CN103346848A - Method and device of noise detection - Google Patents

Abstract

The invention provides a method and device of noise detection, and relates to the field of communication, and the method and device aim to accurately detect signal noise. The method includes the steps that a noise detection device obtains a power value of sub-carriers in an OFDM symbol to be detected, an identification of a sub-carrier set corresponding to the sub-carriers is determined, a corresponding noise detection threshold value is obtained according to the identification of the sub-carrier set, when the power value of the sub-carriers meets a noise detection strategy according to the noise detection threshold value, noise exists in the sub-carriers is determined. The method and device are applied to noise detection.

Description

A kind of method and apparatus of noise measuring

Technical field

The present invention relates to the communications field, relate in particular to a kind of method and apparatus of noise measuring.

Background technology

At PLC (Power Line Communication, power line communication) in the system, it is more common interference that narrow-band noise is disturbed, in order to guarantee the normal transmission of signal, need elimination or reduce noise to the interference of signal, and before eliminating or reducing the interference of noise to signal, need detection signal whether to have noise.

In the prior art, mainly be with the performance number of subcarrier and OFDM to be detected (the Orthogonal Frequency Division Multiplexing by calculating, OFDM) ratio of the average power content of whole subcarriers of symbol correspondence and predetermined threshold value compare, if determine this ratio more than or equal to predetermined threshold value, determine that then there is noise in this subcarrier.But, noise measuring for signal in the deep fade channel on frequency domain, existing noise detection technique is too simple, the average power content and the actual subcarriers performance number error that adopt existing noise detection technique to calculate are bigger, cause false retrieval and omission to noise easily, thereby influence the transmission of signal.

Summary of the invention

Embodiments of the invention provide a kind of method and apparatus of noise measuring, to realize the accurate detection to signal noise.

For achieving the above object, embodiments of the invention adopt following technical scheme:

First aspect provides a kind of method of noise measuring, comprising:

Noise measuring equipment obtains the performance number of the subcarrier in the orthogonal frequency division multiplex OFDM symbol to be detected;

Determine the sign of the subcarrier set of described subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of described subcarrier set; Wherein, described sub-carrier set is combined into the set of determining according to default number of elements the subcarrier of described noise measuring equipment in described OFDM symbol to be detected;

When determining that according to described noise measuring threshold value the performance number of described subcarrier satisfies the noise measuring strategy, determine that there is noise in described subcarrier.

In first kind of possible implementation of first aspect, before the sign that the subcarrier of described definite described subcarrier correspondence is gathered, described method also comprises:

Determine described subcarrier set according to default number of elements the subcarrier in described OFDM symbol to be detected.

In conjunction with first aspect or first kind of possible implementation of first aspect, in second kind of possible implementation, the performance number that described noise measuring equipment obtains the subcarrier in the OFDM symbol to be detected comprises:

Determine sample OFDM symbol from the OFDM symbol that receives, wherein, described sample OFDM symbol is for being used for obtaining the determined sample symbol of performance number of subcarrier in the described OFDM symbol to be detected;

Pass through formula according to described sample OFDM symbol:

$P\left(n\right)=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{\left|r_{m,n}\right|}^2$

Obtain the performance number of the subcarrier in the described OFDM symbol to be detected; Wherein, P (n) is the performance number of the subcarrier in the described OFDM symbol to be detected, and M is the quantity of described sample OFDM symbol, and m is the sign of described sample OFDM symbol, and n is the sign of described subcarrier, r _{M, n}Be n subcarrier in m the sample OFDM symbol.

In conjunction with second kind of possible implementation, in the third possible implementation, the described sign of determining the subcarrier set of described subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of described subcarrier set and comprise:

In the subcarrier set of the sign correspondence by the set of described subcarrier all the ratio of the quantity of the interior subcarrier of the performance number sum of subcarriers and the set of described subcarrier obtain first average power content, wherein, described first average power content is the average power content of subcarrier in the described subcarrier set;

In described subcarrier set, determine maximum power value the performance number of subcarrier;

Obtain detection threshold value according to described first average power content and described maximum power value.

