JPS62176232A - Multiplex transmission system - Google Patents

Abstract

PURPOSE:To prevent crosstalk of narrow band information by using a special code so as to apply spectrum diffusion to narrow band information within a band of broad band information. CONSTITUTION:The broad band information from an input terminal 11 and the narrow band information from an input terminal 12 modulate a carrier from an oscillator 13 by modulators 201, 202. The signal is subjected to band spread by a spectrum diffusion modulator 203, a synthesizer 204 synthesizes the result and the synthesized signal is sent from a transmitter 205. A reception station 250 uses a receiver 251 to receive the signal, a distributor 252 branches the signal, a spectrum diffusion demodulator 253 applies the inverse diffusion, an interference eliminating circuit 254 eliminates the broad band information of a demodulator 255 and a demodulator 256 demodulates the narrow band information.

Description

Detailed Description of the Invention "Industrial Application Field" This invention is a method for receiving one wideband information transmitted from one or more transmitting stations using one carrier frequency and one or more narrowband information using one carrier frequency. This relates to the multiplex transmission system received at the station.

"Prior Art" As a conventional method of this type, the method shown in FIG. 7 has been used. At the transmitting station 100, wide-scale information having a band of fw from the terminal 11 (FIG. 8A) is passed through a high-pass filter 101.
As shown in FIG. 8B, the low frequency band of fN is cut off, and this and the narrow band information (for example, control information) having the band of rN from the terminal 12 are combined by the synthesizer 102 to obtain the eighth signal. Figure C (=signal shown.This synthesized band 0-f
The carrier wave of flF from the oscillator 13 is transmitted to the modulator 1 using the signal W.
03, and the modulated output is transmitted by the transmitter 104 as an fRF radio carrier wave shown in FIG.

In the receiving station 150, a receiver 151 receives an fRF radio carrier wave, and a demodulator 152 demodulates it into a baseband signal as shown in FIG. 8E. The demodulated signal is sent to the distributor 15
3, one of the distributed signals is filtered through a high-pass filter 154 to extract only the higher frequency components than fN as shown in FIG. Another distribution signal is passed through the low-pass filter 155.
(From 2, as shown in FIG. 8G, only the low frequency components below 2 fN are extracted and outputted to the output terminal 15 as narrow band information.

In such a configuration, wideband information is effective if it is not affected greatly by the information, like analog audio information (= even if there is no low frequency component), but like digital information (
This method cannot be applied in cases where information cannot be reproduced accurately without the two low-frequency components. However, there is a method that combines narrowband information with the outside of the upper band of wideband information so that the wideband information can be reproduced accurately even as digital information, but with this method, the spectrum in the wireless band is widened, and in other words, the wideband transmitting and receiving device Also, one transmitting station transmits both broadband information and narrowband information, and one or more other transmitting stations transmit only narrowband information using the same radio carrier. In this case, there was a drawback that narrowband information caused interference.

``Means for Solving the Problems'' This invention spreads the spectrum of narrowband information within the band of wideband information using a specific code, combines the spread spectrum signal with wideband information, and transmits the combined signal to a radio carrier. Send by signal. Receive and demodulate the transmitted signal, divide the demodulated output into two, and output one of the two as broadband information,
The other is spread spectrum demodulated to obtain narrowband information output.

In this way, wideband information is available even in the case of digital information, and it is also possible to transmit one wideband information and several narrowband information from one or more transmitting stations to a receiving station using one radio carrier. becomes.

"Embodiment" FIG. 1 shows an embodiment of the present invention. In the transmitting station 200, wideband information having a band of fw from the input terminal 11 (FIG. 2A) and narrowband information having a band of fN from the input terminal 12 (FIG. 2B) are generated from the oscillator 13. The flF carrier waves are modulated by modulators 201 and 202, respectively. The narrowband information shown in the second diagram output from the modulator 202 is
The spreading code spreads the band to the same extent as the band of broadband information in the spread spectrum modulator 203 (FIG. 2E).

