CN203037853U - TDMA-based pulse pseudo-satellite transmitter - Google Patents

Abstract

The utility model relates to a pulse pseudo-satellite transmitter based on time division multiple access technology, which is composed of a pseudo-satellite, an antenna, a high-speed pulse switch device, a pulse control microprocessor and a power amplifier. The pseudo-satellite is simultaneously connected with the power amplifier and the pulse The control microprocessor is connected, the high-speed pulse switching device has two input interfaces, which are respectively connected to the power amplifier and the pulse control microprocessor, the antenna is connected to the high-speed pulse switching device, the pseudolite provides navigation and positioning signals, and the antenna transmits and outputs the navigation signal, the antenna is controlled by a high-speed pulse switch device, the pulse control microprocessor controls the action of the high-speed pulse switch device, and the pulse control microprocessor completes the status verification of the pseudolite, and generates a 7% duty cycle when the pseudolite is working normally. The wave signal is sent to the high-speed pulse switching device. Compared with the traditional transmitter, the utility model has the characteristics of simple structure, small interference and high precision.

Description

A Pulsed Pseudo-Satellite Transmitter Based on Time Division Multiple Access Technology

technical field

The utility model relates to a pulse pseudo-satellite transmitter, in particular to a pulse pseudo-satellite transmitter based on time division multiple access technology.

Background technique

Pseudo-satellite signal transmission pulse power is usually so strong that it will exceed the dynamic range of the receiver. When the receiver is saturated by a strong signal, the weaker satellite signal and noise will disappear at the output of the correlator, so the pseudo-satellite When the satellite is transmitting the navigation pulse signal, it will interfere with the normal reception of the satellite signal in orbit. When the receiver is saturated due to the pseudolite pulse signal, the satellite signal will be completely blocked. When designing the pseudolite pulse signal transmission method, the impact of pulse saturation on pseudolite and satellite signals must be carefully considered.

The power of the satellite navigation signal to reach the user equipment is relatively low, and it is easily interfered by the pseudolite. The anti-jamming problem of the satellite navigation signal is a key issue in the field of pseudolite navigation. Like other communication systems, satellite navigation signals mainly have three anti-jamming methods: time domain, air domain and frequency domain, all of which require related calculations and complex hardware equipment. Pseudo-satellite systems often use pulse signal blanking technology to reduce interference to satellite signals in orbit. This design idea is to turn off the receiver’s on-orbit satellite signal correlator during the pseudo-satellite pulse. The correlator does not work, and the pseudo-satellite signal Interference will not enter the receiving channel of the satellite signal in orbit. The blanking signal needs to be obtained by a saturation monitor in the receiver RF circuit. When the pseudolite pulse signal is transmitted, the blanking signal disappears, the on-orbit satellite signal correlator of the receiver is turned on, and the receiver receives the on-orbit satellite signal.

At present, the traditional pulse signal blanking mainly has the following problems:

① Pseudo-satellite pulse transmission time needs to turn off the on-orbit satellite signal correlator of the receiver;

② RF equipment needs to have channel saturation detection capability, and provide silencer signal to blanking circuit;

③ A blanking circuit is required to control the on-off of the satellite signal channel of the receiver;

④ The pulse transmission time is very short, usually on the order of nanoseconds, so the sensitivity of the blanking circuit is very high;

⑤ The blanking circuit needs to work repeatedly and reliably, and needs to have high frequency response characteristics.

Contents of the invention

In order to solve the technical problems in the prior art, the utility model provides a pulse pseudo-satellite transmitter capable of simultaneously receiving pseudo-satellite signals and in-orbit satellite signals based on time-division multiple access technology.

The technical scheme of the utility model is as follows: a pulse pseudo-satellite transmitter based on time division multiple access technology is composed of a pseudo-satellite, an antenna, a high-speed pulse switch device, a pulse control microprocessor and a power amplifier, and the pseudo-satellite is simultaneously connected with the power amplifier and the power amplifier. The pulse control microprocessor is connected, the high-speed pulse switching device has two input interfaces, which are respectively connected to the power amplifier and the pulse control microprocessor, the antenna is connected to the high-speed pulse switching device, the pseudolite provides navigation and positioning signals, and the antenna transmits output The navigation signal and the antenna are controlled by the high-speed pulse switching device. The pulse control microprocessor controls the action of the high-speed pulse switching device. The pulse control microprocessor completes the status verification of the pseudolite, and generates a 7% duty cycle when the pseudolite is working normally. The square wave signal is sent to the high-speed pulse switching device.

The utility model has the following characteristics:

1. The receiver simultaneously receives signals from pseudolites and in-orbit satellites;

2. Use time division multiplexing to transmit pseudolite pulse signals;

3. The pulse control microprocessor generates a square wave pulse signal;

4. The duty cycle of pseudolite pulse signal transmission is 7%;

5. The signal-to-interference ratio (S/I) of the receiver is not less than 6dB.

The beneficial effects of the utility model are:

1. The utility model generates a square wave pulse signal with a duty cycle of 7% through the pulse control microprocessor, which is at a high level during the 7% pulse time, and the high-speed pulse switch device is turned on, and the navigation signal is transmitted to the antenna, and the navigation terminal user It can receive the navigation signal of the pseudolite for navigation and positioning, and the pseudolite transmitting antenna does not transmit any signal outside the pulse time, which avoids interference to the terminal user's reception of the satellite in orbit due to the strong pseudolite navigation signal.

