CN109541648A - A kind of high-precision carrier-to-noise ratio estimation method and system - Google Patents

A kind of high-precision carrier-to-noise ratio estimation method and system Download PDF

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CN109541648A
CN109541648A CN201811459783.4A CN201811459783A CN109541648A CN 109541648 A CN109541648 A CN 109541648A CN 201811459783 A CN201811459783 A CN 201811459783A CN 109541648 A CN109541648 A CN 109541648A
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frequency conversion
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carrier
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CN109541648B (en
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踪念科
刘洋
王登峰
钟兴旺
张攀
刘玄
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Xian Institute of Space Radio Technology
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/13—Receivers
    • G01S19/23—Testing, monitoring, correcting or calibrating of receiver elements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
    • G01R29/26—Measuring noise figure; Measuring signal-to-noise ratio

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  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
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  • Computer Networks & Wireless Communication (AREA)
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Abstract

A kind of high-precision carrier-to-noise ratio estimation method, observation is obtained for plural Conversion Receiver or superhet, and the narrow band signal observation by calculating separately variety classes receiver, broadband noise observation, the power ratio of narrow band signal and broadband noise is formed, then the carrier-to-noise ratio as unit of decibel is calculated by power ratio.The present invention passes through the frequency conversion value or virtual frequency conversion value formation broadband noise observation before integral cleaning, the unfolding calculation on the basis of broadband frequency conversion value and correlation, overcome the problem of all kinds of carrier-to-noise ratio estimation method precision are difficult to further increase, cannot accurately reflect the minor fluctuations of receiver signal quality in the prior art.

Description

A kind of high-precision carrier-to-noise ratio estimation method and system
Technical field
The present invention relates to a kind of high-precision carrier-to-noise ratio estimation method and systems, belong to signal quality monitoring field.
Background technique
Carrier-to-noise ratio is the ratio of receiver received signal power and noise spectral density, is assessment receiver received signal quality Important indicator, which reflects the measurement and communication performance of receiver under present signal conditions indirectly.
By Wanfang Database to domestic open academic journal, academic dissertation, meeting paper, patent, standard, regulation etc. into Row retrieval, search condition are as follows: cql: the estimation of // carrier-to-noise ratio retrieves the relevant document of 18 conditions altogether；By to science and techniques of defence Information resources service system (DTIRSS, Defence Technology Information Resources Service System it) is retrieved, which includes IEL, Elsevier, EI, Springer, AD database, NASA database, DE Database etc., search condition are (CNR or SNR)+quadratic search (Estimation), retrieve the related text of 11 conditions altogether It offers.
Recognize that carrier-to-noise ratio estimation method is broadly divided into following a few classes from domestic and international open source literature retrieval:
(1) wide and narrow strip Power ratio method
The wide and narrow strip power ratio carrier-to-noise ratio estimation technique is that Van Dierendonck was proposed in 1996, and this method is The carrier-to-noise ratio estimation method being most widely used in the band spread receivers such as GNSS.Wide and narrow strip power ratio carrier-to-noise ratio estimation method is by one Group correlation is respectively formed narrow-band power and broadband signal power, is then passed through by coherent accumulation and non-coherent accumulation Wide, narrow band power designs look-up table, tables look-up and obtain final carrier-to-noise ratio than the relation formula between carrier-to-noise ratio.This method Typical feature is to form broadband signal and narrow band signal observation, and utilize the quantitative relationship between wide and narrow strip signal power Calculate carrier-to-noise ratio.
Typical document is as follows:
[1]B.W.Parkinson,J.J.Spilker,P.Axelrad&Per Enge.Global Positioning System:Theory and Application,Vol.I[M].American Institute of Aeronautics and Astronautics,1996:390-399.
(2) noise branching
The noise branch carrier-to-noise ratio estimation technique is in addition to wide and narrow strip Power ratio method, using most in the band spread receivers such as GNSS A kind of one of carrier-to-noise ratio estimation method.This estimation method by the way that additional noise associated branch is arranged, i.e., by with input The incoherent pseudo noise of signal is related to input signal progress, finds out equivalent noise power estimation value, binding signal branch Signal power estimated value, can be in the hope of signal-to-noise ratio, and then obtains final carrier-to-noise ratio.The typical feature of this method is, additional Increase noise associated branch, and utilizes pseudo noise formation noise power estimation value related to signal progress.
Typical document is as follows:
[1] Kaplan.GPS receiver principle
(3) Moment Methods
Moment Methods are the direct carrier-to-noise ratio estimation methods in a kind of Gaussian channel, and the basic principle of this method is to utilize correlation The second moment and Fourth-order moment of value, establish the equation group of signal power and noise power, by resolve equation, acquire signal power, The ratio of noise power or both, and finally it is converted into carrier-to-noise ratio.The typical feature of Moment Methods is, by establish not same order square with Equation between estimated value, is directly resolved, and therefore, Moment Methods also referred to as directly solve method, and some documents are also referred to as variance Summation.
Typical document is as follows:
[1]Mark L.Psiaki,Dennis M.Akos,Jonas Thor.A Comparison of”Direct RFsampling”and“Down-Convert&Sampling”GNSS Reciver Architectures[C].Proceed ION GPS/GNSS 2003,9.
[2] a kind of effective GNSS receiver carrier-to-noise ratio estimation method [J] Wuhan University Journal of Ba Xiaohui, Liu Haiyang (information science version), 2011,36 (4): 457-460.
(4) signal-to-noise ratio structured approach
Signal-to-noise ratio structured approach represents a kind of estimation method, such method passes through the correlation of in-phase branch and quadrature branch, Signal power estimator and noise power estimator are constructed, obtains signal-to-noise ratio (SNR) estimation value, and then obtain carrier-to-noise ratio estimated value.It is typical Signal-to-noise ratio building method again include SNV method, RSCN method, both methods assumes that useful signal concentrates on in-phase branch On, and noise then all exists in in-phase branch and noise branch road, such method typical feature is utilized with phase and orthogonal branch The composition feature of signal and noise in the correlation of road to construct SNR estimator, and then forms carrier-to-noise ratio.
Typical document is as follows:
[1]Pauluzzi,D.&Beaulieu,N.A Comparison of SNR Estimation Techniques for the AWGN Channel[J].Communications,IEEE Transactions on,2000,48:1681- 1691.
[2] estimation of Chen Lei indoor and outdoor seamless navigation receiver carrier-to-noise ratio inhibits the industry of the Harbin [D] with cross-correlation interference University, 2012.
(5) BL method
BL method is substantially also a kind of signal-to-noise ratio building method, and this method is proposed for QPSK modulating system, The characteristics of Beaulieu gives 4 kinds of estimators in document, this 4 kinds of estimators are based on qpsk modulation signal is believed in QPSK Number receive when, in-phase branch is identical as the signal that quadrature branch correlation is included, and it includes noise power it is identical but Independently of each other, signal power is obtained by in-phase branch and quadrature branch correlation quadratic sum, and asks poor by two-way correlation Noise observation after obtaining signal cancellation, the then ratio of available signal power and noise power, and utilize signal-to-noise ratio It is converted into carrier-to-noise ratio.This method typical feature is that QPSK signal in-phase branch is utilized with quadrature branch correlation includes phase With signal component and independent noise component(s), SNR estimator is constructed with this, and then re-form carrier-to-noise ratio, it should be pointed out that Related document difference is asked by the correlation to BPSK in-phase branch, BL method has been generalized in BPSK modulating system.
Typical document is as follows:
[1]Beaulieu,N.；Toms,A.&Pauluzzi,D.Comparison of Four SNR Estimators for QPSK Modulations.Communications Letters,IEEE,2000,4:43-45.
Above-mentioned all kinds of methods, the input quantity for carrier-to-noise ratio estimation are the correlations after correlator integral, and related Device integral has low-pass filtering effect, can reduce influence of the noise to signal power valuation, but also reduce noise function simultaneously The precision of rate valuation, therefore, above-mentioned all kinds of carrier-to-noise ratio estimation method precision are difficult to further increase, and cannot accurately reflect receiver The minor fluctuations of signal quality.