In conjunction with the third possible implementation, in the 4th kind of possible implementation, describedly obtain the noise measuring threshold value according to described first average power content and described maximum power value and comprise:

Obtain first detection threshold value according to described first average power content: wherein, described first detection threshold value is: AP _a(d-1)

Obtain second detection threshold value according to described first average power content: wherein, described second detection threshold value is: AP _a(d+1)

Obtain the 3rd detection threshold value according to described first average power content: wherein, described the 3rd detection threshold value is: AP _a(d)

Obtain the 4th detection threshold value according to described maximum power value: wherein, described the 4th detection threshold value is:

Wherein, d is the sign of described subcarrier set, P _a(d) be described first average power content, P _a(d+1) be the average power content of subcarrier in d+1 the sub-carrier set, P _a(d-1) be the average power content of subcarrier in d-1 the sub-carrier set, P _m(d) be maximum power value in the performance number of subcarrier in the set of described subcarrier, A is first parameter preset, and B is second parameter preset.

In conjunction with the 4th kind of possible implementation, in the 5th kind of possible implementation, described before there is noise in definite described subcarrier, described method also comprises:

Pass through formula:

Determine the quantity of described subcarrier set the subcarrier in described OFDM symbol to be detected according to default number of elements, wherein, W is the quantity of described subcarrier set, and N is the quantity of the subcarrier in the described OFDM symbol to be detected, and NS is described default number of elements;

Pass through formula:

$P_t=\frac{1}{W}\underset{d=0}{\overset{W-1}{\mathrm{\Σ}}}{P}_a\left(d\right)$

Obtain second average power content; Wherein, described P _tBe described second average power, P _a(d) be described first average power content, d is the sign of described subcarrier set, W is the quantity of described subcarrier set, and described second average power content is the average power content according to all the average power content of subcarrier obtains in the subcarriers set in the described OFDM symbol to be detected;

Described when determining that according to described noise measuring threshold value the performance number of described subcarrier satisfies the noise measuring strategy, determine that described subcarrier exists noise to comprise:

During more than or equal to described first detection threshold value, the design variables value is added 1 in the performance number of determining described subcarrier, wherein, the initial value of described design variables value is 0;

During more than or equal to described second detection threshold value, described design variables value is added 1 in the performance number of determining described subcarrier;

During more than or equal to described the 3rd detection threshold value and more than or equal to described the 4th detection threshold value, described design variables value is added 1 in the performance number of determining described subcarrier;

Greater than 1 and described second average power content during more than or equal to default power threshold, determine that there is noise in described subcarrier in definite described design variables value.

In conjunction with the 5th kind of possible implementation, in the 6th kind of possible implementation, less than described the 3rd detection threshold value, and/or the performance number of determining described subcarrier is during less than described the 4th detection threshold value, with the zero clearing of described design variables value in the performance number of determining described subcarrier.

In conjunction with the 5th kind of possible implementation or the 6th kind of possible implementation, in the 7th kind of possible implementation, after there was noise in definite described subcarrier, described method also comprised:

Whether performance number that continue to determine next subcarrier in the described OFDM symbol to be detected satisfies the noise measuring strategy; Wherein, described next subcarrier comprises the subcarrier that the sign of described subcarrier is added the sign correspondence that obtains after;

When the performance number of determining the subcarrier of default value does not continuously satisfy the noise measuring strategy, determine the noise measuring result, wherein, described noise measuring result comprises the subcarrier corresponding identification that satisfies the noise measuring strategy.

Second aspect provides a kind of noise measuring equipment, comprising:

Acquiring unit is for the performance number of obtaining the subcarrier in the orthogonal frequency division multiplex OFDM symbol to be detected;

Processing unit, the sign that is used for the subcarrier set of definite described subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of described subcarrier set, and when determining that according to described noise measuring threshold value the performance number of the subcarrier that described acquiring unit obtains satisfies the noise measuring strategy, determine that there is noise in described subcarrier; Wherein, described sub-carrier set is combined into the set of determining according to default number of elements the subcarrier of described noise measuring equipment in described OFDM symbol to be detected.