2. The 7% pulse duty cycle required by the technical requirements of the utility model is less than the 10% duty cycle recommended by the RTCM-104 committee. Pseudolites only interfere with the receiver's tracking of satellite signals in orbit when they transmit pulsed signals, so in each cycle, only 7% of the time will interfere with the receiver's reception of satellite signals. In this case, most existing receivers can simultaneously track pseudolite signals and satellite signals in orbit. In the stage of pseudolite pulse signal transmission, the interference time to the satellite signal in orbit is limited, it will not cause great interference to the capture of satellite signal in orbit, and it will not cause long-term channel saturation of the receiver and cause the receiver to lose the satellite signal. Lock.

3. The technology of controlling the duty cycle of the pseudolite pulse signal transmission to 7% can reduce the satellite navigation terminal receiver's need for satellite channel blanking during the pseudolite pulse signal transmission time. The 7% duty cycle can realize the reliable reception of civilian pseudolite navigation signal frequency band, and at the same time improve the reliability of on-orbit satellite signal reception when multiple pseudolites work at the same time, so that the 20% pseudolite pulse signal that the receiver can tolerate Pseudolites increase in duty cycle range.

4. The receiver does not need to add a blanking circuit for the satellite signal receiving channel. Most ordinary receivers with S/I not less than 6dB can simultaneously receive pseudolites and in-orbit satellite signals, using no more than three pseudolites Satellites assist in-orbit satellites to achieve precise positioning. Usually, the positioning accuracy of pseudolite-assisted positioning can reach centimeter-level accuracy.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described:

A pulsed pseudolite transmitter based on time division multiple access technology, composed of pseudolite 1, antenna 2, high-speed pulse switch device 3, pulse control microprocessor 4 and power amplifier 5, pseudolite 1 simultaneously with power amplifier 5 and pulse The control microprocessor 4 is connected, the high-speed pulse switching device 3 has two input interfaces, which are respectively connected to the power amplifier 5 and the pulse control microprocessor 4, the antenna 2 is connected to the high-speed pulse switching device 3, and the pseudolite 1 provides navigation The positioning signal, the antenna 2 transmits and outputs the navigation signal, the antenna 2 is controlled by the high-speed pulse switch device 3, the pulse control microprocessor 4 controls the action of the high-speed pulse switch device 3, and the pulse control microprocessor 4 completes the status verification of the pseudolite 1, and the When the satellite 1 is working normally, it generates a square wave signal with a duty ratio of 7%, which is sent to the high-speed pulse switching device 3 .

The pulse pseudolite transmitter performs clock synchronization with the pseudolite 1 through the pulse control microprocessor 4 to ensure that the start of the pulse signal is synchronized with the start of the signal period of the pseudolite 1 . The pulse control microprocessor 4 detects the operating state of the pseudolite 1. Under the normal state of the pseudolite 1, a square wave pulse with a duty ratio of 7% is generated, which is high level in the pulse period and is at other times. low level. The on-off of the high-speed pulse switch device 3 is controlled by the pulse signal. During the high-level time, the high-speed pulse switch device 3 is turned on, and the navigation signal of the pseudolite 1 is sent to the antenna 2 for transmission after passing through the power amplifier 5 . Outside the pulse high level period, the high-speed pulse switching device 3 is turned off and does not send any signal to the antenna 2 .

During the satellite signal period, the pulse control microprocessor 4 gives the pseudolite 1 a time slot with a specified 7% duty cycle through the high-speed pulse switching device 3, and the pseudolite 1 uses the same carrier frequency to send to the user equipment in this time slot For the navigation message, different pseudolites 1 have different time slots for entering the satellite signal cycle, and these navigation message signals are arranged in chronological order to form the pseudolite navigation message.

The pulse pseudolite transmitter controls the high-speed pulse switch device 3 through different time slots to complete the navigation signal time-division multiplexing mechanism, so that the pseudolite 1 can work normally without affecting the terminal equipment to receive satellite signals in orbit.

Claims (1)

1. a kind of pulse pseudolite transmitter based on time division multiple access technology is made up of pseudolite, antenna, high-speed pulse switching device, pulse control microprocessor and power amplifier, is characterized in that: described pseudolite simultaneously and power amplifier It is connected with the pulse control microprocessor. The high-speed pulse switching device has two input interfaces, which are respectively connected with the power amplifier and the pulse control microprocessor. The antenna is connected with the high-speed pulse switching device. The pseudolite provides navigation and positioning signals, and the antenna transmits Output the navigation signal, the antenna is controlled by the high-speed pulse switch device, the pulse control microprocessor controls the action of the high-speed pulse switch device, the pulse control microprocessor completes the status verification of the pseudolite, and generates a 7% duty cycle when the pseudolite is working normally The square wave signal is sent to the high-speed pulse switching device.