Summary of the invention
Technical problem solved by the present invention is in currently available technology, it is known that carrier-to-noise ratio estimation method precision is difficult to The problem of further increasing, while cannot accurately reflecting receiver signal quality minor fluctuations proposes a kind of high-precision load It makes an uproar rate estimation and system.
The present invention solves above-mentioned technical problem and is achieved by following technical solution:
A kind of high-precision carrier-to-noise ratio estimation method, steps are as follows:
(1) AD sampling is carried out to the output signal of plural Conversion Receiver or superhet, to AD sampled signal into Row frequency-conversion processing generates different in-phase branch frequency conversion value and quadrature branch frequency conversion value according to receiver type respectively；
(2) the in-phase branch frequency conversion value of the step (1) generation, quadrature branch frequency conversion value are subjected to integral cleaning respectively, Obtain in-phase branch correlation, quadrature branch correlation；
(3) in-phase branch correlation, quadrature branch correlation obtained by the step (2) integral is carried out respectively to add up, and To integral accumulation result it is squared and, obtain narrow-band power observation；
(4) according to in-phase branch frequency conversion value obtained by receiver type, step (1) and quadrature branch frequency conversion value, step (2) institute The in-phase branch correlation and quadrature branch correlation of identical receiver type are obtained, broadband frequency conversion observation is calculated, broadband is become It is cumulative that integral is carried out after the progress square of frequency observation again, obtains broadband noise power observation；
(5) according to broadband noise power observation obtained by narrow-band power observation, step (4) obtained by step (3), meter Calculation obtains wide and narrow strip power ratio；
(6) the wide and narrow strip power ratio obtained using the step (5), is calculated the carrier-to-noise ratio as unit of decibel.
In the step (1), when receiver type is plural Conversion Receiver, letter is sampled to orthogonal I, Q two-way AD It number carries out plural frequency conversion and generates two-way frequency conversion value, respectively in-phase branch frequency conversion value, quadrature branch frequency conversion value, calculation formula is such as Under:
In formula, ddci、ddcqRespectively in-phase branch frequency conversion value, quadrature branch frequency conversion value, It is sampled for the road I AD,It is sampled for the road Q AD, wherein PdFor sampled signal power, ωiFor sampled signal circular frequency, TsFor the sampling period, n is sampling instant, φiFor sampled signal Phase, PnTo sample noise power, ηi(n)、ηqIt (n) is respectively the moment I road n, the road Q unit sampling noise, ηi(n) and ηq(n) it is Mean value is zero and irrelevant random noise；Cos (ω in formulaonTs+φo) it is that the local cosine branch that carrier track generates is road-load Wave, sin (ωonTs+φo) it is the local sinusoidal branch carrier wave that carrier track generates, ωoFor local trace carrier wave circular frequency, φoFor local trace carrier phase；
In the step (1), when receiver type is superhet, single channel AD sampling is only carried out, which is adopted Sample signal executes real number frequency conversion, generates two-way frequency conversion value, respectively in-phase branch frequency conversion value and quadrature branch frequency conversion value, generates change Frequency value calculation formula is as follows:
In formula, ddci、ddcqRespectively in-phase branch frequency conversion value, quadrature branch frequency conversion value, It is sampled for 1 road AD, wherein PdFor sampled signal power, ωiFor sampled signal circular frequency, TsFor sampling Period, n are sampling instant, φiFor sampled signal phase, PnTo sample noise power, ηi(n) noise is sampled for n moment unit, And ηi(n) it is random noise that mean value is zero；Cos (ω in formulaonTs+φo) it is that the local cosine branch that carrier track generates is road-load Wave, sin (ωonTs+φo) it is the local sinusoidal branch carrier wave that carrier track generates, ωoFor local trace carrier wave circular frequency, φoFor local trace carrier phase.
In the step (2), by the step (1) generate in-phase branch frequency conversion value, quadrature branch frequency conversion value respectively into Row integral cleaning treatment, the integral cleaning treatment are as follows: carry out n times integral respectively and add up and obtain two-way correlation, respectively In-phase branch correlation, quadrature branch correlation, the integral cumulative time is T every times, total integral accumulation interval is NTs, The calculation formula for obtaining correlation is as follows:
In formula, corri、corrqRespectively in-phase branch correlation and quadrature branch correlation, m are m-th of correlation, often A correlation corresponds to N number of sampling instant.
In the step (3), narrow-band power observation calculation formula is as follows:
In formula, nb is narrow-band power observation, and k is k-th of observation, and each observation corresponds to M correlation, and Corresponding MN sampling instant, integrating accumulation interval every time is NTs, total integral accumulation interval is MNTs。
In the step (4), when receiver type is plural Conversion Receiver, broadband noise power observation step is calculated It is rapid as follows:
(a) the quadrature branch frequency conversion value generated in the step (1) is participated in carrying directly as broadband frequency conversion observation and is made an uproar It is used as broadband frequency conversion observation participation load to make an uproar than estimation, or after the in-phase branch frequency conversion value that the step (1) generates is sought difference Than estimation, in which:
The formula for calculating broadband frequency conversion observation using quadrature branch frequency conversion value is as follows:
ddcqo(n)=ddcq(n)
The formula for calculating broadband frequency conversion observation using in-phase branch frequency conversion value is as follows:
In formula, ddcqoIt (n) is n moment broadband frequency conversion observation, and two formulas respectively correspond width in plural Conversion Receiver Two kinds of specific implementations with frequency conversion observation；
(b) by the progress square of frequency conversion observation in broadband obtained by step (a), it is tired that MN integral then is carried out to squared results Add, obtain broadband noise power observation, the integral cumulative time is T every times, total integral accumulation interval is MNTs, wide Band noise power observation calculation formula is as follows:
In formula, wb is broadband noise power observation, and k is k-th of observation, when each observation corresponds to MN sampling It carves；
In the step (4), when receiver type is superhet, broadband noise power observation step is calculated It is as follows:
(c) the sinusoidal branch that gained in-phase branch correlation, carrier track NCO are generated in step (1) is tracked into signal phase Multiply, and multiplied by zoom factor, obtain the road the Q AD sampled signal being equivalent in plural Conversion Receiver, obtains the equivalent road Q AD sampling The calculation formula of signal is as follows:
In formula, ADqIt (n) is the n moment equivalent road Q AD sampled signal, corriIt (m) is in-phase branch correlation, sin (ωonTs+φo) it is that the sinusoidal branch that carrier wave NCO is generated tracks signal,For zoom factor；
(d) by the equivalent road the Q AD sampled signal of gained in step (c), the same phase branch for being equivalent to plural Conversion Receiver is carried out Road frequency conversion or quadrature branch frequency conversion obtain virtual in-phase branch frequency conversion value or virtual quadrature branch frequency conversion value, virtual same phase Branch frequency conversion value, the calculation formula of virtual orthographic branch frequency conversion value difference are as follows:
In formula, ddciv、ddcqvRespectively virtual in-phase branch frequency conversion value, virtual quadrature branch frequency conversion value, ADq(n) For the n moment equivalent road Q AD sampled signal, It is corresponding Frequency conversion value in superhet Frequency conversion value ddc in corresponding superhetq(n)；
(e) the virtual orthographic branch frequency conversion value for generating the step (d) participates in carrier-to-noise ratio as broadband frequency conversion observation Estimation, or it is used as frequency conversion observation in broadband to participate in carrying after the virtual in-phase branch frequency conversion value that the step (d) generates is sought difference It makes an uproar than estimation, in which:
The formula for calculating broadband frequency conversion observation using virtual orthographic branch frequency conversion value is as follows:
ddcqo(n)=ddcqv(n)
The calculation formula for calculating broadband frequency conversion observation using virtual in-phase branch frequency conversion value is as follows:
In formula, ddcqo(n) it indicates n moment broadband frequency conversion observation, and respectively corresponds the change of superhet middle width strip Two kinds of specific implementations of frequency observation；
(f) by the progress square of frequency conversion observation in broadband obtained by step (e), MN integral is carried out to squared results and is added up, Broadband noise power observation is obtained, the integral cumulative time is T every times, total integral accumulation interval MNTs, broadband is made an uproar Acoustical power observation calculation formula is as follows:
In formula, wb indicates broadband noise power observation, and k indicates that k-th of observation, each observation correspond to MN and adopt The sample moment.
