CN110266326B

CN110266326B - OOK-based one-wire communication radio frequency front end control method and system

Info

Publication number: CN110266326B
Application number: CN201910530966.9A
Authority: CN
Inventors: 荣元政; 刘波; 田非凡
Original assignee: Xinglian Xintong Dongguan Communication Technology Co ltd; Chengdu Xinglian Xintong Technology Co ltd
Current assignee: Xinglian Xintong Dongguan Communication Technology Co ltd; Chengdu Xinglian Xintong Technology Co ltd
Priority date: 2019-06-19
Filing date: 2019-06-19
Publication date: 2021-07-13
Anticipated expiration: 2039-06-19
Also published as: CN110266326A

Abstract

The invention relates to a one-wire communication radio frequency front end control method based on OOK, which respectively modulates radio frequency front end TTL control signals output by a baseband scheduling unit on different carrier frequencies in an OOK mode; the radio frequency front end separates the modulated signals through a filter bank, and then the signals are sent to an OOK demodulator to demodulate the signals respectively to obtain corresponding control signals, and the radio frequency front end controls corresponding unit circuits. The scheme can realize the control of a plurality of quick response control signals, and the control signals are mutually independent, such as receiving-transmitting duplex (T/R) control, receiving channel control (LNA _ EN), transmitting channel control (PA _ EN) and the like; the control signal is based on the baseband scheduling unit, is irrelevant to receiving and transmitting radio frequency signals, is not influenced by signal bandwidth, power and the like, has good universality and is suitable for different communication systems; the control signal has the characteristics of small time delay and time delay jitter, and simultaneously supports the adoption of a baseband scheduling unit for time delay compensation; the binary on-off keying control circuit is simple to implement, low in cost and low in power consumption.

Description

OOK-based one-wire communication radio frequency front end control method and system

Technical Field

The invention relates to the field of communication, in particular to a one-wire communication radio frequency front end control method and a system based on OOK.

Background

In modern mobile communication system terminals, in order to respond to energy-saving and environment-friendly strategies, requirements on energy consumption of the terminals are becoming stricter, and especially in mobile terminal equipment which is powered by batteries and has limited size and capacity of the batteries, the energy consumption determines the duration of the whole machine, and meanwhile, the usability and the usability of the terminals are also directly influenced. In order to meet the requirement of energy saving, a terminal usually performs real-time adjustment according to a service requirement to determine to turn on or off a radio frequency front end, a radio frequency channel, a baseband hardware accelerator, a baseband soft processing unit and other functional units so as to achieve low power consumption and energy saving of each stage of module, a scheduling unit obtains scheduling control parameters according to a protocol according to a baseband processing unit to complete low power consumption scheduling of each functional module, and a functional block diagram is shown in fig. 1.

In view of the characteristic that a Time Division Multiple Access (TDMA) system transmits and receives according to time slots is better for understanding of control scheduling, the TDMA system is taken as an example for explanation. The TDMA system terminal determines that the terminal completes the receiving and transmitting of signals in corresponding time slots according to the distribution condition of system resource time slots (the receiving and transmitting time slots can be overlapped or have intervals, which depends on the frequency division multiplexing or time division multiplexing of the receiving and transmitting multiplexing mode of the system and the terminal), the receiving and transmitting are relatively independent, namely, when receiving idle time slots, the corresponding radio frequency front end receiving Low Noise Amplifier (LNA), the radio frequency receiving channel and the baseband receiving processing unit all need to process a low power consumption state; similarly, when transmitting idle time slot, the corresponding radio frequency front end Power Amplifier (PA), radio frequency transmission channel and baseband transmission processing unit should be in low power consumption state.

In the conventional communication terminal, the baseband processing unit, the radio frequency channel unit and the radio frequency front end unit are integrated together in Printed Circuit Board (PCB) level, chip level, software logic control and other manners, so that the control of each unit by the scheduling module is easily realized. However, in some terminals that need to adapt to remote application scenarios, the rf front end needs to be used at a longer distance from the terminal host. In order to facilitate the use of users and reduce the connection between devices during use, a radio frequency coaxial cable is often used for connection, namely, a wire harness.