In first kind of possible implementation of second aspect, described processing unit also is used for, before the sign of the described subcarrier set of determining described subcarrier correspondence, determine described subcarrier set according to default number of elements the subcarrier in described OFDM symbol to be detected.

In conjunction with second aspect or first kind of possible implementation, in second kind of possible implementation, described acquiring unit specifically is used for, from the OFDM symbol that receives, determine sample OFDM symbol, wherein, described sample OFDM symbol is for be used for obtaining the determined sample symbol of performance number of subcarrier in the described OFDM symbol to be detected;

Pass through formula according to described sample OFDM symbol:

$P\left(n\right)=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{\left|r_{m,n}\right|}^2$

Obtain the performance number of the subcarrier in the described OFDM symbol to be detected; Wherein, P (n) is the performance number of the subcarrier in the described OFDM symbol to be detected, and M is the quantity of described sample OFDM symbol, and m is the sign of described sample OFDM symbol, and n is the sign of described subcarrier, r _{M, n}Be n subcarrier in m the sample OFDM symbol.

In conjunction with second kind of possible implementation, in the third possible implementation, described processing unit specifically is used for, in the subcarrier set of the sign correspondence by the set of described subcarrier all the ratio of the quantity of the interior subcarrier of the performance number sum of subcarriers and the set of described subcarrier obtain first average power content, in described subcarrier set, determine maximum power value the performance number of subcarrier, and obtain detection threshold value according to described first average power content and described maximum power value, wherein, described first average power content is the average power content of subcarrier in the described subcarrier set.

In conjunction with the third possible implementation, in the 4th kind of possible implementation, described processing unit specifically is used for, and obtains first detection threshold value according to described first average power content: wherein, described first detection threshold value is: AP _a(d-1)

Obtain second detection threshold value according to described first average power content: wherein, described second detection threshold value is: AP _a(d+1)

Obtain the 3rd detection threshold value according to described first average power content: wherein, described the 3rd detection threshold value is: AP _a(d)

Obtain the 4th detection threshold value according to described maximum power value: wherein, described the 4th detection threshold value is:

Wherein, d is the sign of described subcarrier set, P _a(d) be described first average power content, P _a(d+1) be the average power content of subcarrier in d+1 the sub-carrier set, P _a(d-1) be the average power content of subcarrier in d-1 the sub-carrier set, P _m(d) be maximum power value in the performance number of subcarrier in the set of described subcarrier, A is first parameter preset, and B is second parameter preset.

In conjunction with the 4th kind of possible implementation, in the 5th kind of possible implementation, described processing unit also is used for, and before there is noise in described definite described subcarrier, passes through formula:

Determine the quantity of described subcarrier set the subcarrier in described OFDM symbol to be detected according to default number of elements, wherein, W is the quantity of described subcarrier set, and N is the quantity of the subcarrier in the described OFDM symbol to be detected, and NS is described default number of elements;

Pass through formula:

$P_t=\frac{1}{W}\underset{d=0}{\overset{W-1}{\mathrm{\Σ}}}{P}_a\left(d\right)$

Obtain second average power content; Wherein, described P _tBe described second average power, P _a(d) be described first average power content, d is the sign of described subcarrier set, W is the quantity of described subcarrier set, and described second average power content is the average power content according to all the average power content of subcarrier obtains in the subcarriers set in the described OFDM symbol to be detected;

Described processing unit specifically is used for, and during more than or equal to described first detection threshold value, the design variables value is added 1 in the performance number of determining described subcarrier, and wherein, the initial value of described design variables value is 0;

During more than or equal to described second detection threshold value, described design variables value is added 1 in the performance number of determining described subcarrier;

During more than or equal to described the 3rd detection threshold value and more than or equal to described the 4th detection threshold value, described design variables value is added 1 in the performance number of determining described subcarrier;

Greater than 1 and described second average power content during more than or equal to default power threshold, determine that there is noise in described subcarrier in definite described design variables value.