In the step (5), narrow-band power observation and the step (4) that the step (3) obtains are obtained Broadband noise power observation make division, obtain wide and narrow strip power ratio, calculation formula is as follows:
In formula, nw indicates wide and narrow strip power ratio, and k corresponds to kth time observation, and each wide and narrow strip power ratio corresponds to MN sampling Moment.
In the step (6), the calculation formula for obtaining the carrier-to-noise ratio CNR as unit of decibel is as follows:
In formula, CNR indicates that the carrier-to-noise ratio as unit of decibel, corresponding k-th of the observation of k, each observation correspond to MN Sampling instant, i.e., every MN sampling generate a carrier-to-noise ratio estimated result.
A kind of high-precision carrier-to-noise ratio estimating system, including external receiver module, carrier tracking module, carrier-to-noise ratio estimate mould Block, in which:
External receiver module: carrying out AD data sampling, when receiver type is plural Conversion Receiver, by sampling It obtains orthogonal I, Q two-way AD sampled signal and is sent into carrier tracking module；When receiver type is superhet, will sample Gained single channel AD sampled signal is sent into carrier tracking module；
Carrier tracking module: it receives the AD sampled signal that external receiver module is sent and carries out frequency-conversion processing, according to reception Machine type generates different in-phase branch frequency conversion value and quadrature branch frequency conversion value respectively, and carries out integral cleaning, and integral is cleaned Gained in-phase branch correlation, quadrature branch correlation are sent to carrier-to-noise ratio estimation module afterwards；
Carrier-to-noise ratio estimation module: in-phase branch correlation, the quadrature branch correlation point that carrier tracking module is sent are received It is cumulative not carry out integral, and to integral accumulation result it is squared and, obtain narrow-band power observation；Simultaneously according to receiver Type, the in-phase branch frequency conversion value of identical receiver type and quadrature branch frequency conversion value, the in-phase branch of identical receiver type Correlation and quadrature branch correlation value calculation broadband noise power observation；According to narrow-band power observation, broadband noise Power observation calculates wide and narrow strip power ratio and wide and narrow strip power ratio.
The advantages of the present invention over the prior art are that:
(1) a kind of high-precision carrier-to-noise ratio estimation method provided by the invention is seen based on correlation and frequency conversion value as basic Measured value, wherein correlation is used to power estimator signal, and frequency conversion value is then used to estimating noise power, and all methods known are basic Observation is only with correlation；Relative to previous methods, since frequency conversion value has broader noise bandwidth, as noise Observation is influenced to be reduced by signal power fluctuation, therefore obtained noise power is more accurate, is made an uproar using broadband Sound observation and narrow band signal observation Combined estimator, so that carrier-to-noise ratio estimation method proposed by the present invention, has more accurate Carrier-to-noise ratio estimated accuracy；
(2) by using plural conversion architecture or the virtual plural number constructed using correlation and tracking carrier wave in the present invention Conversion architecture, eliminate in frequency conversion value and frequency signal component so that either plural conversion architecture receiver still In super-heterodyne structural receiver, the observation of noise power can be constructed based on frequency conversion value, structure is simple, is convenient for work Cheng Shixian.
Detailed description of the invention
Fig. 1 is the plural Conversion Receiver quadrature branch carrier-to-noise ratio estimation schematic diagram that invention provides；
Fig. 2 is the plural Conversion Receiver in-phase branch carrier-to-noise ratio estimation schematic diagram that invention provides；
Fig. 3 is the superhet virtual orthographic branch carrier-to-noise ratio estimation schematic diagram that invention provides；
Fig. 4 is the virtual in-phase branch carrier-to-noise ratio estimation schematic diagram of superhet that invention provides；
Fig. 5 is each carrier-to-noise ratio estimation method precision simulation comparison diagram of plural Conversion Receiver that invention provides；
Fig. 6 is each carrier-to-noise ratio estimation method precision simulation comparison diagram of superhet that invention provides；
Specific embodiment
A kind of high-precision carrier-to-noise ratio estimation method and system, are seen for plural Conversion Receiver or superhet The calculating of measured value, while by obtaining frequency conversion value and virtual frequency conversion value, form narrow-band power observation and broadband noise function Rate observation, then find out the power ratio of narrow band signal and broadband noise and be converted to the carrier-to-noise ratio as unit of decibel, specifically Steps are as follows:
(1) frequency conversion is executed to the AD sampled signal of incoming carrier tracking module according to receiver type, generates two-way and becomes Frequency is worth, respectively in-phase branch frequency conversion value, quadrature branch frequency conversion value.
In the step (1), when receiver type is plural Conversion Receiver, there is orthogonal I, Q two-way AD sampling letter Number incoming carrier tracking module executes plural frequency conversion, generates two-way frequency conversion value, respectively in-phase branch frequency conversion value, quadrature branch It is as follows to generate frequency conversion value calculation formula for frequency conversion value:
Ddc in formulai、ddcqIn-phase branch frequency conversion value, quadrature branch frequency conversion value are respectively indicated,Item indicates the road I AD sampling, Item indicates the road Q AD sampling, wherein PdIndicate sampled signal power, ωiIndicate sampled signal circular frequency, TsTable Show the sampling period, n indicates sampling instant, φiIndicate sampled signal phase, PnIndicate sampling noise power, ηi(n)、ηq(n) divide Not Biao Shi the moment I road n, the road Q unit sample noise, and ηi(n) and ηqIt (n) be mean value is zero and irrelevant random noise；Formula Middle cos (ωonTs+φo) item indicate carrier tracking module tracking generate local cosine branch carrier wave, sin (ωonTs+φo) item Indicate the local sinusoidal branch carrier wave that carrier tracking module tracking generates, wherein ωoIndicate local trace carrier wave circular frequency, φoIndicate local trace carrier phase.
In the step (1), when receiver type is superhet, only 1 road AD sampled signal incoming carrier Tracking module executes real number frequency conversion, generates two-way frequency conversion value, respectively in-phase branch frequency conversion value and quadrature branch frequency conversion value, produces The frequency value calculation formula that changes is as follows:
In formulaItem 1 road AD of table is sampled, wherein PdIndicate sampled signal Power, ωiIndicate sampled signal circular frequency, TsIndicate the sampling period, n indicates sampling instant, φiIndicate sampled signal phase, PnIndicate sampling noise power, ηi(n) indicate that n moment unit samples noise, and ηi(n) it is random noise that mean value is zero；In formula cos(ωonTs+φo) item indicate carrier tracking module tracking generate local cosine branch carrier wave, sin (ωonTs+φo) item table Show the local sinusoidal branch carrier wave that carrier tracking module tracking generates, wherein ωoIndicate local trace carrier wave circular frequency, φo Indicate local trace carrier phase；Ddc in formulai、ddcqRespectively indicate in-phase branch frequency conversion value, quadrature branch frequency conversion value.
(2) the in-phase branch frequency conversion value of the step (1) generation, quadrature branch frequency conversion value n times integral is carried out respectively to tire out Add, generate two-way correlation, respectively in-phase branch correlation, quadrature branch correlation, the integral cumulative time is T every times, Total integral accumulation interval is NTs, it is as follows to generate correlation value calculation formula:
In formula, corri、corrqIn-phase branch correlation and quadrature branch correlation are respectively indicated, m indicates m-th of correlation Value, each correlation correspond to N number of sampling instant.
(3) in-phase branch correlation, the quadrature branch correlation generated the step (2) is sent into carrier-to-noise ratio and estimates mould Block, it is cumulative to carry out M integral respectively, and to integral accumulation result it is squared and, generation narrow-band power observation all the way, often Secondary integral accumulation interval is NTs, total integral accumulation interval is MNTs, generate narrow-band power observation and calculate public affairs Formula is as follows:
In formula, nb indicates narrow-band power observation, and k indicates that k-th of observation, each observation correspond to M correlation Value, and corresponding MN sampling instant.