As disclosed in chinese patent No. CN109217830A, a radio frequency power amplifier switch control circuit, a radio frequency front end transmitting link and a receiving link, a radio frequency coaxial cable needs to transmit radio frequency transceiving signals, a dc power supply, a carrier communication signal, etc. at the same time. The carrier communication signal transmits the serial port command parameter through a carrier modulation technology, so that the on-line configuration of the radio frequency front-end parameter is realized. The direct current power supply is transmitted through a radio frequency cable in a power supply feeding mode and is used for supplying power to radio frequency front-end equipment, so that low-frequency (near direct current) TTL logic control signals such as a receiving and transmitting control (T/R), a low-noise amplification time-delay energy (LNA _ EN) and a power amplification enabling energy (PA _ EN) can not be transmitted at the same time. Although the control of low power consumption of the radio frequency front end can be realized through carrier communication control instructions, power off and a signal-based detection scheme adopted in CN109217830A, the control has certain defects or non-optimal schemes.

According to the communication instruction control scheme, when the low-power consumption control of the radio frequency front end is realized through the carrier communication control instruction, due to the fact that the serial port instruction is transmitted in a carrier modulation mode, the communication instruction control scheme has large time delay and cannot be used for terminals with 10 us-level and faster time response requirements. Taking the simplified and fast 1-byte serial port control as an example, the serial port baud rate is set to 115200, and the transmission duration is as follows:

the above time is only the time required for transmitting the byte data, and does not include the processing time delay for analyzing and processing the data by the processor, and when the communication instruction is actually used, the communication instruction needs to complete a plurality of functions, such as receiving gain setting and query by the radio frequency front end, sending gain setting and query, temperature query by the radio frequency front end, output power query by the radio frequency front end power amplifier, power amplification state of the radio frequency front end, and attitude (azimuth and pitch) of the radio frequency front end antenna, so that when the communication instruction is actually realized, a formatted communication protocol is usually adopted for control, the length of the protocol data is as long as 16 bytes or even hundreds of bytes, the control time delay is longer, and when the processor analyzes the instruction, the processor is affected by other software functions of the processor, a larger time delay jitter may be generated, which is not beneficial to the baseband scheduling unit to send a control signal in advance by adopting a time compensation, also, large power consumption is generated, and thus, the method is not suitable for low-power consumption real-time control of the radio frequency front end;

turning off the power scheme; powering down schemes can achieve very low power consumption, but also can cause a very serious problem — inability to receive signals. Because the single radio frequency coaxial cable is adopted for feeding power, the receiving and the transmitting can not be controlled independently, so that the receiving channel can not work normally after the power supply is closed, the terminal can only initiate the service actively but can not receive the service passively, even in most systems needing to receive synchronization and broadcast information, the terminal exits from the network, and the functional service of the terminal is seriously influenced, so the application of the scheme is extremely limited;

the scheme based on signal detection in CN 109217830A. The scheme is mainly used for detecting the transmitted signal to control the low power consumption of the power amplifier, and usually, the power amplifier circuit is a main energy consumption part of the radio frequency front end, so that the power consumption of the whole radio frequency front end can be greatly improved. However, this solution still has more disadvantages:

(1) only the transmission channel can be controlled, and other controls such as the reception channel and the T/R control cannot be realized. Generally, the carrier-to-noise ratio of the received signal is low, and the bandwidth of the received signal is the whole system frequency band and much larger than the actual signal bandwidth, so that the received signal is usually submerged in the wideband noise and cannot be detected by a simple signal detection method, for example, in an skynet satellite mobile communication system, the bandwidth of a radio frequency front end receiving channel is 30MHz, the actual voice channel bandwidth is about 20KHz, and the carrier-to-noise ratio is about 32dB worse. In addition, since the rf front-end receiving channel can receive all channel signals in the entire system bandwidth, and cannot identify a signal that really needs to be detected, low power consumption control of the receiving channel cannot be achieved.

(2) The detection control signal has time delay and cannot be compensated by the baseband scheduling control unit. The detector control circuit generates the on and off control signals by examining the actual transmitted signal. The delay characteristics of circuits such as a detector, a comparator, an analog switch and the like influence the starting control signal of the circuit to be always later than the sending signal, so that the quality of the sending signal is influenced, and whether the sending signal can meet the requirement of a switching time template is influenced in serious cases. The transmitted signal is strictly controlled by the baseband scheduling unit and must be aligned with the system-defined time slots, so that the purpose of compensating for the associated delay cannot be achieved by simply advancing the transmitted signal.