In conjunction with the 5th kind of possible implementation, in the 6th kind of possible implementation, described processing unit also is used for, in the performance number of determining described subcarrier less than described the 3rd detection threshold value, and/or the performance number of determining described subcarrier is during less than described the 4th detection threshold value, with the zero clearing of described design variables value.

In conjunction with the 5th kind of possible implementation or the 6th kind of possible implementation, in the 7th kind of possible implementation, described processing unit also is used for, after there is noise in definite described subcarrier, whether performance number that continue to determine next subcarrier in the described OFDM symbol to be detected satisfies the noise measuring strategy, and when the performance number of determining the subcarrier of default value does not continuously satisfy the noise measuring strategy, determine the noise measuring result, wherein, described noise measuring result comprises the subcarrier corresponding identification that satisfies the noise measuring strategy, and described next subcarrier comprises the subcarrier that the sign of described subcarrier is added the sign correspondence that obtains after.

By adopting such scheme, noise measuring equipment obtains the performance number of the subcarrier in the orthogonal frequency division multiplex OFDM symbol to be detected, determine the sign of the subcarrier set of this subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of this subcarrier set, when determining that according to this noise measuring threshold value the performance number of this subcarrier satisfies the noise measuring strategy, determine that there is noise in this subcarrier, like this, by OFDM symbol to be detected is divided set, and adopt noise measuring strategy more accurately at each set, even make under the scene of channel fading, also can realize the accurate detection to signal noise, to guarantee the reliable transmission of signal.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, to do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below, apparently, accompanying drawing in describing below only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.

The method schematic diagram of a kind of noise measuring that Fig. 1 provides for the embodiment of the invention;

The schematic flow sheet of a kind of noise detecting method that Fig. 2 provides for the embodiment of the invention;

The structural representation of a kind of noise measuring equipment that Fig. 3 provides for the embodiment of the invention;

The structural representation of the another kind of noise measuring equipment that Fig. 4 provides for the embodiment of the invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that obtains under the creative work prerequisite.

The embodiment of the invention provides a kind of method of noise measuring, and as shown in Figure 1, the executive agent of this method is noise measuring equipment, and this method comprises:

S101, noise measuring equipment obtain the performance number of the subcarrier in the OFDM symbol to be detected.

Particularly, noise measuring equipment is determined sample OFDM symbol from the OFDM symbol that receives, wherein, this sample OFDM symbol is the determined sample symbol of performance number for subcarrier in this OFDM symbol to be detected of acquisition, and passes through formula according to this sample OFDM symbol:

$P\left(n\right)=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{\left|r_{m,n}\right|}^2$

Obtain the performance number of the subcarrier in this OFDM symbol to be detected; Wherein, P (n) is the performance number of the subcarrier in this OFDM symbol to be detected, and M is the quantity of this sample OFDM symbol, and m is the sign of this sample OFDM symbol, and n is the sign of this subcarrier, r _{M, n}Be n subcarrier in m the sample OFDM symbol.

By above-mentioned formula as can be seen, the calculating of the performance number of the subcarrier in the OFDM symbol to be detected is the performance number addition with the subcarrier of same sub-carrier sign correspondence in each sample OFDM symbol, and obtain the ratio of the quantity of the value that obtains after the addition and sample OFDM symbol, thereby obtain the performance number of subcarrier corresponding with this subcarrier sign in the OFDM symbol to be detected, for example, noise measuring equipment receives 4 OFDM symbols, 2 sample OFDM symbols have therefrom been chosen, then with the performance number addition that is designated 0 subcarrier of these 2 sample OFDM symbol sub-carriers, and the value that obtains after the addition compared with the quantity (being above-mentioned 2 OFDM symbols choosing) of sample OFDM symbol, thereby obtain in this OFDM symbol to be detected being designated with this subcarrier the performance number of 0 subcarrier, calculate subcarrier in the OFDM symbol to be detected according to the method described above successively and be designated 1 performance number to the corresponding subcarrier of maximum of subcarrier sign, thereby obtain the performance number of subcarriers all in this OFDM symbol to be detected; Here just illustrate, do not limit.