(4) according to receiver type, the frequency conversion value generated using the step (1) is in conjunction with generation in the step (2) In-phase branch correlation generates broadband frequency conversion observation, then progress square carries out integral to squared results and adds up, obtains to broadband and make an uproar Acoustical power observation；
In the step (4), when receiver type is plural Conversion Receiver, broadband noise is generated using following steps Power observation:
(a) the quadrature branch frequency conversion value for generating the step (1) participates in carrier-to-noise ratio directly as broadband frequency conversion observation Estimation, or it is used as broadband frequency conversion observation participation load to make an uproar after the in-phase branch frequency conversion value that the step (1) generates is sought difference Than estimation；
The formula that the step (a) directly generates broadband frequency conversion observation is as follows:
ddcqo(n)=ddcq(n)
The step (a) is as follows using the calculation formula that difference generates broadband frequency conversion observation:
In above-mentioned two formula, ddcqo(n) n moment broadband frequency conversion observation is indicated, and two formulas respectively correspond plural frequency conversion and connect Two kinds of specific implementations of receipts machine middle width strip frequency conversion observation.
(b) the broadband frequency conversion observation of the step (a) will be come from, then progress square carries out MN to squared results Secondary integral is cumulative, obtains broadband noise power observation, and the integral cumulative time is T every times, total integral accumulation interval is M·N·Ts, broadband noise power observation calculation formula is as follows:
In formula, wb indicates broadband noise power observation, and k indicates that k-th of observation, each observation correspond to MN and adopt The sample moment.
In the step (4), when receiver type is superhet, broadband noise function is generated using following steps Rate observation:
(c) the in-phase branch correlation that will be generated in the step (1) is generated with carrier wave NCO in carrier tracking module Sinusoidal branch tracks signal multiplication, and multiplied by zoom factor, obtains the road the Q AD being equivalent in plural Conversion Receiver sampling letter Number, the calculation formula for generating the equivalent road Q AD sampled signal is as follows:
In formula, ADq(n) the n moment equivalent road Q AD sampled signal is indicated, corri (m) is in-phase branch correlation, sin (ω OnTs+ φ o) it is that the sinusoidal branch that carrier wave NCO is generated tracks signal,For zoom factor.
(d) the equivalent road the Q AD sampled signal that will be generated in the step (c), carries out being equivalent to plural Conversion Receiver In-phase branch frequency conversion or quadrature branch frequency conversion, it is corresponding to generate virtual in-phase branch frequency conversion value or virtual quadrature branch frequency conversion Value；It is as follows to generate virtual in-phase branch frequency conversion value, the calculation formula of quadrature branch frequency conversion value difference:
Ddc in formulaiv、ddcqvRespectively indicate virtual in-phase branch frequency conversion value, virtual quadrature branch frequency conversion value, ADq(n) Indicate the n moment equivalent road Q AD sampled signal, Item is right Answer the frequency conversion value ddc in superheti(n), and Frequency conversion value ddc in the corresponding superhet of itemq(n).By in-phase branch frequency conversion value virtual in superhet, orthogonal Branch frequency conversion value calculation formula is compared with the frequency conversion value calculation formula in plural Conversion Receiver, it can be seen that super outer The equivalent road the Q AD sampled signal of step (c) construction has been used in poor reception machine, and has carried out virtual plural frequency conversion, because This, is defined as virtual frequency conversion value for the frequency conversion value that the step (d) generates.
(e) the virtual orthographic branch frequency conversion value for generating the step (d) participates in carrying directly as broadband frequency conversion observation It makes an uproar than estimation, or is used as broadband frequency conversion observation after the virtual in-phase branch frequency conversion value that the step (d) generates is sought difference Participate in carrier-to-noise ratio estimation；
The formula that the step (e) directly generates broadband frequency conversion observation is as follows:
ddcqo(n)=ddcqv(n)
The step (e) is as follows using the calculation formula that calculus of finite differences generates broadband frequency conversion observation:
In above-mentioned two formula, ddcqo(n) it indicates n moment broadband frequency conversion observation, and respectively corresponds in superhet Two kinds of specific implementations of broadband frequency conversion observation.
(f) the broadband frequency conversion observation of the step (e) will be come from, then progress square carries out MN to squared results Secondary integral is cumulative, obtains broadband noise power observation, and the integral cumulative time is T every times, total integral accumulation interval M N·Ts, it is as follows to generate broadband noise power observation calculation formula:
In formula, wb indicates broadband noise power observation, and k indicates that k-th of observation, each observation correspond to MN and adopt The sample moment.
(5) by the narrow-band power observation that the step (3) obtains and the broadband noise function that the step (4) obtain Rate observation makees division, obtains wide and narrow strip power ratio, and calculation formula is as follows:
In formula, nw indicates that wide and narrow strip power ratio, corresponding k-th of the wide and narrow strip power ratio of k, each wide and narrow strip power ratio correspond to MN sampling instant.
(6) the wide and narrow strip power ratio obtained using the step (5), is calculated as unit of decibel according to the following equation Carrier-to-noise ratio CNR, calculation formula is as follows:
In formula, CNR indicates that the carrier-to-noise ratio as unit of decibel, corresponding k-th of the carrier-to-noise ratio of k, each carrier-to-noise ratio correspond to MN A sampling instant, i.e., every MN AD sampled signal can produce a carrier-to-noise ratio estimated result.
It mainly include external receiver module, carrier tracking module, load meanwhile in high-precision carrier-to-noise ratio estimating system It makes an uproar compared estimate module, in which:
External receiver module: carrying out AD data sampling, when receiver type is plural Conversion Receiver, by sampling It obtains orthogonal I, Q two-way AD sampled signal and is sent into carrier tracking module；When receiver type is superhet, will sample Gained single channel AD sampled signal is sent into carrier tracking module；
Carrier tracking module: it receives the AD sampled signal that external receiver module is sent and carries out frequency-conversion processing, according to reception Machine type generates different in-phase branch frequency conversion value and quadrature branch frequency conversion value respectively, and carries out integral cleaning, and integral is cleaned Gained in-phase branch correlation, quadrature branch correlation are sent to carrier-to-noise ratio estimation module afterwards；
Carrier-to-noise ratio estimation module: in-phase branch correlation, the quadrature branch correlation point that carrier tracking module is sent are received It is cumulative not carry out integral, and to integral accumulation result it is squared and, obtain narrow-band power observation；Simultaneously according to receiver Type, the in-phase branch frequency conversion value of identical receiver type and quadrature branch frequency conversion value, the in-phase branch of identical receiver type Correlation and quadrature branch correlation value calculation broadband noise power observation；According to narrow-band power observation, broadband noise Power observation calculates wide and narrow strip power ratio and wide and narrow strip power ratio.
Below according to receiver type and broadband noise observation, it is further described in conjunction with specific embodiments:
Embodiment 1
Plural Conversion Receiver as shown in Figure 1, carrier-to-noise ratio estimate that implementation steps are as follows:
(1) there is orthogonal I, Q two-way AD sampled signal incoming carrier tracking module, execute plural frequency conversion, generate two-way and become Frequency is worth, respectively in-phase branch frequency conversion value, quadrature branch frequency conversion value, and it is as follows to generate frequency conversion value calculation formula:
Ddc in formulai、ddcqIn-phase branch frequency conversion value, quadrature branch frequency conversion value are respectively indicated,Item indicates the road I AD sampling, Item indicates the road Q AD sampling, wherein PdIndicate sampled signal power, ωiIndicate sampled signal circular frequency, TsTable Show the sampling period, n indicates sampling instant, φiIndicate sampled signal phase, PnIndicate sampling noise power, ηi(n)、ηq(n) divide Not Biao Shi the moment I road n, the road Q unit sample noise, and ηi(n) and ηqIt (n) be mean value is zero and irrelevant random noise；Formula Middle cos (ωonTs+φo) item indicate carrier tracking module tracking generate local cosine branch carrier wave, sin (ωonTs+φo) item Indicate the local sinusoidal branch carrier wave that carrier tracking module tracking generates, wherein ωoIndicate local trace carrier wave circular frequency, φoIndicate local trace carrier phase.