Taking the skynet satellite mobile communication system as an example, when the highest data rate transmission is carried out, the symbol rate is about 250k/s, according to the requirement of a switch time template (see fig. 2), the burst power rise time is 2 symbol times, namely 8us, and the power state needs to be met after the burst power rise time, so the power amplifier switch response time needs to be less than 8us (including the detection circuit delay). In practical implementation, whether the requirement of the burst power rising template is met or not should be considered, so that the influence of the response time of the power amplifier switch on the burst signal should be reduced as much as possible, and the influence should be controlled within 0.5 symbol, namely 2 us.

The above example is only the requirement of the skyware satellite mobile communication system on the response delay of the control signal under the condition that the symbol rate is 250k/s, and in the communication system with the symbol rate of mega-second or even dozens of mega-second, the requirement on the control delay is more severe, and even the scheme is not applicable any more.

(3) The detection control signal delay is affected by the signal power and has the minimum requirement on the input signal power (carrier-to-noise ratio).

Due to the detection characteristic of the detector and the fixed reference threshold voltage of the rear-stage comparator, when the signal power is high, the detection output voltage exceeds the reference threshold voltage at the initial stage (such as 0.3 symbol) of burst power rise, so that the opening of the rear-stage power amplifier is controlled; however, when the signal power is small, it may be necessary to turn on the rear-stage power amplifier at the middle and rear stages (e.g. 1 symbol) of the burst power rise, so as to form different delay sizes.

When the input signal power (or carrier-to-noise ratio) is small, the output detection voltage fluctuation of the detector is small when a signal exists or no signal exists, the threshold setting is sensitive, and meanwhile, control logic errors are easily caused, so that the scheme is not applicable under the condition that the carrier-to-noise ratio of the transmitted input signal is low.

(4) The introduction of the detection control circuit still increases the power consumption of the radio frequency front end. In order to ensure the normal detection of small signals and the small detection control delay, the detection path usually needs to amplify signals to a proper power level according to the power detection range of the detector, for example, the linear detection range of the detector LT5534 in CN109217830a is about-50 dBm to-8 dBm (see fig. 3), and the amplifier N1 used in the detection path needs to be kept in a power-on working state all the time, so that the power consumption is not low, especially the amplifier.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide an OOK-based one-wire communication radio frequency front end control method, which well solves the existing related problems and meets the use requirements.

The purpose of the invention is realized by the following technical scheme:

a method for controlling a front-end radio frequency of a one-wire communication based on OOK comprises the following steps:

s100: respectively modulating radio frequency front end TTL control signals output by a baseband scheduling unit on different carrier frequencies in an OOK mode;

s200: the radio frequency front end separates the modulated signals through a filter bank, and then the signals are respectively demodulated by an OOK demodulator to obtain corresponding control signals;

s300: and controlling the corresponding unit circuit of the radio frequency front end by the obtained corresponding control signal.

Further, the carrier frequency modulating step of OOK includes:

s101: selecting a carrier frequency with the frequency of 10MHz-100MHz as an OOK carrier frequency;

s102: inhibiting OOK carrier frequency above 10MHz by adopting 4.7uH inductor;

s103: in the case where the transmission signal level range and the reception signal level range are the same, the lower frequency should be selected as much as possible.

Furthermore, in step S102, a feeding circuit with stepped suppression is used to implement power feeding, that is, an LC suppression circuit composed of one or more stages of hollow inductors (the high-frequency Q value is higher and can reach 40) and capacitors is added before the magnetic core power inductor (the high-frequency Q value is about 10, and there is a parasitic capacitor of about 0.5pF in the package) according to the frequency relationship of each radio frequency signal.

Further, the OOK carrier frequency may be directly generated using a low power crystal oscillator.

Further, the corresponding control signals include, but are not limited to, a duplexer control signal T/R ', a low noise amplifier control signal LNA _ EN ', and a power amplifier control signal PA _ EN ', and other front-end control signals, except for the above signals.

