The implementation method and the device of low complex degree ultra-wide band radio-frequency front end
Technical field
The present invention is a kind of ultra-wide band radio-frequency front end implementation method that is applied to the high-speed radio short haul connection, belongs to communication technical field.
Background technology
In recent years, owing to the active demand of market to the high-speed radio short haul connection, super-broadband tech (UWB) was subjected to people and more and more paid close attention to.Utilization is from the UWB frequency spectrum of 3.1GHz~10.6GHz, and telecom equipment manufacturers and operator just can make up and develop wireless personal local area network (WPAN) energetically, realizes low-power consumption, high speed wireless data access cheaply.In general, the transmission of UWB communication system data needs to surpass 100Mbps, and its communication bandwidth will reach more than the 500MHz, and these are restricted to high-speed radio UWB design of communication system and bring a little challenge.This wherein all inevitably runs into the difficult problem of wide bandwidth, two-forty such as radio circuit (low noise amplifier, frequency mixer, quadrature modulator and quadrature demodulator etc.), simulation baseband circuit (channel selection filter and variable gain amplifier etc.), digital analog converter (DAC) and analog-digital converter designs such as (ADC).These circuit must be supported the bandwidth of 500MHz at least, even possibility one tunnel up expands 7 to, 500MHz.The bandwidth that these circuit are supported is big more, and its design is just difficult more.
Summary of the invention
Technical problem: the implementation method and the device that the purpose of this invention is to provide a kind of low complex degree ultra-wide band radio-frequency front end, by between the complexity of radio frequency, simulation and mixed signal circuit, making suitable choice, reduce the design difficulty of quadrature (IQ) modulator, quadrature demodulator, high-speed a/d and high-speed d/a, thereby provide a brand-new technology route for the design of broadband wireless radio-frequency front-end.Simultaneously, this method also provides the guarantee of flexibility and reliability for the realization of whole UWB communication system.
Technical scheme: the invention provides a kind of implementation method and device succinct, low complex degree ultra-wide band radio-frequency front end reliably.As shown in Figure 1, the implementation method of low complex degree ultra-wide band radio-frequency front end is finished by multichannel input sender and multichannel output receiver,
1) at the sender end, finish the road of closing of multichannel Wideband Intermediate Frequency input signal by multiplexer, to close intermediate-freuqncy signal behind the road then and upconvert to radio frequency and get on to carry out the multicarrier emission, thereby under the situation of the system of assurance emitting performance, reduce the design difficulty of base band digital to analog converter and sender.Sender is made up of k road matched filtering circuit, k road IQ modulator, multiplexer, upconverter, radio frequency band filter, radio frequency amplifier, wide-band amplifier and transmitting antenna.From k road Simulation with I, the Q signal of baseband circuit, total I
1, Q
1, I
2, Q
2... I
k, Q
kThe road signal enters sender, through producing the intermediate-freuqncy signal of k road different center frequency behind the k road quadrature modulator in the sender, k road intermediate-freuqncy signal generates a multicarrier intermediate-freuqncy signal that has k equiband and centre frequency to have nothing in common with each other by multiplexer then, this multicarrier intermediate-freuqncy signal through upconverter be transformed to the multicarrier radiofrequency signal, again behind radio frequency band filter and radio frequency amplifier, go out by transmission antennas transmit.Automatic electric-level control (ALC) in the sender partly realizes at every road intermediate-frequency circuit.
2) at the receiver end, received signal is at first done down-converted, finish the shunt of multichannel Wideband Intermediate Frequency input signal then by multiplexer, thereby under the situation of the system of assurance receptivity, reduced receiver and the analog-to-digital design difficulty of base band.Receiver is by reception antenna, radio frequency band filter, low noise amplifier, low-converter, multiplexer, k road IQ demodulator and k road matched filtering circuit are formed, receive the multicarrier radiofrequency signal of coming from antenna, at first enter radio frequency band filter filtering, behind low noise amplifier and low-converter, generate the multicarrier intermediate-freuqncy signal that has k equiband and centre frequency to have nothing in common with each other then, this multicarrier intermediate-freuqncy signal has produced the intermediate-freuqncy signal of k road different center frequency and has entered corresponding k IQ demodulator respectively and k matched filtering circuit separated the mediation matched filter processing behind multiplexer, k road Simulation with I after the processing, Q signal, i.e. I
1, Q
1, I
2, Q
2... I
k, Q
kThe road signal is sent to base band subsequently.Automatic gain control (AGC) in the receiver partly realizes at every road intermediate-frequency circuit.
Implement device based on low complex degree ultra-wide band radio-frequency front end implementation method comprises sender and receiver two parts, wherein, and in sender: I
1Matched filtering circuit, Q
1The output termination first via IQ modulator of matched filtering circuit, output termination first alc circuit of first via IQ modulator, the output termination duplexer of first alc circuit, I
2Matched filtering circuit, Q
2Output termination the second road IQ modulator of matched filtering circuit, output termination second alc circuit of the second road IQ modulator, the output termination duplexer of second alc circuit, duplexer, upconverter, radio frequency band filter, radio frequency amplifier and transmitting antenna are connected in series in proper order; In receiver: reception antenna, radio frequency band filter, low noise amplifier, image-reject filter, low-converter, duplexer are connected in series in proper order, the output of receiver duplexer connects the input of first agc circuit, second agc circuit respectively, the input of the output termination first via IQ demodulator of first agc circuit, the output of first via IQ demodulator meets I respectively
1Matched filtering circuit, Q
1The input of matched filtering circuit; The input of output termination the second road IQ demodulator of second agc circuit, the output of the second road IQ demodulator meets I respectively
2Matched filtering circuit, Q
2The input of matched filtering circuit.
Beneficial effect: the low complex degree ultra-wide band radio-frequency Front-end Design scheme that the present invention proposes, under the situation that transmits the same frequency spectrum bandwidth, the bandwidth of the required modulator and demodulator in the multichannel scheme only is 1/k a times of traditional single channel scheme, modulator and demodulator design and debugging have been simplified in processing greatly like this, they are operated within the more satisfactory bandwidth range, thereby have preferable performance.
Under the situation that transmits equivalent data rates, required A/D in the multichannel scheme and the operating frequency of D/A only are 1/k times of traditional single channel scheme, A/D and D/A design and debugging have been simplified in processing greatly like this, reduced the cost of system, they are operated on the more satisfactory signal sampling clock, thereby have preferable performance.
Owing on each road emission medium-frequency and reception intermediate frequency, all introduced ALC or AGC, so just made system more flexible when doing transmitting power control and receiving gain control, thereby make the higher performance of the easier acquisition of system.
Description of drawings
Fig. 1 is a low complex degree ultra-wide band radio-frequency front end block diagram.Wherein have: k road matched filtering circuit, k road IQ modulator, multiplexer, upconverter, radio frequency band filter, radio frequency amplifier, wide-band amplifier, transmitting antenna, reception antenna, radio frequency band filter, low noise amplifier, low-converter, multiplexer, k road IQ demodulator, k road matched filtering circuit.
Fig. 2 is a kind of embodiment of the present invention, two carrier signaling machine system block diagrams.Wherein have: I
1Matched filtering circuit 1, Q
1Matched filtering circuit 2, I
2Matched filtering circuit 3, Q
2Matched filtering circuit 4, first via IQ modulator 5, the second road IQ modulator 6, first alc circuit 7, second alc circuit 8, duplexer 9, upconverter 10, radio frequency band filter 11, radio frequency amplifier 12, transmitting antenna 13.
Fig. 3 is a kind of embodiment of the present invention, two carrier wave receiver system block diagrams.Wherein have: reception antenna 14, radio frequency band filter 15, low noise amplifier 16, image-reject filter 17, low-converter 18, duplexer 19, first agc circuit 20, second agc circuit 21, first via IQ demodulator 22, the second road IQ demodulator 23, I
1Matched filtering circuit 24, Q
1Matched filtering circuit 25, I
2Matched filtering circuit 26, Q
2Matched filtering circuit 27.
Embodiment
The present invention has realized the experimental provision of low complex degree ultra-wide band radio-frequency front end on the 3.5GHz frequency range.This radio-frequency front-end has adopted two carrierband modulation schemes, the closing the road and finished by duplexer along separate routes of intermediate-freuqncy signal.The centre frequency of intermediate-freuqncy signal is respectively 1.188GHz and 1.452GHz, and the centre frequency of radiofrequency signal is 3.48GHz.The front end signal communication bandwidth is about 400MHz, and wherein the bandwidth of two subcarriers and the isolation bandwidth between the subcarrier are 132MHz.The transmitting power of sender is about-12dBm.
This device comprises sender and receiver two parts, wherein, and in sender: I
1Matched filtering circuit 1, Q
1The output termination first via IQ modulator 5 of matched filtering circuit 2, the output termination duplexer 9 of output termination first alc circuit 7, the first alc circuits 7 of first via IQ modulator 5, I
2Matched filtering circuit 3, Q
2Output termination the second road IQ modulator 6 of matched filtering circuit 4, output termination second alc circuit 8 of the second road IQ modulator 6, the output termination duplexer 9 of second alc circuit 8, duplexer 9, upconverter 10, radio frequency band filter 11, radio frequency amplifier 12 and transmitting antenna 13 orders are connected in series; In receiver: reception antenna 14, radio frequency band filter 15, low noise amplifier 16, image-reject filter 17, low-converter 18, duplexer 19 orders are connected in series, the output termination of duplexer 19 connects the input of first agc circuit 20, second agc circuit 21 respectively, the input of the output termination first via IQ demodulator 22 of first agc circuit 20, the output of first via IQ demodulator 22 meets I respectively
1Matched filtering circuit 24, Q
1The input of matched filtering circuit 25; The input of output termination the second road IQ demodulator 23 of second agc circuit 21, the output of the second road IQ demodulator 23 meets I respectively
2Matched filtering circuit 26, Q
2The input of matched filtering circuit 27.
Sender embodiment of the present invention as shown in Figure 2.From the first via Simulation with I of base band, Q signal (I
1And Q
1) enter I respectively
1Matched filtering circuit 1 and Q
1Matched filtering circuit 2 produces first via emission medium-frequency modulation signal by first via IQ modulator 5 and first alc circuit, 7 backs; While is from the second tunnel Simulation with I of base band, Q signal (I
2And Q
2) enter I respectively
2Matched filtering circuit 3 and Q
2Matched filtering circuit 4 produces the second road emission medium-frequency modulation signal by the second road IQ modulator 6 and first alc circuit, 8 backs; This two-way emission medium-frequency modulation signal closes road and filtering in duplexer 9, produce the two carrier wave intermediate-freuqncy signals of sender, this pair carrier wave intermediate-freuqncy signal enters upconverter 10, radio frequency band filter 11, radio frequency amplifier 12 and transmitting antenna 13 in proper order two carrier wave RF signals is transmitted in the air subsequently.
Receiver embodiment of the present invention as shown in Figure 3.Two carrier wave RF received signals produce the two carrier wave intermediate-freuqncy signals of receiver by reception antenna 14, radio frequency band filter 15, low noise amplifier 16, image-reject filter 17 and low-converter 18 backs successively; By duplexer 19 this pair carrier wave intermediate-freuqncy signal is carried out shunt and filtering, generate the first via receiving intermediate frequency signal and the second road receiving intermediate frequency signal; First via receiving intermediate frequency signal is by first agc circuit 20, first via IQ demodulator 22, I
1Matched filtering circuit 24 and Q
1Matched filtering circuit 25 backs produce I
1And Q
1Signal exports baseband circuit to; In like manner, the second road receiving intermediate frequency signal is by second agc circuit 21, the second road IQ demodulator 23, I
2Matched filtering circuit 26 and Q
2Matched filtering circuit 27 backs produce I
2And Q
2Signal exports baseband circuit to; This two-way IQ signal need be sent to baseband circuit simultaneously and handle.