The band-spread output signal from the spread spectrum modulator 203 and the broadband information output from the modulator 201 are combined by a combiner 204 as shown in FIG.

The synthesized signal is sent to fRF by transmitter 205.
The signal is transmitted as a signal shown in FIG. 2G (2) on a radio carrier wave.

In the receiving station 250, a receiver 251 receives an fRF radio carrier wave, and lowers the carrier wave to two flF as shown in FIG. The demodulator 255 demodulates the signal, obtains the broadband information shown in the second factor, and outputs it to the output terminal 14.At this time,
Since narrowband information is spread spectrum, its power density is low and it is just noise, so it has almost no effect on wideband information. The other distribution signals are demodulated by the spread spectrum demodulator 253 using the spread code used by the spread spectrum modulator 203 of the transmitting station to obtain a signal as shown in 5-2nd factor J. Since this demodulated output j2 is also combined with a wideband signal, the interference of the wideband information is removed by the interference cancellation circuit 254.
The output of this interference cancellation circuit 254 is sent to the demodulator 2.
56 to obtain narrowband information shown in the second diagram and output it to the output terminal 15.

When there is a plurality of pieces of narrowband information to be transmitted, for example, as shown in FIG. The modulated output is band-spread by a spread spectrum modulator 206 using a spreading code. In this case, the spreading code is different from that of the spread spectrum modulator 202, and the spread band is approximately the same as the output wideband information of the modulator 201. The output 17 of the modulator 201 and the outputs 18 and 19 of the spread spectrum modulators 203 and 207 are combined into a synthesizer 2.
In step 04, they are synthesized as shown in FIG.

At the receiving station 250, the splitter 252 divides the signal into three parts, one of which is demodulated by the spread spectrum demodulator 257 using the spreading code used by the spread spectrum modulator 20'7, and the broadband information component is interfered with from the demodulated output. It is removed by a removal circuit 259, and its output is demodulated by a demodulator 259 and sent to the input terminal 16.
The narrowband information corresponding to the narrowband information of is obtained at the output terminal 21. The rest is the same as in the case of FIG.

In this way, the transmitting station 200 is equipped with a modulator and a spread spectrum modulator, and the receiving station 250 is equipped with a spread spectrum demodulator.
By adding multiple sets of interference cancellation circuits and demodulators and using different spread spectrum codes for each narrowband information, the receiving station demodulates desired narrowband information for each spread code.

With this configuration, wideband information can be transmitted as is without cutting off the low frequency range.

Even when the broadband information is digital information.

Multiplex transmission with narrowband information is possible without preparing a wideband transmission/reception system. Furthermore, by using a plurality of spread spectrum codes, it becomes possible to multiplex and transmit narrowband information 1, such as low bit rate data and control information, of different relatives into wideband information.

FIG. 5 shows still another embodiment of the present invention, in which parts corresponding to those in FIG.

In this example, a transmitting station 400 provided in addition to the transmitting station 200
(In case 2, the broadband information is not transmitted, and only the narrowband information (M in FIG. 6) from the input terminal 22 is sent to the fIF by the modulator 402.
The carrier wave is modulated, and the output thereof is spread spectrum modulated in the spread spectrum modulator 403 using a spreading code different from that used in the spread spectrum modulator 203 (N in FIG. 6), and the spread spectrum output is transmitted to the synthesizer 4.
04. It is transmitted using an fRF radio carrier wave through the transmitter 405 (O in FIG. 6).

In the receiving station 250, the transmitting wave from the transmitting station 200 and the transmitting wave from the transmitting station 400 are received by the receiver 251. The reception output (M in FIG. 6) is the same as when receiving a signal (fourth case) in which wideband information from one transmitting station and multiple narrowband information are multiplexed.

Similar to the receiving station 250 in FIG. 3, the received signal whose carrier wave has been lowered is distributed by a distributor 252, and one of the signals is demodulated by a demodulator 255 to provide wideband information (see FIG. 6). The other two distributed signals are spread spectrum modulators 202 and 4.
Demodulated by spread spectrum demodulators 253 and 257 using the spreading codes used in 02 and 02, respectively.
P), the respective demodulated outputs are sent to interference cancellation circuits 254 and 25.
8 to remove broadband information interference, and the demodulator 25
6.259 and narrowband information (Fig. 6K).

