁷ /04-7/38 H04J 1/04

Claims (7)

(57) [Claims] 1. A method for transmitting a plurality of wireless signals, comprising: automatically detecting a first wireless control signal, which is a wireless control signal of any of the plurality of wireless signals, based on the first wireless control signal Generating a first reference signal having substantially the same frequency accuracy as the first wireless control signal; performing frequency conversion on the plurality of wireless signals based on the first reference signal; converting the plurality of frequency-converted wireless signals; Combining to generate a synthesized signal; transmitting the synthesized signal; demultiplexing the transmitted synthesized signal to generate a plurality of frequency-converted wireless signals; and generating a plurality of frequency-converted wireless signals. Automatically detecting a second wireless control signal that is any one of the wireless control signals, generating a second reference signal having a frequency accuracy equivalent to that of the second wireless control signal based on the second wireless control signal, Frequency change based on the second reference signal Frequency converting the converted plurality of radio signals to restore the plurality of radio signals, and using a phase locked loop circuit for generating the first reference signal and / or generating the second reference signal. Wireless signal transmission method. 2. A method for transmitting a plurality of wireless signals, the method comprising: automatically detecting a wireless control signal that is a wireless control signal of any of the plurality of wireless signals; and controlling the wireless control signal based on the wireless control signal. Generating a first reference signal having the same frequency accuracy as the first reference signal, frequency-converting the plurality of wireless signals based on the reference signal, and combining the plurality of frequency-converted wireless signals to generate a combined signal Transmitting the synthesized signal and the reference signal, generating the plurality of frequency-converted wireless signals by demultiplexing the transmitted synthesized signal, and performing frequency conversion based on the transmitted reference signal. A wireless signal transmission method, comprising: converting a plurality of wireless signals to restore the plurality of wireless signals. 3. A method for transmitting a plurality of wireless signals from a base station transmitting / receiving apparatus in a base station, the method comprising: automatically detecting a first wireless control signal that is a wireless control signal of any of the plurality of wireless signals; Generating a first reference signal having substantially the same frequency accuracy as the first wireless control signal based on the first wireless control signal; performing frequency conversion on the plurality of wireless signals based on the first reference signal; Combining the plurality of converted wireless signals to generate a combined signal; transmitting the combined signal; demultiplexing the transmitted combined signal to generate the plurality of frequency-converted wireless signals; A second wireless control signal, which is one of the converted plurality of wireless signals, is automatically detected, and has the same frequency accuracy as the second wireless control signal based on the second wireless control signal. The second reference signal Forms, radio signal transmission method characterized by restoring the plurality of radio signals to the plurality of radio signal frequency-converted based on the second reference signal by frequency conversion. 4. A system for transmitting a plurality of wireless signals, comprising: means for automatically detecting a first wireless control signal that is a wireless control signal of any of the plurality of wireless signals; Means for generating a first reference signal having the same frequency accuracy as the first wireless control signal based on the first wireless control signal; means for frequency-converting the plurality of wireless signals based on the first reference signal; Means for combining the plurality of wireless signals to generate a combined signal; a transmission path for transmitting the combined signal; and generating a plurality of frequency-converted wireless signals by separating the transmitted combined signal. Means for automatically detecting a second wireless control signal, which is a wireless control signal of any of the plurality of wireless signals subjected to frequency conversion, and the same as the second wireless control signal based on the second wireless control signal. Frequency accuracy Means for generating a second reference signal having: and means for restoring the plurality of wireless signals by frequency-converting the plurality of wireless signals frequency-converted based on the second reference signal; A wireless signal transmission system using a phase locked loop circuit for generating a signal and / or generating the second reference signal. 5. A system for transmitting a plurality of wireless signals, comprising: means for automatically detecting a wireless control signal that is a wireless control signal of any of the plurality of wireless signals; and Means for generating a first reference signal having the same frequency accuracy as the control signal; means for frequency-converting the plurality of wireless signals based on the reference signal; and combining the plurality of frequency-converted wireless signals. Means for transmitting the combined signal and the reference signal; means for splitting the transmitted combined signal to generate the plurality of frequency-converted wireless signals; Means for frequency-converting the plurality of wireless signals frequency-converted based on the reference signal thus obtained to restore the plurality of wireless signals. 6. The wireless signal transmission system according to claim 5, wherein a phase locked loop circuit is used for generating the reference signal. 7. A base station, comprising: a base station transmitting / receiving apparatus; a means for automatically detecting a first wireless control signal that is a wireless control signal of any of a plurality of wireless signals from the base station transmitting / receiving apparatus; Means for generating a first reference signal having substantially the same frequency accuracy as the first wireless control signal based on the first wireless control signal; means for frequency-converting the plurality of wireless signals based on the first reference signal Means for combining the plurality of frequency-converted radio signals to generate a combined signal; a transmission path for transmitting the combined signal; and a plurality of frequency-converted divided transmission transmitted signals. Means for automatically generating a second radio control signal, which is a radio control signal of any of the plurality of radio signals subjected to frequency conversion, and the second radio control signal based on the second radio control signal. 2 wireless control signals and Means for generating a second reference signal having substantially the same frequency accuracy, and means for frequency-converting the plurality of wireless signals frequency-converted based on the second reference signal to restore the plurality of wireless signals A base station, characterized in that: