CN100505582C - Ultra-wideband radio-frequency transmission terminal system - Google Patents

Abstract

The invention is an ultrawideband radio frequency transmitting end system structure, comprising PLL, frequency divider, half-wave rectifier, frequency mixer and signal modulation switches, where the PLL outputs two signals at the same time, one as local oscillation input of the frequency mixer and the other one as medium frequency input after frequency-divided by the frequency divider and rectified by the half-wave rectifier; the signal modulation switches make binary phase shift keying (BPSK) modulation and are connected between the half-wave rectifier and frequency mixer, or between the PLL and frequency mixer. And it has characters of: simple structure, where 2n frequency divider and half-wave rectifier circuits are easy to implement; applicable to 3.1G-5GHz low frequency range, and 6G-10G high frequency range, even extended to higher frequency range, and high spectrum utilization ratio; low-power transmitting end; easy to make CMOS integration, where the frequency mixer, frequency divider, half-wave rectifier and PLL can all be implemented by CMOS circuits; high pulse signal controllability; and high data transmission rate.

Description

The ultra-wideband radio-frequency transmission terminal system

Technical field

The present invention relates to a kind of radio-frequency communication equipment, especially a kind of ultra-wideband radio-frequency transmission terminal system belongs to the radio-frequency communication field.

Background technology

Ultra broadband (UWB) wireless telecommunications receive great concern in recent years, especially in Wireless Personal Network (WPAN) field, comprise that Wireless USB, bluetooth of future generation all will adopt super-broadband tech; High data transmission rate (480Mbps@2m, 110Mbps@10m), low-power consumption and low cost be its maximum characteristics.It is different from traditional arrowband communication modes based on carrier wave, but a kind of based on the impulse radio of subnanosecond burst pulse or the broadband communications of multi-carrier OFDM (OFDM) technology.2002 US Federal Communication Committee (FCC) ultra broadband is defined as: fractional bandwidth is greater than 0.2 (fractional bandwidth $\mathrm{FBW}=\frac{2(f_H-f_L)}{f_H+f_L},$ F wherein _H, f _LBe with respect to maximum spectrum density-10dB Frequency point) or absolute bandwidth (10dB bandwidth) more than or equal to 500MHz; The spectral range of having stipulated ultra broadband simultaneously is 3.1G-10.6GHz, and maximum transmission power density is no more than-41.3dBm/MHz, masking spectrum as shown in Figure 1, wherein, the masking spectrum of Fig. 1 (a) expression indoor ultra-broadband system; The masking spectrum of the outdoor radio ultra wide band system of Fig. 1 (b) expression.

At present, there are two big standards (IEEE Std.802.15.3a) in U.S.'s electronics and The Institution of Electrical Engineers (IEEE) at super-broadband tech: the one, and be that the OFDM modulation technique is with in the employing of representative more with Texas Instrument (TI) and Intel (Intel) company, 3.1G-10.6GHz frequency band range is divided into 14 subbands, each subband 528MHz bandwidth, adopt the mode of frequency hopping once to take three subbands at least, thereby realize super-broadband tech.Document B.Razavi, T.Aytur, C.Lametal., " A UWB CMOS Transceiver ", IEEE J.of Solid-State Circuits, vol.40, no.12, pp.2555-2562, Dec.2005 has reported the ultra-wide band transceiver that adopts this standard, as shown in Figure 2, and in order to reach the purpose that once takies three subbands, this transceiver has used three resonance networks and three phase-locked loop circuits, has therefore increased the complexity and the power consumption of design greatly.