A system of a one-wire-through radio frequency front end control method based on OOK is composed of a radio frequency front end unit, a radio frequency one-wire-through unit and a baseband processing unit;

the radio frequency front end unit comprises an antenna, a duplexer, a power amplifier, a low noise amplifier, a multi-path OOK demodulator and a front end filter bank;

the radio frequency one-wire pass unit comprises a rear-end filter bank and a plurality of paths of OOK modulators;

the baseband processing unit comprises a radio frequency transceiving channel, a scheduling module and a baseband digital processing module;

the dispatching module respectively modulates the output radio frequency front end TTL control signals on different multi-path OOK modulators in the radio frequency one-wire pass unit to obtain modulation signals;

the modulation signal is transmitted to a front-end filter bank through a back-end filter bank;

the front-end filter bank separates the modulation signals to obtain corresponding control signals for controlling the duplexer, the power amplifier and the low-noise amplifier.

Further, the multiple OOK modulators have different carrier frequencies.

Further, the baseband digital processing module is used for performing information interaction with an upper layer application.

Further, the scheduling module is further configured to control the radio frequency transceiving channel to complete information interaction with the power amplifier and the low noise amplifier.

The invention has the beneficial effects that:

(1) the control of a plurality of quick response control signals can be realized, and the control signals are mutually independent, such as receiving-transmitting duplex (T/R) control, receiving channel control (LNA _ EN), transmitting channel control (PA _ EN) and the like;

(2) the control signal is based on the baseband scheduling unit, is irrelevant to receiving and transmitting radio frequency signals, is not influenced by signal bandwidth, power and the like, has good universality and is suitable for different communication systems;

(3) the control signal has the characteristics of small time delay and time delay jitter, and simultaneously supports the adoption of a baseband scheduling unit for time delay compensation;

(4) the binary on-off keying control circuit is simple to implement, low in cost and low in power consumption.

Drawings

Fig. 1 is a schematic diagram of scheduling control in a prior art communication terminal;

FIG. 2 is a prior art burst switch power time template;

FIG. 3 is a prior art LT5534 output voltage versus RF input power curve;

FIG. 4 is a block diagram of OOK-based RF front-end control;

FIG. 5 is a block diagram of OOK modulation principles;

FIG. 6 is a waveform diagram of an OOK modulated signal;

FIG. 7 is a schematic diagram of simulation of the influence of DC feed on the reflection coefficient of an input port;

FIG. 8 is a simulation result of the influence of DC feed on the reflection coefficient of the input port;

FIG. 9 is a schematic diagram of simulation of influence of stepped feed on input port reflection coefficient;

FIG. 10 shows simulation results of the influence of stepped feeding on the reflection coefficient of the input port;

FIG. 11 is a schematic view of a portable terminal for relaxing bowels;

FIG. 12 is a simulation diagram of OOK partial RF filter circuit;

FIG. 13 shows simulation results of OOK partial RF filter circuits;

FIG. 14 is a circuit diagram of a "one wire" RF section of the terminal host;

FIG. 15 is a circuit diagram of a "one wire" portion of the RF front end of the terminal antenna;

FIG. 16 is a "one-wire" OOK modem test waveform.

Detailed Description

The technical solution of the present invention is further described in detail with reference to the following specific examples, but the scope of the present invention is not limited to the following.

OOK (On-Off Keying), also known as binary amplitude Keying (2 ASK), uses a unipolar non-return-to-zero code sequence to control the On and Off of a sinusoidal carrier. The modulation schematic diagram and the signal waveform schematic diagram in the modulation process are shown in fig. 5.

As a preferred embodiment, the step of modulating the carrier frequency of the OOK includes:

s102: inhibiting OOK carrier frequency above 10MHz by adopting 4.7uH inductor;

Since each modulated control signal needs a system operating radio frequency signal and a power supply to be transmitted through one radio frequency cable, the carrier frequency of each modulated signal should be determined in consideration of the following factors.