Need to prove that for the noise of long-time existence, definite sample OFDM symbolic number is more many, the performance number of the subcarrier in the OFDM symbol to be detected that then obtains is more accurate, detection to follow-up noise is also more accurate, still, because the sample OFDM symbol of choosing is more many, the time-delay of noise measuring is just more high, and the complexity of calculating is also more high, thereby causes the burden of system's operation, therefore, for the noise of long-time existence, definite sample OFDM symbol needs the burden of taking into account system operation.Noise for burst need detect noise as soon as possible, is therefore guaranteeing to detect under the condition of noise, and the sample OFDM symbol of determining is more few more good.

In addition, the sign of above-mentioned subcarrier can be the label of subcarrier, for example can to the subcarrier in the OFDM symbol according to 0,1, the order of 2...... carries out label.

S102, noise measuring equipment are determined the sign of the subcarrier set of this subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of this subcarrier set.

Wherein, this sub-carrier set is combined into the set of determining according to default number of elements the subcarrier of this noise measuring equipment in this OFDM symbol to be detected.

Particularly, determine the subcarrier set according to default number of elements the subcarrier of noise measuring equipment in this OFDM symbol to be detected, for example, if default number of elements is 5, subcarrier in then will this OFDM symbol to be detected with 5 as a set, if in this OFDM symbol 10 subcarriers are arranged, then this 10 subcarrier are divided into two set.

Alternatively, the sign of the subcarrier in each subcarrier set that noise measuring equipment is divided can be continuous, for example, comprise 10 subcarriers in this OFDM symbol to be detected, label is designated as 0,1 respectively, 2......9, and is 5 to be divided into 2 set according to default number of elements, label is designated as 0 and 1 respectively, wherein, label is that 0 set comprises that label is 0 to 4 subcarrier, and label is that 1 set comprises that label is 5 to 9 subcarrier.Certainly, the sign of the subcarrier in the set of each subcarrier also can be discontinuous, as with label be 0,2,4,6 and 8 subcarrier as a set, as a set, the present invention does not limit this with label 1,3,5,7 and 9.

In addition, if the default number of elements of determining can't guarantee on average to divide the subcarrier in the OFDM symbol, then after definite subcarrier set, remaining subcarrier is divided in the subcarrier set of having determined, for example, if default number of elements is 3, if in this OFDM symbol 10 subcarriers are arranged, then according to default number of elements these 10 subcarriers are divided into 3 set, at this moment, also remain 1 subcarrier, then this subcarrier is divided in any in above-mentioned 3 set.

Need to prove that the subcarrier set of determining comprises the sign of subcarrier set, for example, can be the label of subcarrier set, as according to 0,1, the order of 2...... carries out label.

Further, the ratio of the quantity of the performance number sum of whole subcarriers and the subcarrier in the set of this subcarrier obtained first average power content in noise measuring equipment was gathered by the subcarrier of the sign correspondence of this subcarrier set, and from the performance number of the interior subcarrier of this subcarrier set, determine maximum power value, and obtain detection threshold value according to this first average power content and this maximum power value.

Wherein, this first average power content is the average power content of subcarrier in this subcarrier set.

Particularly, noise measuring equipment obtains first detection threshold according to this first average power content

A·P _a(d-1)

Value: wherein, this first detection threshold value is:

Noise measuring equipment obtains second detection threshold value according to this first average power content: wherein, this second detection threshold value is: AP _a(d+1)

Noise measuring equipment obtains the 3rd detection threshold value according to this first average power content: wherein, the 3rd detection threshold value is: AP _a(d)

Noise measuring equipment obtains the 4th detection threshold value according to this maximum power value: wherein, the 4th detection threshold value is:

Wherein, d is the sign of this subcarrier set, P _a(d) be this first average power content, P _a(d+1) be the average power content of subcarrier in d+1 the sub-carrier set, P _a(d-1) be the average power content of subcarrier in d-1 the sub-carrier set, P _m(d) be the maximum power value in the performance number of subcarrier in this subcarrier set, A is first parameter preset, and B is second parameter preset.