The 2nd, be the direct sequence super-broadband tech of the employing of representative with Freescale (Freescale) company based on pulse, be 3.1G-5GHz low-frequency range and 6G-10GHz high band with 3.1G-10.6GHz frequency band division, use arbitrary frequency band all can.Existing two kinds of ultra-wideband radio-frequency transmission terminals based on pulse:

(1) is the subnanosecond burst pulse of utilizing the direct generation of some delay units to modulate, document Y.J.Zheng, Y.Tong, C.W.Ang etal., " A CMOS Carrier-less UWB Transceiver for WPAN Applications ", ISSCC Dig.Tech.Papers, pp.116-117, Feb.2006 and H.Kim, D.Park, Y.Joo, " All-Digital Low-Power CMOS Pulse Generator ", Electron.Lett., vol.40, no.24, pp.1534-1535, Nov.2004 have reported the transmitting terminal that adopts the method.The width and the amplitude of the pulse signal that this transmitting terminal produces are uncontrollable, and therefore being difficult to strictness satisfies the frequency spectrum planning requirement;

(2) be to utilize frequency mixer that the pulse modulation that base band produces is converted to the ultra broadband frequency band range, document D.D.Wentzloff, A.P.Chandrakasan, " Gaussian Pulse Generator for SubbandedUltra-Wideband Transmitters ", IEEE Trans.Microwave Theory Tech., vol.54, issue4, part2, pp.1647-1655, Jun.2006 has reported the transmitting terminal framework that adopts this method, as shown in Figure 3.At first, in this framework in order to produce the pulse that meets the demands, need a triangular pulse generator, designing accurate triangular pulse generator itself is exactly a difficult point, and this triangular pulse generator need be adjusted three external control parameters: amplitude (A), pulse duration (PW) and side-play amount (V _Off), frequency mixer output pulse is met the demands; Secondly, the triangular pulse generator is the chip exterior element, fail to be integrated in same chip with frequency mixer, phase-locked loop, filter and power amplifier, so the triangular pulse generator has increased design cost, also influences the reliability of circuit simultaneously; At last, this framework needs a power amplifier circuit between filter and ultra-wideband antenna, thereby has increased the difficulty and the complexity of design.

Summary of the invention

1. goal of the invention

At the existing problems and shortcomings of above-mentioned ultra broadband transmitting terminal, the purpose of this invention is to provide that a kind of simple in structure, pulse signal is easy to control, is suitable for that cmos device is integrated, low-power consumption and ultra-wideband radio-frequency transmission terminal system structure cheaply.The present invention is applicable to high data transmission rate, close range wireless communication application.

2. technical scheme

According to the present invention, the system configuration of ultra-wideband radio-frequency transmission terminal comprises at least: frequency mixer, signal modulation switch, frequency divider, phase-locked loop and half-wave rectifier.By the divide ratio n of choose reasonable frequency divider and the frequency f of phase-locked loop, this transmitting terminal can be applied in 3.1G-5GHz low-frequency range, 6G-10G high band even expand to the higher frequency scope, and theory diagram is shown in Fig. 4 (a) and (b).The signal modulation switch is at frequency mixer intermediate frequency (IF) input among Fig. 4 (a), the signal modulation switch is at frequency mixer local oscillator (LO) input among Fig. 4 (b), the both is that promptly binary phase shift keying (BPSK) reaches the purpose of data-modulated by the polarity of change frequency mixer input signal; Can be according to the structure of dissimilar frequency mixers, select corresponding transmitting terminal framework (a) or (b), have identical effect, and increased the flexibility ratio of design.

Shown in Fig. 4 (a), it is the sinusoidal signal of f that phase-locked loop module produces frequency, as the input of signal modulation switch module; The difference local oscillation signal input of the two-way output of signal modulation switch module and mixer module joins.The sinusoidal signal that it is f that phase-locked loop module is exported another road frequency simultaneously, as the input of n allocator module, therefore, it is the sinusoidal signal of f/n that the output of n allocator module produces frequency; The input of this output and half-wave rectifier module joins, and the middle frequency input terminal of the output of half-wave rectifier module and mixer module joins; The input of the radio-frequency (RF) output end of mixer module and band pass filter module joins, and last, the output of band pass filter module is connected to ultra-wideband antenna.

