JPH01320599A - Automotive information transmission system - Google Patents

Abstract

PURPOSE:To compose the circuit of an on-vehicle equipment of an AM detector and a low pass filter when only the low bit rate data are necessary by transmit ting high bit rate data by means of amplitude modulation and adding the low bit rate data. CONSTITUTION:High bit rate data 6 are amplitude-modulated by an amplitude modulator 5 in a road station, low bit data 8 are added by an adder 7, and the said signals are amplitude-modulated by amplitude modulator 9. In the on vehicle equipment to receive the signal, an AM detector 13 removes a carrier, a band pass filter 15 and an AM detector 16 take out the data at the high bit rate, and supply them to a signal processing part 17. The data at the low bit rate are separated by a low pass filter 18, and supplied to the processing part 17. In such a simple circuit constitution, the high bit rate data can be separated from the low bit rate data, and when the on vehicle equipment only requires the single piece of the information, it can be inexpensively realized.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention is a method for transmitting position/d information, traffic information, messages, images, etc. from roadside stations installed at various places on the road to vehicles traveling on the road. This relates to a news transmission system for automobiles.

Conventional technology Conventionally, in an automobile news transmission system, one 11
There was no system for transmitting low bit rate data and high bit rate data from the S upper station, and low bit rate data such as location information and traffic information was transmitted using FM modulation.

Furthermore, when transmitting low bit rate data and high bit rate data at the same time, a method has been used in which the amount of information is small and FM modulation is performed at a high bit rate, even though low bit rate transmission is possible.

However, in the two-phase conventional example, the problem that the invention aims to solve is
If the N information is data with only a low bit rate, it has the disadvantage that the on-vehicle device becomes expensive.

The present invention uses subcarriers to perform amplitude modulation for large amounts of information (b) data, adds data to data that requires a small amount of information, and further amplitude modulates each item to transmit. On the other hand, if all you need is low bit rate news, the receiving section of the on-vehicle device should be an AM detector and an amplifier.
It can be constructed with only one filter and 10-pass filters, and a safe system can be provided.

In order to achieve the above object, the present invention transmits both high bit rate information such as messages and images and low bit rate information such as location information and traffic information from one roadside station. In this case, the high bit rate data is amplitude modulated and the low bit rate data is added, and the on-the-road station uses a swing/sing modulator, low-beam,
The structure consists of an adder for adding the l-V-t data, a single-station transformer A for amplitude modulating the above signal, and an in-vehicle device for receiving the above radio wave, which removes the carrier. (F-pass filter and AM detector, and extracting low bit rate data. It consists of a low-pass filter for the purpose.

Effects of the present invention +ri By having the above configuration, especially in an on-vehicle device, if the low-speed signal is only low bit rate data, an AM detector is used to remove the carrier, and a low pass is used to extract the low bit rate data. If there is a filter, it is possible to supply data to the signal processing section, and the in-vehicle device can be realized with a simple circuit configuration.

EXAMPLE An example of the present invention will be described below. This example (
As shown in Figure 1, the antenna 2 of the roadside station 1 transmits information such as location information, traffic information, messages, images, etc. to the vehicles 3 traveling on the tower in the wireless zone.
It's Sudem.

FIG. 2 shows the configuration of the roadside station of the Egi embodiment.

In FIG. 2, 4 is a subcarrier generator for generating subcarriers, 5 is an amplitude modulator for modulating high bit rate data 6, and 7 is for adding low bit rate data 8. 9 is a modulator for amplitude modulating the signal passed through the adder 7, 10 is a carrier generator, and 11 is an antenna for radiating the signal.

On the other hand, FIG. 3 shows the configuration of an on-vehicle device for receiving the above signal in a vehicle. In FIG. 3, 12 is an antenna for receiving radio waves radiated from a roadside station, 13 is an AM detector for removing carriers, and 14 is an amplifier for amplifying the detected signal. 16 and 16 are high bit rate data'&! Extraction--A bandpass filter and AM detector 18 are used to take out the low bit rate data.

As in 1, at an on-the-road station, the high bit rate data 6 is modulated by the vibration/seat modulator 6, the low bit rate data 8 is added by the adder T, and the above signal is modulated by the vibration modulator 9. swing 1
By performing OA modulation, the configuration of the on-vehicle device that receives this signal changes to OA to remove the carrier, as shown in Figure 3.
The M filter 13 transfers high bit rate data to the signal processing unit 1.
7, an AM filter 416, and a low-pass filter 18 for extracting low pit-ray i data. This can be realized at low cost, especially when only one of the information is required for the in-vehicle device.

Effects of the Invention The present invention has the above-mentioned configuration, and in particular, the IF or machine side value;
Point Bi1. If you only need information on one of the trays (, BooP, ``B'', or Trade data), it can be realized at a low cost.In particular, if you only need low bit rate data, the necessary data is the 3rd one. As is clear from the figure, M, * wave generator, and amplifier.

This can be realized with a circuit configuration consisting of only a low-pass filter.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the automotive information transmission system of the present invention, Fig. 2 is a block diagram of a roadside station of the automotive information transmission system according to an embodiment of the invention, and Fig. 3 is an in-vehicle installation of the same embodiment. FIG. 2 is a block diagram of the machine. 1...Road station, 2...Antenna, 3...
-Car, 4...Subcarrier generator, 6...Content modulator, 6...High bit rate data, 7...--
Adder, 8...Low bit rate data, 9...
...Amplitude modulator, 1o...Carrier generator, 1
1...Antenna. 12...Antenna, 13...MuM detector, 14
... Seat multiplier, 15... Bandpass filter, 16...
...MuM filter, 1 completed...Signal processing section, 1
8...Low pass filter. Name of agent: Patent attorney Toshio Nakao and 1 other person/c'q u

Claims (1)

[Claims] a subcarrier generator for generating subcarriers;
A first amplitude modulator modulated by high bit rate data necessary for transmitting messages, images, etc. and a summing device for adding together low bit rate data necessary for transmitting position information, traffic information, etc. a second amplitude modulator for amplitude modulating the signal passed through the adder, a carrier generator for generating a carrier, and an antenna for radiating the signal, An AM detector for removing the carrier component of radio waves radiated from the above road station, an amplifier for amplifying the signal detected by the AM detector, and a bandpass filter for extracting only the high bit rate data component. , an AM for detecting the signal that has passed through this bandpass filter and transmitting the data to the signal processing section.
An information transmission system for an automobile comprising an on-vehicle device including a detector and a low-pass filter for extracting low bit rate data and transmitting the data to the signal processing section.