S103, noise measuring equipment determine that there is noise in this subcarrier when determining that according to this noise measuring threshold value the performance number of this subcarrier satisfies the noise measuring strategy.

Particularly, noise measuring equipment passes through formula before this step S103:

According to presetting the quantity that number of elements determines that this subcarrier is gathered, wherein, W is the quantity of the subcarrier in this OFDM symbol to be detected for the quantity of this subcarrier set, N the subcarrier in this OFDM symbol to be detected, and NS presets number of elements for being somebody's turn to do,

By this formula as can be seen, W carries out value according to the principle that rounds downwards.

Noise measuring equipment passes through formula:

$P_t=\frac{1}{W}\underset{d=0}{\overset{W-1}{\mathrm{\Σ}}}{P}_a\left(d\right)$

Obtain second average power content; Wherein, this P _tBe this second average power, P _a(d) be this first average power content, d is the sign of this subcarrier set, W is the quantity of this subcarrier set, the average power content that this second average power content obtains for the average power content according to subcarrier in all subcarrier is gathered in this OFDM symbol to be detected.

Further, noise measuring equipment determines that this subcarrier exists noise specifically to comprise following 4 steps when determining that according to this noise measuring threshold value the performance number of this subcarrier satisfies the noise measuring strategy:

Step 1, noise measuring equipment during more than or equal to this first detection threshold value, add 1 with the design variables value in the performance number of determining this subcarrier.

Wherein, the initial value of this design variables value is 0.

Step 2, noise measuring equipment during more than or equal to this second detection threshold value, add 1 with this design variables value in the performance number of determining this subcarrier.

Need to prove that the enforcement order of step 1 and step 2 does not limit, and can carry out step 2 earlier yet, carry out step 1 again.

Step 3, noise measuring equipment during more than or equal to the 3rd detection threshold value and more than or equal to the 4th detection threshold value, add 1 with this design variables value in the performance number of determining this subcarrier.

Further, less than the 3rd detection threshold value, and/or the performance number of determining this subcarrier is during less than the 4th detection threshold value, with this design variables value zero clearing in the performance number of determining this subcarrier for noise measuring equipment.

Need to prove, in the above-mentioned steps 1 if noise measuring equipment in the performance number of determining this subcarrier less than this first detection threshold value, perhaps in the above-mentioned steps 2 if noise measuring equipment in the performance number of determining this subcarrier during less than this second detection threshold value, not to the zero clearing of design variables value, for example, noise measuring equipment is in the performance number of determining this subcarrier during more than or equal to this first detection threshold value, the design variables value is added 1, in the performance number of determining this subcarrier during less than this first detection threshold value, then not to this design variables value add 1 and zero clearing handle, but, if this noise measuring equipment in the performance number of determining this subcarrier less than the 3rd detection threshold value, and/or the performance number of determining this subcarrier is during less than the 4th detection threshold value, with this design variables value zero clearing.

Step 4, noise measuring equipment greater than 1 and this second average power content during more than or equal to default power threshold, determine that there is noise in this subcarrier in definite this design variables value.

Example ground, if noise measuring equipment is in the performance number of determining this subcarrier during more than or equal to this first detection threshold value, the design variables value is added 1, and in the performance number of determining this subcarrier during also more than or equal to this second detection threshold value, this design variables value is added 1 again, at this moment, this design variables value is 2, if noise measuring equipment determines that the performance number of this subcarrier is more than or equal to the 3rd detection threshold value and more than or equal to the 4th detection threshold value, then this design variables value is added 1, at this moment, this design variables value is 3, if noise measuring equipment is further determined this second average power content more than or equal to default power threshold, then noise measuring equipment determines that there is noise in this subcarrier.

Further, after there is noise in definite this subcarrier, noise measuring equipment continues to determine whether the performance number of next subcarrier in this OFDM symbol to be detected satisfies the noise measuring strategy, and when the performance number of determining the subcarrier of default value does not continuously satisfy the noise measuring strategy, determine the noise measuring result.