Shown in Fig. 4 (b), it is the sinusoidal signal of f that phase-locked loop module produces frequency, as the local oscillation signal input of mixer module; The sinusoidal signal that it is f that phase-locked loop module is exported another road frequency simultaneously, as the input of n allocator module, therefore, it is the sinusoidal signal of f/n that the output of n allocator module produces frequency; The input of this output and half-wave rectifier module joins, and the input of the output of half-wave rectifier module and signal modulation switch module joins; Frequency input terminal joins in the output of signal modulation switch module and the difference of mixer module; The input of the radio-frequency (RF) output end of mixer module and band pass filter module joins, and last, the output of band pass filter module is connected to ultra-wideband antenna.

Wherein, the band pass filter module in Fig. 4 (a) and (b) is optional module, can with the output of mixer module directly and ultra-wideband antenna join, also can realize purpose of the present invention.

3. inventive principle

In radio ultra wide band system based on pulse, Gaussian pulse and each rank derived function pulse thereof are most widely used, because such pulse can be satisfied the frequency spectrum planning requirement of FCC on the one hand well, availability of frequency spectrum height on the other hand, thereby can (as: 5G frequency band WLAN, radio system 802.11a) cause interference to adjacent band.Gaussian pulse can be represented with following mathematical expression:

$p\left(t\right)=\frac{1}{\sqrt{{2\mathrm{\&pi;\&sigma;}}^2}}{e}^{-\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="C200610112896E00141.png"\; state="\{\{state\}\}">t</figure-callout>}}^2}{{2\mathrm{\&sigma;}}^2}\right)}=\frac{\sqrt{2}}{\mathrm{\&alpha;}}{e}^{-\frac{{2\mathrm{\&pi;<figure-callout\; id="2"\; label="t"\; filenames="C200610112896E00141.png"\; state="\{\{state\}\}">t</figure-callout>}}^2}{{\mathrm{\&alpha;}}^2}}$

Wherein, expression σ ²The expression mean square error; α ²=4 π σ ², be a parameter; The t express time.

Fig. 6 (a) is the time domain waveform of Gaussian pulse, and frequency spectrum is shown in Fig. 6 (b).Gaussian pulse and each rank derived function thereof have following 2 character: (1) α value is more little, and corresponding time domain pulse is narrow more, thereby the frequency spectrum of frequency domain expansion is wide more; (2) exponent number of derived function (k) is high more, and the peak value of corresponding spectral density moves to higher frequency more, can represent with following formula:

$f_{\mathrm{peak}}=\sqrt{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="C200610112896E00111.png"\; state="\{\{state\}\}">k</figure-callout>}}\frac{1}{\mathrm{\&alpha;}\sqrt{\mathrm{\&pi;}}}$

In the present invention, utilize the pulse signal of low frequency (for example 250MHz) half-wave rectifier generation and the similitude (as shown in Figure 8) of Gaussian pulse signal, design parameter to half-wave rectifier is controlled, is optimized, make its output pulse approach Gaussian pulse, make full use of the time-frequency domain advantage of Gaussian pulse.In the prior art, frequency divider and half-wave rectifier cascade generally are in order to produce accurate half-wave sine (or cosine) signal, and the waveform edge changes precipitous.And applied in the present invention half-wave rectifier is the signal that approaches Gaussian pulse in order to produce, and this also is to be different from traditional application.Be example still with the 250MHz signal, the spectral density of its half-wave output signal correspondence, basically expand to 1GHz and just decay to very low (relative peak spectral density), utilize the frequency mixer of high-frequency local oscillation (for example 4GHz or 8GHz) that this pulse signal is upconverted to 3G (4G-1G) to 5G (4G+1G) frequency range, produce and satisfy FCC frequency spectrum planning requirement and the high ultra-wideband impulse signal of the availability of frequency spectrum then.

Shown in Fig. 4 (a), the local oscillation signal polarity of difference local oscillator (LO) input that the data-modulated of pulse signal can be by frequency mixer is controlled; The signal polarity of difference intermediate frequency (IF) input that also can be by frequency mixer is controlled, shown in Fig. 4 (b).Two kinds of schemes all are to adopt binary phase shift keying (BPSK) to carry out data-modulated, as shown in Figure 5.