(1) Modem delay and delay jitter

The OOK modulation and demodulation time delay and time delay jitter characteristics are influenced by the carrier frequency in addition to the switching time delay characteristics of the modulator, the time delay characteristics of the envelope detector and the time delay characteristics of the sampling decision device. As shown in fig. 6, the modulated carrier is a single-tone sine wave, the signal amplitude of the modulated carrier is periodic, the switch conducting time is random, the amplitude of the corresponding carrier signal can be any value within the amplitude range, and assuming that the demodulation decision threshold is 1/2 full amplitude, the maximum time delay from the switch conducting to the carrier reaching 1/2 full amplitude is 1/4 periods, that is, the maximum time delay is 1/4 periods

This value is also the delay jitter maximum. Taking the maximum allowed time delay of 2us as an example, the minimum carrier frequency is 125 KHz. Considering the actual envelope detector response requirement and the time delay introduced by other circuits, the carrier frequency should be selected as high as possible, and higher carrier frequencies can obtain better time delay jitter characteristics (the time delay jitter requirement can be 1/10 or even lower of the maximum time delay), so that the carrier frequency should be recommended to be not lower than 1.25 MHz.

(2) System working radio frequency signal and power supply interference avoidance

In a wireless communication system, radio frequency signals received from an antenna are usually very weak, which can be as low as-120 dBm for an antenna, and are easily interfered by other signals, although the anti-interference capability of the radio frequency signals is improved after the radio frequency signals are amplified by a post-stage Low Noise Amplifier (LNA), an appropriate OOK modulation carrier frequency still needs to be selected to ensure that the modulated signals do not cause interference on the radio frequency signals received by the communication system when passing through a line of radio frequency cable. For a transmission channel, although the transmission power is relatively large, the spurious suppression requirement on a transmission signal is usually 60 dB-80 dB, so that an improper OOK carrier frequency can also become a spurious signal during transmission, and the transmission signal does not meet the requirement of a radio frequency index. When considering the interference of the OOK carrier to the working rf signal, in addition to the need to avoid the carrier itself falling into the rf signal band, the filter characteristics are also needed to consider that each harmonic component should not fall into the rf signal band, and generally the influence of harmonics not lower than 10 order should be considered according to engineering experience. In a wire harness, a power supply is generally fed into a radio frequency cable in an inductance-capacitance (LC) feeding mode, an LC feeding circuit can realize the suppression of high-frequency signals, and the inductance needs to meet the requirement of direct current carrying capacity. However, the lower the frequency of the high-frequency signal is, the larger the inductance of the LC with the same suppression capability is, the larger the size of the LC is, and the high-frequency characteristic is deteriorated, and the inductance of the inductor with the same size is reduced, so that the high-frequency suppression capability of the inductor is reduced, the leaked high-frequency signal enters the DCDC circuit, and the DCDC circuit may be unstable in operation in severe cases, so that it is suggested to select a higher OOK carrier frequency, for example, 4.7uH inductance can be used for suppressing the OOK carrier frequency above 10 MHz.

(3) Facilitating carrier signal generation

The generation of the carrier signal may be directly generated by an oscillator according to a difference in frequency, or may be synthesized by a Phase Locked Loop (PLL), a frequency multiplier, a direct digital frequency synthesis (DDS), or the like. The frequency within 100MHz can be directly generated through a crystal oscillator, a silicon oscillator and the like, the circuit is simple, the power consumption requirement is low, and the cost is low; carrier frequencies above 100MHz typically require synthesis, are complex, consume high power, and are costly, so frequencies below 100MHz are recommended as OOK carrier frequencies.

(4) Easy signal separation and extraction

A wire-pass is used for simultaneously transmitting various signals in a frequency division multiplexing mode, and the signals are separated and extracted by adopting the combination of low-pass filters, high-pass filters, band-pass filters, power frequency dividers, circulators and the like with different cut-off frequencies. Therefore, in selecting the OOK modulation frequency, the out-of-band rejection requirements, realizability, and implementation forms (LC filters, dielectric filters, surface acoustic wave filters SAW, LTCC filters, etc.) of each filter should be fully considered.

(5) Cable loss

According to the frequency characteristics of the radio frequency cable, generally, the higher the frequency is, the greater the attenuation is, the design process is to fully estimate and evaluate the loss difference caused by different cable length requirements in different application occasions, and each signal is ensured to be in a proper transmitting and receiving level range. Therefore, when the OOK modulation frequency is selected, the lower frequency is selected as much as possible under the condition of the same transmission signal level and the same receiving signal range, so as to reduce the influence of cable loss on OOK signal demodulation in long-line application.