Wherein, this next one subcarrier comprises the subcarrier that the sign of this subcarrier is added the sign correspondence that obtains after, and this noise measuring result comprises the subcarrier corresponding identification that satisfies the noise measuring strategy.

For example, this OFDM symbol to be detected comprises 10 subcarriers, label is designated as 0 respectively, 1,2......9, and be 5 to be divided into 2 set according to default number of elements, label is designated as 0 and 1 respectively, wherein, label is that 0 set comprises that label is 0 to 4 subcarrier, label is that 1 set comprises that label is 5 to 9 subcarrier, if determining label is that 0 set internal label is that 0 subcarrier exists noise, continue to determine then label is whether 1 subcarrier exists noise, and determine successively label is whether 2 to 9 subcarrier exists noise, if determining label is that 1 subcarrier exists noise, and label be 2 and 3 these two (be above-mentioned default value, here two just illustrate) continuous sub-carriers do not satisfy noise measuring strategy (namely not having noise), determine that then this noise measuring result comprises that label is that 0 subcarrier set internal label is that 0 and 1 subcarrier exists noise, and be that 4 subcarrier begins to proceed noise measuring from label, its concrete detection mode and above-mentioned label are that the detection mode of 0 to 3 subcarrier is identical, therefore repeat no more, subcarrier in will this OFDM symbol to be detected all detects to be finished, and carry out noise processed according to the noise measuring result of the subcarrier in this OFDM symbol to be detected, like this, in the OFDM symbol, may determine a plurality of noise measuring results, thereby noise is carried out more accurate processing.

Particularly, it can be that noise measuring equipment is sent to filter apparatus with the noise measuring result and/or carrier wave is put several devices that above-mentioned noise measuring equipment carries out noise processed, filter apparatus generates corresponding filter factor according to the noise measuring result, and according to this filter factor the subcarrier that has noise is carried out filtering and handle, carrier wave is put several devices and will be existed the subcarrier of noise to be set to 0, perhaps this is existed the amplitude of the subcarrier of noise to be set to constant (being applicable to the situation that noise is bigger to the phase effect of this subcarrier), perhaps this is existed the amplitude of the subcarrier of noise to be set to constant, and keep its phase place (being applicable to the situation that noise is less to the phase effect of this subcarrier).

Be the method for noise measuring equipment by adopting above-mentioned executive agent, noise measuring equipment obtains the performance number of the subcarrier in the orthogonal frequency division multiplex OFDM symbol to be detected, determine the sign of the subcarrier set of this subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of this subcarrier set, when determining that according to this noise measuring threshold value the performance number of this subcarrier satisfies the noise measuring strategy, determine that there is noise in this subcarrier, like this, by OFDM symbol to be detected is divided set, and adopt noise measuring strategy more accurately at each set, even make under the scene of channel fading, also can realize the accurate detection to signal noise, to guarantee the reliable transmission of signal.

The embodiment of the invention provides a kind of method of noise measuring, as shown in Figure 2, comprising:

S201, noise measuring equipment are determined sample OFDM symbol from the OFDM symbol that receives.

Wherein, this sample OFDM symbol is for being used for obtaining the determined sample symbol of performance number of subcarrier in this OFDM symbol to be detected.

S202, noise measuring equipment are determined the performance number of the subcarrier in the OFDM symbol to be detected according to this sample OFDM symbol.

Particularly, noise measuring equipment passes through formula according to this sample OFDM symbol:

$P\left(n\right)=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{\left|r_{m,n}\right|}^2$

Obtain the performance number of the subcarrier in this OFDM symbol to be detected; Wherein, P (n) is the performance number of the subcarrier in this OFDM symbol to be detected, and M is the quantity of this sample OFDM symbol, and m is the sign of this sample OFDM symbol, and n is the sign of this subcarrier, r _{M, n}Be n subcarrier in m the sample OFDM symbol.