By above explanation, those skilled in the art will be understood that band pass filter shown in Figure 4 is an optional module, promptly can remove the requirement that this module also can satisfy ultra-wideband radio-frequency transmission terminal.Band pass filter has two effects: the one, can further carry out shaping to frequency mixer output pulse, and reduce Module Design indexs such as half-wave rectifier, frequency mixer, be easy to realize; The 2nd, can stopband outer interference signal is avoided other radio system is caused interference, reaches the purpose of coexistence (Coexistence).

4. technique effect

The invention provides a kind of system configuration of the ultra-wideband radio-frequency transmission terminal based on pulse, have following advantage: (1) system configuration is simple, and 2 ⁿ(n is a natural number) frequency divider and half-wave rectifier is easy to realize on circuit; (2) can be applied to 3.1G-5GHz low-frequency range, 6G-10G high band even expand to the higher frequency scope, and availability of frequency spectrum height; (3) low-power consumption of transmitting terminal, this is simple with system configuration, employing low consumption circuit designing technique is corresponding; (4) it is integrated to be easy to CMOS, and frequency mixer, frequency divider, half-wave rectifier and phase-locked loop all can utilize cmos circuit to realize.Frequency mixer can adopt MOS active mixer structure or the passive frequency mixer based on Kilbert (Gilbert) unit; (5) the pulse signal controllability is strong; (6) data transmission rate height.

Description of drawings

Below in conjunction with accompanying drawing, describe the present invention

Fig. 1 represents the ultra broadband masking spectrum of FCC regulation, and wherein, Fig. 1 (a) is the masking spectrum of indoor ultra-broadband system, and Fig. 1 (b) is the masking spectrum of outdoor radio ultra wide band system;

Fig. 2 represents the ultra broadband transmitting terminal structural representation of one of prior art;

Fig. 3 represents the another kind of ultra broadband transmitting terminal structural representation of prior art;

Fig. 4 (a) and (b) are represented ultra broadband transmitting terminal system configuration schematic diagram of the present invention;

Fig. 5 represents BPSK data-modulated afterpulse waveform;

Fig. 6 (a) and Fig. 6 (b) represent Gaussian pulse time-domain and frequency-domain waveform respectively;

Fig. 7 is the ultra broadband transmitting terminal system configuration schematic diagram of a preferred embodiment of the present invention;

Fig. 8 represents halfwave rectifier afterpulse waveform and Gaussian pulse relatively;

Fig. 9 (a) and Fig. 9 (b) represent frequency mixer output pulse time-domain and frequency-domain waveform respectively;

Figure 10 (a) and Figure 10 (b) represent band pass filter output pulse time-domain and frequency-domain waveform respectively.

Embodiment

Ultra-wideband radio-frequency transmission terminal system structure of the present invention has the concrete embodiment of two covers:

The one, shown in Fig. 4 (a), frequency is that the output of phase-locked loop module of f and the input of signal modulation switch module join; The difference local oscillation signal input of the two-way output of signal modulation switch module and mixer module joins.The signal that it is f that phase-locked loop module is exported another road frequency simultaneously, as the input of n allocator module, therefore, it is the sinusoidal signal of f/n that the output of n allocator module produces frequency; The input of this output and half-wave rectifier module joins, and the middle frequency input terminal of the output of half-wave rectifier module and mixer module joins; The input of the radio-frequency (RF) output end of mixer module and band pass filter module joins, and last, the output of band pass filter module is connected to ultra-wideband antenna.Wherein, the band pass filter module is optional module, can with the output of mixer module directly and ultra-wideband antenna join.

The 2nd, shown in Fig. 4 (b), frequency is that the output of phase-locked loop module of f is as the local oscillation signal input of mixer module; The sinusoidal signal that it is f that phase-locked loop module is exported another road frequency simultaneously, as the input of n allocator module, therefore, it is the sinusoidal signal of f/n that the output of n allocator module produces frequency; The input of this output and half-wave rectifier module joins, and the input of the output of half-wave rectifier module and signal modulation switch module joins; Frequency input terminal joins in the output of signal modulation switch module and the difference of mixer module; The input of the radio-frequency (RF) output end of mixer module and band pass filter module joins, and last, the output of band pass filter module is connected to ultra-wideband antenna.Wherein, the band pass filter module is optional module, can with the output of mixer module directly and ultra-wideband antenna join.