(2) the in-phase branch frequency conversion value of the step (1) generation, quadrature branch frequency conversion value are respectively fed to integral cleaning mould Block carries out n times integral respectively and adds up, generates two-way correlation, respectively in-phase branch correlation, quadrature branch correlation, often The secondary integral cumulative time is Ts, total integral accumulation interval is NTs, it is as follows to generate correlation value calculation formula:
In formula, corri、corrqIn-phase branch correlation and quadrature branch correlation are respectively indicated, m indicates m-th of correlation Value, each correlation correspond to N number of sampling instant.
(3) in-phase branch correlation, the quadrature branch correlation generated the step (2) is sent into carrier-to-noise ratio and estimates mould Block, it is cumulative to carry out M integral respectively, and to integral accumulation result it is squared and, generation narrow-band power observation all the way, often Secondary integral accumulation interval is NTs, total integral accumulation interval is MNTs, generate narrow-band power observation and calculate public affairs Formula is as follows:
In formula, nb indicates narrow-band power observation, and k indicates that k-th of observation, each observation correspond to M correlation Value, and corresponding MN sampling instant.
(4) broadband noise power observation is generated using following steps:
(a) the quadrature branch frequency conversion value for generating the step (1) participates in carrier-to-noise ratio directly as broadband frequency conversion observation Estimation, the formula that the step (a) directly generates broadband frequency conversion observation are as follows:
ddcqo(n)=ddcq(n)
In formula, ddcqo(n) n moment broadband frequency conversion observation is indicated.
(b) the broadband frequency conversion observation of the step (a) will be come from, then progress square carries out MN to squared results Secondary integral is cumulative, obtains broadband noise power observation, and the integral cumulative time is T every times, total integral accumulation interval is M·N·Ts, broadband noise power observation calculation formula is as follows:
In formula, wb indicates broadband noise power observation, and k indicates that k-th of observation, each observation correspond to MN and adopt The sample moment.
(5) by the narrow-band power observation that the step (3) obtains and the broadband noise function that the step (4) obtain Rate observation makees division, obtains wide and narrow strip power ratio, and calculation formula is as follows:
In formula, nw indicates that wide and narrow strip power ratio, corresponding k-th of the wide and narrow strip power ratio of k, each wide and narrow strip power ratio correspond to MN sampling instant.
(6) the wide and narrow strip power ratio obtained using the step (5), is calculated as unit of decibel according to the following equation Carrier-to-noise ratio CNR, calculation formula is as follows:
In formula, CNR indicates that the carrier-to-noise ratio as unit of decibel, corresponding k-th of the carrier-to-noise ratio of k, each carrier-to-noise ratio correspond to MN A sampling instant, i.e., every MN AD sampled signal can produce a carrier-to-noise ratio estimated result.
Embodiment 2
Plural Conversion Receiver as shown in Figure 2, carrier-to-noise ratio estimate that implementation steps are as follows:
(1) there is orthogonal I, Q two-way AD sampled signal incoming carrier tracking module, execute plural frequency conversion, generate two-way and become Frequency is worth, respectively in-phase branch frequency conversion value, quadrature branch frequency conversion value, and it is as follows to generate frequency conversion value calculation formula:
Ddc in formulai、ddcqIn-phase branch frequency conversion value, quadrature branch frequency conversion value are respectively indicated,Item indicates the road I AD sampling, Item indicates the road Q AD sampling, wherein PdIndicate sampled signal power, ωiIndicate sampled signal circular frequency, TsTable Show the sampling period, n indicates sampling instant, φiIndicate sampled signal phase, PnIndicate sampling noise power, ηi(n)、ηq(n) divide Not Biao Shi the moment I road n, the road Q unit sample noise, and ηi(n) and ηqIt (n) be mean value is zero and irrelevant random noise；Formula Middle cos (ωonTs+φo) item indicate carrier tracking module tracking generate local cosine branch carrier wave, sin (ωonTs+φo) item Indicate the local sinusoidal branch carrier wave that carrier tracking module tracking generates, wherein ωoIndicate local trace carrier wave circular frequency, φoIndicate local trace carrier phase.
(2) the in-phase branch frequency conversion value of the step (1) generation, quadrature branch frequency conversion value are respectively fed to integral cleaning mould Block carries out n times integral respectively and adds up, generates two-way correlation, respectively in-phase branch correlation, quadrature branch correlation, often The secondary integral cumulative time is Ts, total integral accumulation interval is NTs, it is as follows to generate correlation value calculation formula:
In formula, corri、corrqIn-phase branch correlation and quadrature branch correlation are respectively indicated, m indicates m-th of correlation Value, each correlation correspond to N number of sampling instant.
(3) in-phase branch correlation, the quadrature branch correlation generated the step (2) is sent into carrier-to-noise ratio and estimates mould Block, it is cumulative to carry out M integral respectively, and to integral accumulation result it is squared and, generation narrow-band power observation all the way, often Secondary integral accumulation interval is NTs, total integral accumulation interval is MNTs, generate narrow-band power observation and calculate public affairs Formula is as follows:
In formula, nb indicates narrow-band power observation, and k indicates that k-th of observation, each observation correspond to M correlation Value, and corresponding MN sampling instant.
(4) broadband noise power observation is generated using following steps:
(a) it is used as frequency conversion observation in broadband to participate in carrying after the in-phase branch frequency conversion value that the step (1) generates being sought difference It makes an uproar than estimation, the calculation formula for generating broadband frequency conversion observation using difference is as follows:
In formula, ddcqo(n) n moment broadband frequency conversion observation is indicated.
(b) the broadband frequency conversion observation of the step (a) will be come from, then progress square carries out MN to squared results Secondary integral is cumulative, obtains broadband noise power observation, and the integral cumulative time is T every times, total integral accumulation interval is M·N·Ts, broadband noise power observation calculation formula is as follows:
In formula, wb indicates broadband noise power observation, and k indicates that k-th of observation, each observation correspond to MN and adopt The sample moment.
(5) by the narrow-band power observation that the step (3) obtains and the broadband noise function that the step (4) obtain Rate observation makees division, obtains wide and narrow strip power ratio, and calculation formula is as follows:
In formula, nw indicates that wide and narrow strip power ratio, corresponding k-th of the wide and narrow strip power ratio of k, each wide and narrow strip power ratio correspond to MN sampling instant.
(6) the wide and narrow strip power ratio obtained using the step (5), is calculated as unit of decibel according to the following equation Carrier-to-noise ratio CNR, calculation formula is as follows:
In formula, CNR indicates that the carrier-to-noise ratio as unit of decibel, corresponding k-th of the carrier-to-noise ratio of k, each carrier-to-noise ratio correspond to MN A sampling instant, i.e., every MN AD sampled signal can produce a carrier-to-noise ratio estimated result.
Embodiment 3
Superhet as shown in Figure 3, carrier-to-noise ratio estimate that implementation steps are as follows:
(1) there is 1 road AD sampled signal incoming carrier tracking module, execute real number frequency conversion, generate two-way frequency conversion value, respectively It is as follows to generate frequency conversion value calculation formula for in-phase branch frequency conversion value and quadrature branch frequency conversion value:
In formulaItem indicates 1 road AD sampling, wherein PdIndicate sampling letter Number power, ωiIndicate sampled signal circular frequency, TsIndicate the sampling period, n indicates sampling instant, φiIndicate sampled signal phase Position, PnIndicate sampling noise power, ηi(n) indicate that n moment unit samples noise, and ηi(n) it is random noise that mean value is zero； Cos (ω in formulaonTs+φo(item indicates the local cosine branch carrier wave that carrier tracking module tracking generates, sin (ωonTs+φo) Item indicates the local sine branch carrier wave that carrier tracking module tracking generates, wherein ωoIndicate local trace carrier wave circumference frequency Rate, φoIndicate local trace carrier phase；Ddc in formulai、ddcqRespectively indicate in-phase branch frequency conversion value, quadrature branch frequency conversion value.
(2) the in-phase branch frequency conversion value of the step (1) generation, quadrature branch frequency conversion value are respectively fed to integral cleaning mould Block carries out n times integral respectively and adds up, generates two-way correlation, respectively in-phase branch correlation, quadrature branch correlation, often The secondary integral cumulative time is Ts, total integral accumulation interval is NTs, it is as follows to generate correlation value calculation formula:
In formula, corri、corrqIn-phase branch correlation and quadrature branch correlation are respectively indicated, m indicates m-th of correlation Value, each correlation correspond to N number of sampling instant.