Q).

Because of this configuration, even if a station that transmits broadband information and a separate station that transmits only narrowband information use the same frequency to transmit information, the receiving station will not receive the broadband information. It becomes possible to reproduce each of a plurality of pieces of narrowband information.

Furthermore, by time-divisionally transmitting narrowband information from a station transmitting narrowband information, the receiving station's narrowband information reproducing system (spread spectrum demodulator, interference cancellation circuit, demodulator) can It is also possible to reproduce narrowband information from the transmitting station.

"Effects of the Invention" As explained above, according to the present invention, even when the broadband information is digital information, multiplex transmission of broadband information and narrowband information is possible without using a broadband transmitting/receiving device. The receiving station has the advantage of being able to reproduce multiple types of information by receiving only one frequency. Furthermore, if the narrowband information is used as control information for the receiving station, it is also possible to receive control information (narrowband information) from another station while wideband information is being received.

This invention is as small as a mobile phone.

In order to reduce the number of light vehicles, systems that require communication information (broadband information) and control information (narrowband information) to be transmitted and received using one transceiver, that is, one radio carrier wave.
Can be applied in two ways. In addition, in mobile communications, since a single mobile device can receive control information (zone identification information, etc.) for adjacent wireless zones even during communication, it is possible to compare the electric field strength of the control signals in each zone (secondarily, it is possible to detect the position of a mobile object). It is possible and
It is also effective for switching zones during communication and switching channels during communication.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram explaining the present invention in detail, Fig. 2 is a diagram showing the power density spectrum at each part in Fig. 1, and Fig. 3 is a circuit diagram explaining another embodiment of the invention. , FIG. 4 is a diagram showing the power spectrum of the output of the synthesizer 204 in FIG. 3, FIG. 5 is a circuit configuration diagram illustrating still another embodiment of the present invention, and FIG. Fig. 7 is a circuit configuration diagram showing conventional multiplex transmission of wideband information and narrowband information, and Fig. 8 shows the power density spectrum of each part in Fig. 7. It is a diagram. 200.400: Transmitting station, 201.202. 401.402: Modulator, 203,403 spread spectrum modulator, 204.404: Combiner, 205.4
05: Transmitter, 250: Receiving station, 251: Receiver, 25
2: Distributor, 253°257 = Spread spectrum demodulator, 25 = 1. 258: Interference cancellation circuit, 255, 256, 259 = demodulator, fIp: intermediate carrier frequency, fRF: black line carrier frequency. Patent applicant: Nippon Telegraph and Telephone Corporation Agent: Taku Kusano A
E3 E F 2 Diagram CD G H K L Wood 6 A B M N Li fN CD OH p K

Claims (2)

[Claims] (1) In a method of multiplexing broadband information and narrowband information and wirelessly transmitting the same, a spread spectrum modulator that spreads the spectrum of narrowband information using a specific code in a band comparable to the band of the broadband information; A transmitting station that has a combiner that combines the output of the spread spectrum modulator and the broadband information, and a transmitter that sends the output of the combiner to the radio section, and a receiver that receives the transmission signal of the transmitting station. and a receiving station having a distributor that distributes the output of the receiver, and a spread spectrum demodulator that demodulates one of the outputs of the distributor with a specific code of the transmitting station, A multiplex transmission system characterized in that the wideband information is obtained from one output of the distributor, and the narrowband information is obtained from the output of the spread spectrum demodulator. (2) Narrowband information from another transmitting station of the transmitting station is spread spectrum modulated in a band comparable to the wideband information using a code different from the specific code, and the spread spectrum modulation output is spread spectrum modulated at the same frequency as the transmitting station. 2. The multiplex transmission system according to claim 1, wherein each of the narrowband signals is obtained by transmitting using a carrier wave and spread spectrum demodulating the output of the receiving station distributor using each of the specific codes.