And combining the OOK modulation frequency selection factors, and selecting the OOK modulation frequency with a frequency combination for controlling signals in a frequency range of 10MHz-100 MHz. The low-power crystal oscillator can be selected to directly generate the carrier wave, and the realization is simple. For example, when only the control of the receiving and transmitting channels is realized, 20MHz and 40MHz may be selected as carrier frequencies of two modulation signals, and both local oscillation signals may be generated by a crystal oscillator with a size of 3.2 × 2.5mm, and the power consumption is about 5 mW.

As a preferred embodiment, in step S102, a feeding circuit with staged suppression is used to implement power feeding, that is, one or more LC suppression circuits composed of an air core inductor and a capacitor with higher high-frequency Q value and better high-frequency characteristic are added before the core power inductor according to the radio-frequency signal, so as to implement staged suppression on the high-frequency signal.

In order to realize the suppression of a circuit for feeding high-frequency signals (such as 2MHz carrier communication signals) and provide enough current carrying capacity, a power inductor and a capacitor with inductance of the uH level are required to be adopted for suppressing the high-frequency signals. In order to reduce the size of the inductor, a core inductor is usually selected, but the core inductor has poor high-frequency performance, low Q value and frequency selectivity due to the influence of the material of the core inductor itself and parasitic parameters. Simple simulation with ADS is shown in fig. 7 and 8. From the simulation result of fig. 8, it is seen that the direct current feed has a large influence on the reflection coefficient of the input port above 1GHz of the high frequency band, so that the reflection coefficient of the port is greater than-10 dB, and the performance index of the whole machine is influenced. In order to solve the above problems, in the present solution, a feeding circuit with a stepped suppression is adopted to implement power feeding, that is, an LC suppression circuit composed of one or more stages of hollow inductors and capacitors with higher high-frequency Q values and better high-frequency characteristics is added before a magnetic core power inductor according to a radio frequency signal, so as to implement the stepped suppression of the high-frequency signal, and ensure the consistency of the impedance in the whole high-frequency signal band, and the simulation result is shown in fig. 9. According to the simulation result of fig. 10, the influence of the direct current feed on the reflection coefficient of the input port above 1GHz of the high frequency band is reduced, so that the reflection coefficient of the port is smaller than-20 dB. However, the stepped feed circuit introduces an extreme point (Mark 5), so that the inductance capacitance parameter values of each stage are adjusted according to the specific use frequency of each stage in practical use, so that the reflection coefficient of each port of the use frequency band meets the requirement, and the feed stage number can be increased if necessary.

As a preferred embodiment, the respective control signals include, but are not limited to, a duplexer control signal T/R ', a low noise amplifier control signal LNA _ EN ', a power amplifier control signal PA _ EN ', and other front-end control signals, except for the above signals.

As shown in fig. 4, a system of a line-to-line rf front end control method based on OOK is composed of an rf front end unit, an rf line-to-line unit, and a baseband processing unit;

the scheduling module modulates the output radio frequency front end TTL control signals on different multi-path OOK modulators in a radio frequency one-wire-pass unit respectively to obtain modulation signals;

the modulation signal is transmitted to a front-end filter bank through a rear-end filter bank;

the front-end filter bank separates the modulation signals to obtain corresponding control signals for controlling the duplexer, the amplifier and the low-noise amplifier.

As a preferred embodiment, the carrier frequencies of the multiple OOK modulators are different, the baseband digital processing module is configured to perform information interaction with an upper layer application, and the scheduling module is further configured to control the radio frequency transceiving channel to complete information interaction with the power amplifier and the low noise amplifier.

As shown in fig. 11, the use of "OOK-based one-wire radio frequency front end control method" will be described by taking a mobile terminal supporting a remote application by skynoton number one as an example.

Adopt a ray of radio frequency cable to be connected between terminal radio frequency front end antenna and the terminal host computer, need realize: the Antenna comprises an Antenna receiving signal (2185 MHz +/-15 MHz), an Antenna transmitting signal (1995 MHz +/-15 MHz), a Beidou B1 (1561 +/-2.046 MHz), a Beidou B3 (1268.52 +/-10.23 MHz), Antenna control (2 MHz AISG: Antenna interface standards group) and a direct current power supply 30V, and meanwhile, a terminal is required to have a standby low power consumption function, so that the OOK-based one-wire radio frequency front end control method is adopted during design. The power consumption control is respectively carried out on a transmitting channel (comprising a power amplifier, a driving amplifier, a power detection circuit and the like) and a receiving channel (comprising a front-end low-noise amplifier and a gain amplifier) of a radio frequency front end, so that the optimal working power consumption is achieved.