(3) in-phase branch correlation, the quadrature branch correlation generated the step (2) is sent into carrier-to-noise ratio and estimates mould Block, it is cumulative to carry out M integral respectively, and to integral accumulation result it is squared and, generation narrow-band power observation all the way, often Secondary integral accumulation interval is NTs, total integral accumulation interval is MNTs, generate narrow-band power observation and calculate public affairs Formula is as follows:
In formula, nb indicates narrow-band power observation, and k indicates that k-th of observation, each observation correspond to M correlation Value, and corresponding MN sampling instant.
(4) broadband noise power observation is generated using following steps:
(c) the in-phase branch correlation that will be generated in the step (1) is generated with carrier wave NCO in carrier tracking module Sinusoidal branch tracks signal multiplication, and multiplied by zoom factor, obtains the road the Q AD being equivalent in plural Conversion Receiver sampling letter Number, the calculation formula for generating the equivalent road Q AD sampled signal is as follows:
In formula, ADq(n) the n moment equivalent road Q AD sampled signal, corr are indicatediIt (m) is in-phase branch correlation, sin (ωonTs+φo) item be carrier wave NCO generate sinusoidal branch track signal,For zoom factor.
(d) the equivalent road the Q AD sampled signal that will be generated in the step (c), carries out being equivalent to plural Conversion Receiver In-phase branch frequency conversion or quadrature branch frequency conversion, it is corresponding to generate virtual in-phase branch frequency conversion value or virtual quadrature branch frequency conversion Value；It is as follows to generate virtual in-phase branch frequency conversion value, the calculation formula of quadrature branch frequency conversion value difference:
Ddc in formulaiv、ddcqvRespectively indicate virtual in-phase branch frequency conversion value, virtual quadrature branch frequency conversion value, ADq(n) Indicate the n moment equivalent road Q AD sampled signal, Item is right Answer the frequency conversion value ddc in superheti(n), and Frequency conversion value ddc in the corresponding superhet of itemq(n).By in-phase branch frequency conversion value virtual in superhet, orthogonal Branch frequency conversion value calculation formula is compared with the frequency conversion value calculation formula in plural Conversion Receiver, it can be seen that super outer The equivalent road the Q AD sampled signal of step (c) construction has been used in poor reception machine, and has carried out virtual plural frequency conversion, because This, is defined as virtual frequency conversion value for the frequency conversion value that the step (d) generates.
(e) the virtual orthographic branch frequency conversion value for generating the step (d) participates in carrying directly as broadband frequency conversion observation It makes an uproar than estimation, the formula of directly generation broadband frequency conversion observation is as follows:
ddcqo(n)=ddcqv(n)
In formula, ddcqo(n) n moment broadband frequency conversion observation is indicated.
(f) the broadband frequency conversion observation of the step (e) will be come from, then progress square carries out MN to squared results Secondary integral is cumulative, obtains broadband noise power observation, and the integral cumulative time is T every times, total integral accumulation interval M N·Ts, it is as follows to generate broadband noise power observation calculation formula:
In formula, wb indicates broadband noise power observation, and k indicates that k-th of observation, each observation correspond to MN and adopt The sample moment.
(5) by the narrow-band power observation that the step (3) obtains and the broadband noise function that the step (4) obtain Rate observation makees division, obtains wide and narrow strip power ratio, and calculation formula is as follows:
In formula, nw indicates that wide and narrow strip power ratio, corresponding k-th of the wide and narrow strip power ratio of k, each wide and narrow strip power ratio correspond to MN sampling instant.
(6) the wide and narrow strip power ratio obtained using the step (5), is calculated as unit of decibel according to the following equation Carrier-to-noise ratio CNR, calculation formula is as follows:
In formula, CNR indicates that the carrier-to-noise ratio as unit of decibel, corresponding k-th of the carrier-to-noise ratio of k, each carrier-to-noise ratio correspond to MN A sampling instant, i.e., every MN AD sampled signal can produce a carrier-to-noise ratio estimated result.
Embodiment 4
Superhet as shown in Figure 4, carrier-to-noise ratio estimate that implementation steps are as follows:
(1) there is 1 road AD sampled signal incoming carrier tracking module, execute real number frequency conversion, generate two-way frequency conversion value, respectively It is as follows to generate frequency conversion value calculation formula for in-phase branch frequency conversion value and quadrature branch frequency conversion value:
In formulaItem 1 road AD of table is sampled, wherein PdIndicate sampled signal Power, ωiIndicate sampled signal circular frequency, TsIndicate the sampling period, n indicates sampling instant, φiIndicate sampled signal phase, PnIndicate sampling noise power, ηi(n) indicate that n moment unit samples noise, and ηi(n) it is random noise that mean value is zero；In formula cos(ωonTs+φo) item indicate carrier tracking module tracking generate local cosine branch carrier wave, sin (ωonTs+φo) item table Show the local sinusoidal branch carrier wave that carrier tracking module tracking generates, wherein ωoIndicate local trace carrier wave circular frequency, φo Indicate local trace carrier phase；Ddc in formulai、ddcqRespectively indicate in-phase branch frequency conversion value, quadrature branch frequency conversion value.
(2) the in-phase branch frequency conversion value of the step (1) generation, quadrature branch frequency conversion value are respectively fed to integral cleaning mould Block carries out n times integral respectively and adds up, generates two-way correlation, respectively in-phase branch correlation, quadrature branch correlation, often The secondary integral cumulative time is Ts, total integral accumulation interval is NTs, it is as follows to generate correlation value calculation formula:
In formula, corri、corrqIn-phase branch correlation and quadrature branch correlation are respectively indicated, m indicates m-th of correlation Value, each correlation correspond to N number of sampling instant.
(3) in-phase branch correlation, the quadrature branch correlation generated the step (2) is sent into carrier-to-noise ratio and estimates mould Block, it is cumulative to carry out M integral respectively, and to integral accumulation result it is squared and, generation narrow-band power observation all the way, often Secondary integral accumulation interval is NTs, total integral accumulation interval is MNTs, generate narrow-band power observation and calculate public affairs Formula is as follows:
In formula, nb indicates narrow-band power observation, and k indicates that k-th of observation, each observation correspond to M correlation Value, and corresponding MN sampling instant.
(4) broadband noise power observation is generated using following steps:
(c) the in-phase branch correlation that will be generated in the step (1) is generated with carrier wave NCO in carrier tracking module Sinusoidal branch tracks signal multiplication, and multiplied by zoom factor, obtains the road the Q AD being equivalent in plural Conversion Receiver sampling letter Number, the calculation formula for generating the equivalent road Q AD sampled signal is as follows:
In formula, ADq(n) the n moment equivalent road Q AD sampled signal, corr are indicatediIt (m) is in-phase branch correlation, sin (ωonTs+φo) it is that the sinusoidal branch that carrier wave NCO is generated tracks signal,For zoom factor.
(d) the equivalent road the Q AD sampled signal that will be generated in the step (c), carries out being equivalent to plural Conversion Receiver In-phase branch frequency conversion or quadrature branch frequency conversion, it is corresponding to generate virtual in-phase branch frequency conversion value or virtual quadrature branch frequency conversion Value；It is as follows to generate virtual in-phase branch frequency conversion value, the calculation formula of quadrature branch frequency conversion value difference:
Ddc in formulaiv、ddcqvRespectively indicate virtual in-phase branch frequency conversion value, virtual quadrature branch frequency conversion value, ADq(n) Indicate the n moment equivalent road Q AD sampled signal, Item is right Answer the frequency conversion value ddc in superheti(n), and Frequency conversion value ddc in the corresponding superhet of itemq(n).By in-phase branch frequency conversion value virtual in superhet, orthogonal Branch frequency conversion value calculation formula is compared with the frequency conversion value calculation formula in plural Conversion Receiver, it can be seen that super outer The equivalent road the Q AD sampled signal of step (c) construction has been used in poor reception machine, and has carried out virtual plural frequency conversion, because This, is defined as virtual frequency conversion value for the frequency conversion value that the step (d) generates.