With first kind of embodiment is example, its specific implementation as shown in Figure 7, this example can be applicable to 3.1G-5GHz low-frequency range or 6G-10GHz high band, and can satisfy FCC frequency spectrum planning requirement well.

As shown in Figure 7, it is the sinusoidal signal of 8GHz that phase-locked loop module produces frequency, and this sine output signal is by 2 frequency dividers by " enable signal " control.When enable signal was high level " 1 ", output frequency was the signal of 4GHz; When enable signal is low level " 0 ", input signal is not carried out 2 frequency divisions, output still is the signal of 8GHz.Equaling " 1 " with enable signal is example, output two-way 4GHz signal, and one tunnel input as the signal modulation switch, another road is as the input of 16 frequency dividers.Therefore the output at 16 frequency dividers produces 250MHz (4GHz/16) signal, and this 250MHz signal is exported half-wave voltage signal shown in Figure 8 by half-wave rectifier; The half-wave voltage signal of 250MHz and the local oscillation signal of 4GHz process frequency mixer, the pulse signal shown in the output map 9 (a), frequency spectrum is shown in Fig. 9 (b); Pass through optional band pass filter again, the pulse signal shown in output Figure 10 (a), frequency spectrum as Figure 10 (b) shown in; At last, pulse signal is transmitted into free space by ultra-wideband antenna.By simulation result as seen, the pulse signal controllability of output is strong, can satisfy the ultra broadband FCC frequency spectrum planning requirement of 3.1G-5GHz low-frequency range well.

In like manner, when enable signal equals " 0 ", output two-way 8GHz signal, one tunnel input as the signal modulation switch, the signal of 500MHz (8GHz/16) is exported as the input of 16 frequency dividers in another road; This signal is behind half-wave rectifier, and the pulse frequency spectrum of generation expands to 2GHz, utilizes the frequency mixer of local oscillator 8GHz that this pulse is upconverted to 6G (8G-2G) to 10G (8G+2G) frequency range, produce the ultra-wideband impulse signal of high band then.

Claims (6)

1. a ultra-wideband radio-frequency transmission terminal system comprises phase-locked loop, frequency divider, half-wave rectifier, frequency mixer, signal modulation switch and 2 frequency dividers of being controlled by enable signal, wherein,

Described phase-locked loop is exported two paths of signals simultaneously, and one the tunnel as the input of the local oscillator of frequency mixer, another road through the frequency divider frequency division and by the half-wave rectifier rectification after as the intermediate frequency input of frequency mixer;

Described signal modulation switch carries out the binary phase shift keying modulation to data, inserts between half-wave rectifier and frequency mixer, perhaps inserts between phase-locked loop and frequency mixer;

Described 2 frequency dividers by enable signal control are used for output with described phase-locked loop and divide two-way output again after through the control of 2 frequency divisions.

2. ultra-wideband radio-frequency transmission terminal as claimed in claim 1 system is characterized in that also comprise band pass filter, the output that it is input as described frequency mixer is output as armed signal.

3. ultra-wideband radio-frequency transmission terminal as claimed in claim 1 or 2 system is characterized in that, described signal modulation switch adopts binary phase shift keying to carry out data-modulated.

4. ultra-wideband radio-frequency transmission terminal as claimed in claim 1 or 2 system is characterized in that described frequency divider is 2 ⁿFrequency divider, wherein, n is a natural number.

5. ultra-wideband radio-frequency transmission terminal as claimed in claim 2 system is characterized in that, also comprises ultra-wideband antenna, is used to launch the signal of described band pass filter output.

6. ultra-wideband radio-frequency transmission terminal as claimed in claim 1 system is characterized in that, also comprises ultra-wideband antenna, is used to launch the signal of described frequency mixer output.

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