(1) OOK carrier frequency selection

According to the principle of selecting the frequency of each signal in combination with the OOK carrier frequency, in combination with the ads (advanced Design system) software simulation, 20MHz and 40MHz are selected as the carrier frequency for controlling the transceiving channel, and the low frequency part filter circuit and the simulation result are shown in fig. 12 and 13.

(2) OOK modulation part design (terminal host end 'one line communication' radio frequency)

The OOK channel section is designed according to the frequency selection and circuit simulation results, and the high frequency section is constructed by using LTCC filters, surface acoustic wave filters (SAW), power splitters, and other devices, which are not specifically described herein.

OOK modulation local oscillators generate carrier signals by adopting 20MHz and 40MHz active crystal oscillators respectively, and OOK modulation adopts a radio frequency switch HMC849 to open and close the carrier according to a baseband control signal.

The circuit of the terminal host side 'one-wire' radio frequency part is shown in fig. 14.

(3) OOK demodulation part design (front end antenna of terminal-one line communication part)

The OOK channel portion is similar to the modulation circuit, and the high frequency portion also adopts LTCC filter, surface acoustic wave filter (SAW), power divider, etc. to construct the high frequency channel portion, which is not described herein again.

OOK demodulation adopts a power detector AD8361 with low power consumption, high dynamic and quick response to detect a carrier signal, and then a detection output signal is shaped and output through a judging comparator TLV1702 to recover a low-frequency control signal.

The circuit of the rf front end of the terminal antenna is shown in fig. 15.

(4) Results of physical tests

As can be seen from the "one-wire-pass" OOK modulation and demodulation test waveform curve (fig. 16), the delay of the radio frequency front-end control signal of the one-wire-pass based on OOK is about 1.8us, which meets the circuit design expectation, and the delay can be compensated by the baseband digital processing part, thereby meeting the design requirements of the whole machine. In addition, various radio frequency indexes (such as output power, Error Vector Magnitude (EVM), adjacent channel leakage suppression ratio (ACLR), switching time template, standby power consumption and the like) of the whole machine all meet the design requirements, so the 'OOK-based one-wire-connection radio frequency front end control method' adopted by the scheme is practical and feasible, and can be further applied to other communication systems with similar requirements.

The foregoing is merely a preferred embodiment of the invention, it is to be understood that the invention is not limited to the forms disclosed herein, but is not intended to be exhaustive or to limit the invention to other embodiments, and to various other combinations, modifications, and environments and may be modified within the scope of the inventive concept as expressed herein, by the teachings or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method for controlling a radio frequency front end of a one-wire communication based on OOK is characterized by comprising the following steps:

2. The method as claimed in claim 1, wherein the step of modulating the carrier frequency of the OOK includes:

s102: inhibiting OOK carrier frequency above 10MHz by adopting 4.7uH inductor;

3. The OOK-based front-end rf control method, according to claim 2, wherein in step S102, a feeding circuit with staged suppression is adopted to implement power feeding, that is, an LC suppression circuit comprising one or more stages of air-core inductors and capacitors is added before a magnetic core power inductor to implement staged suppression of high-frequency signals.

4. The OOK-based one-wire-through radio frequency front end control method according to claim 3, wherein the OOK carrier frequency is directly generated using a low power crystal oscillator.

5. The OOK-based one-wire-pass radio frequency front end control method according to claim 4, wherein the corresponding control signals comprise a duplexer control signal T/R ', a low noise amplifier control signal LNA _ EN ', and a power amplifier control signal PA _ EN '.

6. A system for implementing the OOK-based one-wire-through radio frequency front end control method is characterized in that the system is composed of a radio frequency front end unit, a radio frequency one-wire-through unit and a baseband processing unit;

7. The system of claim 6, wherein the multiple OOK modulators differ in carrier frequency.

8. The system of claim 7, wherein the baseband digital processing module is configured to interact with upper layer applications.

9. The system of claim 8, wherein the scheduling module is further configured to control a radio frequency transceiving channel to complete information interaction with the power amplifier and the low noise amplifier.