(e) it is used as frequency conversion observation in broadband to join after the virtual in-phase branch frequency conversion value that the step (d) generates being sought difference It is estimated with carrier-to-noise ratio, the calculation formula for generating broadband frequency conversion observation using calculus of finite differences is as follows:
In formula, ddcqo(n) n moment broadband frequency conversion observation is indicated.
(f) the broadband frequency conversion observation of the step (e) will be come from, then progress square carries out MN to squared results Secondary integral is cumulative, obtains broadband noise power observation, and the integral cumulative time is T every times, total integral accumulation interval M N·Ts, it is as follows to generate broadband noise power observation calculation formula:
In formula, wb indicates broadband noise power observation, and k indicates that k-th of observation, each observation correspond to MN and adopt The sample moment.
(5) by the narrow-band power observation that the step (3) obtains and the broadband noise function that the step (4) obtain Rate observation makees division, obtains wide and narrow strip power ratio, and calculation formula is as follows:
In formula, nw indicates that wide and narrow strip power ratio, corresponding k-th of the wide and narrow strip power ratio of k, each wide and narrow strip power ratio correspond to MN sampling instant.
(6) the wide and narrow strip power ratio obtained using the step (5), is calculated as unit of decibel according to the following equation Carrier-to-noise ratio CNR, calculation formula is as follows:
In formula, CNR indicates that the carrier-to-noise ratio as unit of decibel, corresponding k-th of the carrier-to-noise ratio of k, each carrier-to-noise ratio correspond to MN A sampling instant, i.e., every MN AD sampled signal can produce a carrier-to-noise ratio estimated result.
In examples detailed above, example 1, example 2 are directed to plural Conversion Receiver, and wherein example 1 uses quadrature branch frequency conversion value Carrier-to-noise ratio estimation is participated in as broadband frequency conversion observation, example 2 asks difference to see as broadband frequency conversion using in-phase branch frequency conversion value Measured value participates in carrier-to-noise ratio estimation.To wide and narrow strip method (NW), noise branching (NP), moments estimation method in plural Conversion Receiver (MM), signal-to-noise ratio construction SNV method, signal-to-noise ratio construction RSCN method, the typical carrier-to-noise ratio estimation method such as BL method and example 1, Example 2 is emulated, and when emulation every time for forming 1 correlation is NTs=1ms, every 1 carrier-to-noise ratio estimated value of formation A length of MNT when samplings=100ms, carrier-to-noise ratio true value range is from 30dBHz~100dBHz, it is contemplated that actual carrier tracking When, due to the influence of phase noise, there can be a non-ideal tracking characteristics, when emulation introduces typical carrier phase jitter about 2.5 °, carrier-to-noise ratio estimated accuracy is counted, statistical formula uses: Example 1,2 simulation result of example are as shown in Figure 5.
By Fig. 5 it can be seen that present example 1 is in receiver typical case's carrier-to-noise ratio range 30dBHz~85dBHz, have than Other higher estimated accuracies of carrier-to-noise ratio estimation method；When being greater than 85dBHz, the estimated accuracy of present example 1 is estimated close to square Meter method and BL method；When being greater than the high carrier-to-noise ratio of 90dBHz, estimated accuracy is lower than moment estimation method and BL method, and exhausted Most of receivers will not work in this high carrier-to-noise ratio condition.Present example 2 due to use differential broadband frequency conversion observation, It is insensitive to phase noise, therefore, essence more higher than other typical case's carrier-to-noise ratio estimation methods is all had in 30dBHz~100dBHz Degree.
In examples detailed above, example 3, example 4 are directed to superhet, and wherein example 3 uses the frequency conversion of virtual orthographic branch Value participates in carrier-to-noise ratio estimation as broadband frequency conversion observation, and example 4 asks difference as broadband using virtual in-phase branch frequency conversion value Frequency conversion observation participates in carrier-to-noise ratio estimation, using with example 1,2 identical simulated conditions and statistical method, example 3, example 4 are imitative True result is as shown in Figure 6.
By Fig. 6 it can be seen that present example 3 is in receiver typical case's carrier-to-noise ratio range 30dBHz~85dBHz, have than Other higher estimated accuracies of carrier-to-noise ratio estimation method；When being greater than 85dBHz, the estimated accuracy of present example 1 is estimated close to square Meter method and BL method；When being greater than the high carrier-to-noise ratio of 90dBHz, estimated accuracy is lower than moment estimation method and BL method, and exhausted Most of receivers will not work in this high carrier-to-noise ratio.Present example 4 is due to using differential broadband frequency conversion observation, to phase Position noise sensitivity decreases, and opposite example 3 is with higher precision, but relatively plural 2 precision of Conversion Receiver example Declined, there is precision more higher than other typical case's carrier-to-noise ratio estimation methods in 30dBHz~90dBHz, when greater than 90dBHz High carrier-to-noise ratio when, estimated accuracy is close to moment estimation method and BL method.
In conclusion being emulated according to correlation, it can be seen that carrier-to-noise ratio estimation method proposed by the present invention, receiver typical case carry It makes an uproar than in range 30dBHz~85dBHz, there is estimated accuracy more higher than other carrier-to-noise ratio estimation methods, it can be more accurate Reflection receiver signal quality minor fluctuations, in addition, can see according to implementation process, either in plural conversion architecture For receiver still in super-heterodyne structural receiver, implementation structure is all fairly simple, is convenient for Project Realization.

Claims (8)

1. a kind of high-precision carrier-to-noise ratio estimation method, it is characterised in that steps are as follows:
(1) AD sampling is carried out to the output signal of plural Conversion Receiver or superhet, AD sampled signal is become Frequency is handled, and generates different in-phase branch frequency conversion value and quadrature branch frequency conversion value respectively according to receiver type；
(2) the in-phase branch frequency conversion value of the step (1) generation, quadrature branch frequency conversion value are subjected to integral cleaning respectively, obtained In-phase branch correlation, quadrature branch correlation；
(3) in-phase branch correlation, quadrature branch correlation obtained by the step (2) are carried out integral respectively to add up, and to product Divide accumulation result squared and obtains narrow-band power observation；
(4) according to phase obtained by in-phase branch frequency conversion value obtained by receiver type, step (1) and quadrature branch frequency conversion value, step (2) With the in-phase branch correlation and quadrature branch correlation of receiver type, broadband frequency conversion observation is calculated, broadband frequency conversion is seen It is cumulative that integral is carried out after measured value progress square again, obtains broadband noise power observation；
(5) it according to broadband noise power observation obtained by narrow-band power observation, step (4) obtained by step (3), calculates To wide and narrow strip power ratio；
(6) the wide and narrow strip power ratio obtained using the step (5), is calculated the carrier-to-noise ratio as unit of decibel.
2. a kind of high-precision carrier-to-noise ratio estimation method according to claim 1, it is characterised in that:
In the step (1), when receiver type is plural Conversion Receiver, to orthogonal I, Q two-way AD sampled signal into Row plural number frequency conversion simultaneously generates two-way frequency conversion value, and respectively in-phase branch frequency conversion value, quadrature branch frequency conversion value, calculation formula are as follows:
In formula, ddci、ddcqRespectively in-phase branch frequency conversion value, quadrature branch frequency conversion value, It is sampled for the road I AD,It is sampled for the road Q AD, wherein PdFor sampled signal power, ωiFor sampled signal circular frequency, TsFor the sampling period, n is sampling instant, φiFor sampled signal Phase, PnTo sample noise power, ηi(n)、ηqIt (n) is respectively the moment I road n, the road Q unit sampling noise, ηi(n) and ηq(n) it is Mean value is zero and irrelevant random noise；Cos (ω in formulaonTs+φo) it is that the local cosine branch that carrier track generates is road-load Wave, sin (ωonTs+φo) it is the local sinusoidal branch carrier wave that carrier track generates, ωoFor local trace carrier wave circular frequency, φoFor local trace carrier phase；
In the step (1), when receiver type is superhet, single channel AD sampling is only carried out, which is sampled and is believed Number real number frequency conversion is executed, generates two-way frequency conversion value, respectively in-phase branch frequency conversion value and quadrature branch frequency conversion value generate frequency conversion value Calculation formula is as follows:
In formula, ddci、ddcqRespectively in-phase branch frequency conversion value, quadrature branch frequency conversion value, It is sampled for 1 road AD, wherein PdFor sampled signal power, ωiFor sampled signal circular frequency, TsFor sampling Period, n are sampling instant, φiFor sampled signal phase, PnTo sample noise power, ηi(n) noise is sampled for n moment unit, And ηi(n) it is random noise that mean value is zero；Cos (ω in formulaonTs+φo) it is that the local cosine branch that carrier track generates is road-load Wave, sin (ωonTs+φo) it is the local sinusoidal branch carrier wave that carrier track generates, ωoFor local trace carrier wave circular frequency, φoFor local trace carrier phase.
3. a kind of high-precision carrier-to-noise ratio estimation method according to claim 2, it is characterised in that:
In the step (2), the in-phase branch frequency conversion value of the step (1) generation, quadrature branch frequency conversion value are accumulated respectively Divide cleaning treatment, the integral cleaning treatment are as follows: n times integral is carried out respectively to add up and obtain two-way correlation, respectively same phase Branch correlation, quadrature branch correlation, the integral cumulative time is T every times, total integral accumulation interval is NTs, obtain The calculation formula of correlation is as follows:
In formula, corri、corrqRespectively in-phase branch correlation and quadrature branch correlation, m are m-th of correlation, Mei Gexiang Pass value corresponds to N number of sampling instant.
4. according to a kind of high-precision carrier-to-noise ratio estimation method any in claim 3, it is characterised in that:
In the step (3), narrow-band power observation calculation formula is as follows:
In formula, nb is narrow-band power observation, and k is k-th of observation, and each observation corresponds to M correlation, and corresponding MN sampling instant, integrating accumulation interval every time is NTs, total integral accumulation interval is MNTs。
5. a kind of high-precision carrier-to-noise ratio estimation method according to claim 4, it is characterised in that:
In the step (4), when receiver type is plural Conversion Receiver, broadband noise power observation step is calculated such as Under:
(a) the quadrature branch frequency conversion value generated in the step (1) carrier-to-noise ratio is participated in directly as broadband frequency conversion observation to estimate It calculates, or is used as broadband frequency conversion observation participation carrier-to-noise ratio to estimate after the in-phase branch frequency conversion value that the step (1) generates is sought difference It calculates, in which:
The formula for calculating broadband frequency conversion observation using quadrature branch frequency conversion value is as follows:
ddcqo(n)=ddcq(n)
The formula for calculating broadband frequency conversion observation using in-phase branch frequency conversion value is as follows:
In formula, ddcqoIt (n) is n moment broadband frequency conversion observation, and two formulas respectively correspond plural Conversion Receiver middle width strip and become Two kinds of specific implementations of frequency observation；
(b) by the progress square of frequency conversion observation in broadband obtained by step (a), MN integral then is carried out to squared results and is added up, Broadband noise power observation is obtained, the integral cumulative time is T every times, total integral accumulation interval is MNTs, broadband Noise power observation calculation formula is as follows:
In formula, wb is broadband noise power observation, and k is k-th of observation, and each observation corresponds to MN sampling instant；
In the step (4), when receiver type is superhet, broadband noise power observation step is calculated such as Under:
(c) the sinusoidal branch that gained in-phase branch correlation, carrier track NCO are generated in step (1) is tracked into signal multiplication, and Multiplied by zoom factor, the road the Q AD sampled signal being equivalent in plural Conversion Receiver is obtained, obtains the equivalent road Q AD sampled signal Calculation formula it is as follows:
In formula, ADqIt (n) is the n moment equivalent road Q AD sampled signal, corriIt (m) is in-phase branch correlation, sin (ωonTs+ φo) it is that the sinusoidal branch that carrier wave NCO is generated tracks signal,For zoom factor；
(d) by the equivalent road the Q AD sampled signal of gained in step (c), the in-phase branch for be equivalent to plural Conversion Receiver becomes Frequency or quadrature branch frequency conversion, obtain virtual in-phase branch frequency conversion value or virtual quadrature branch frequency conversion value, virtual in-phase branch Frequency conversion value, the calculation formula of virtual orthographic branch frequency conversion value difference are as follows:
In formula, ddciv、ddcqvRespectively virtual in-phase branch frequency conversion value, virtual quadrature branch frequency conversion value, ADq(n) be n when The equivalent road Q AD sampled signal is carved, It is corresponding Frequency conversion value ddc in superheti(n), Frequency conversion value ddc in corresponding superhetq(n)；
(e) the virtual orthographic branch frequency conversion value for generating the step (d) participates in carrier-to-noise ratio estimation as broadband frequency conversion observation, Or the virtual in-phase branch frequency conversion value that the step (d) generates is asked and participates in carrier-to-noise ratio as broadband frequency conversion observation after difference and estimates It calculates, in which:
The formula for calculating broadband frequency conversion observation using virtual orthographic branch frequency conversion value is as follows:
ddcqo(n)=ddcqv(n)
The calculation formula for calculating broadband frequency conversion observation using virtual in-phase branch frequency conversion value is as follows:
In formula, ddcqo(n) it indicates n moment broadband frequency conversion observation, and respectively corresponds superhet middle width strip frequency conversion sight Two kinds of specific implementations of measured value；
(f) by the progress square of frequency conversion observation in broadband obtained by step (e), MN integral is carried out to squared results and is added up, is obtained Broadband noise power observation, the integral cumulative time is T every times, total integral accumulation interval MNTs, broadband noise function Rate observation calculation formula is as follows:
In formula, wb indicates broadband noise power observation, and k indicates k-th of observation, when each observation corresponds to MN sampling It carves.
6. a kind of high-precision carrier-to-noise ratio estimation method according to claim 5, it is characterised in that:
In the step (5), by the narrow-band power observation that the step (3) obtains and the width that the step (4) obtain Band noise power observation makees division, obtains wide and narrow strip power ratio, calculation formula is as follows:
In formula, nw indicates wide and narrow strip power ratio, and k corresponds to kth time observation, when each wide and narrow strip power ratio corresponds to MN sampling It carves.
7. a kind of high-precision carrier-to-noise ratio estimation method according to claim 6, it is characterised in that:
In the step (6), the calculation formula for obtaining the carrier-to-noise ratio CNR as unit of decibel is as follows:
In formula, CNR indicates that the carrier-to-noise ratio as unit of decibel, corresponding k-th of the observation of k, each observation correspond to MN sampling Moment, i.e., every MN sampling generate a carrier-to-noise ratio estimated result.
8. a kind of high-precision carrier-to-noise ratio estimating system, it is characterised in that: including external receiver module, carrier tracking module, load It makes an uproar compared estimate module, in which:
External receiver module: carrying out AD data sampling, when receiver type is plural Conversion Receiver, just by sampling gained I, Q two-way AD sampled signal of friendship are sent into carrier tracking module；When receiver type is superhet, by sampling gained Single channel AD sampled signal is sent into carrier tracking module；
Carrier tracking module: it receives the AD sampled signal that external receiver module is sent and carries out frequency-conversion processing, according to receiver class Type generates different in-phase branch frequency conversion value and quadrature branch frequency conversion value respectively, and carries out integral cleaning, by institute after integral cleaning Obtain in-phase branch correlation, quadrature branch correlation is sent to carrier-to-noise ratio estimation module；
Carrier-to-noise ratio estimation module: receive carrier tracking module send in-phase branch correlation, quadrature branch correlation respectively into Row integral is cumulative, and to integral accumulation result it is squared and, obtain narrow-band power observation；Simultaneously according to receiver class Type, the in-phase branch frequency conversion value of identical receiver type and quadrature branch frequency conversion value, the in-phase branch phase of identical receiver type Pass value and quadrature branch correlation value calculation broadband noise power observation；According to narrow-band power observation, broadband noise function Rate observation calculates wide and narrow strip power ratio and wide and narrow strip power ratio.
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