By above-mentioned formula as can be seen, the calculating of the performance number of the subcarrier in the OFDM symbol to be detected is the performance number addition with the subcarrier of same sub-carrier sign correspondence in each sample OFDM symbol, and obtain the ratio of the quantity of the value that obtains after the addition and sample OFDM symbol, thereby obtain the performance number of subcarrier corresponding with this subcarrier sign in the OFDM symbol to be detected, for example, noise measuring equipment receives 4 OFDM symbols, 2 sample OFDM symbols have therefrom been chosen, then with the performance number addition that is designated 0 subcarrier of these 2 sample OFDM symbol sub-carriers, and the value that obtains after the addition compared with the quantity (being above-mentioned 2 OFDM symbols choosing) of sample OFDM symbol, thereby obtain in this OFDM symbol to be detected being designated with this subcarrier the performance number of 0 subcarrier, calculate subcarrier in the OFDM symbol to be detected according to the method described above successively and be designated 1 performance number to the corresponding subcarrier of maximum of subcarrier sign, thereby obtain the performance number of subcarriers all in this OFDM symbol to be detected; Here just illustrate, do not limit.

Need to prove that for the noise of long-time existence, definite sample OFDM symbolic number is more many, the performance number of the subcarrier in the OFDM symbol to be detected that then obtains is more accurate, detection to follow-up noise is also more accurate, still, because the sample OFDM symbol of choosing is more many, the time-delay of noise measuring is just more high, and the complexity of calculating is also more high, thereby causes the burden of system's operation, therefore, for the noise of long-time existence, definite sample OFDM symbol needs the burden of taking into account system operation.Noise for burst need detect noise as soon as possible, is therefore guaranteeing to detect under the condition of noise, and the sample OFDM symbol of determining is more few more good.

In addition, the sign of above-mentioned subcarrier can be the label of subcarrier, for example can to the subcarrier in the OFDM symbol according to 0,1, the order of 2...... carries out label.

Determine this subcarrier set according to default number of elements S203, the subcarrier of noise measuring equipment in this OFDM symbol to be detected.

Wherein, this sub-carrier set is combined into the set of determining according to default number of elements the subcarrier of this noise measuring equipment in this OFDM symbol to be detected.

Particularly, determine the subcarrier set according to default number of elements the subcarrier of noise measuring equipment in this OFDM symbol to be detected, for example, if default number of elements is 5, subcarrier in then will this OFDM symbol to be detected with 5 as a set, if in this OFDM symbol 10 subcarriers are arranged, then this 10 subcarrier are divided into two set.

Alternatively, the sign of the subcarrier in each subcarrier set that noise measuring equipment is divided can be continuous, for example, comprise 10 subcarriers in this OFDM symbol to be detected, label is designated as 0,1 respectively, 2......9, and is 5 to be divided into 2 set according to default number of elements, label is designated as 0 and 1 respectively, wherein, label is that 0 set comprises that label is 0 to 4 subcarrier, and label is that 1 set comprises that label is 5 to 9 subcarrier.Certainly, the sign of the subcarrier in the set of each subcarrier also can be discontinuous, as with label be 0,2,4,6 and 8 subcarrier as a set, as a set, the present invention does not limit this with label 1,3,5,7 and 9.

In addition, if the default number of elements of determining can't guarantee on average to divide the subcarrier in the OFDM symbol, then after definite subcarrier set, remaining subcarrier is divided in the subcarrier set of having determined, for example, if default number of elements is 3, if in this OFDM symbol 10 subcarriers are arranged, then according to default number of elements these 10 subcarriers are divided into 3 set, at this moment, also remain 1 subcarrier, then this subcarrier is divided in any in above-mentioned 3 set.

S204, noise measuring equipment are determined the sign of the subcarrier set of this subcarrier correspondence.

Wherein, the subcarrier set of determining comprises the sign of subcarrier set, for example, can be the label of subcarrier set, as according to 0,1, the order of 2...... carry out label,

The ratio of the quantity of the performance number sum of whole subcarriers and the subcarrier in the set of this subcarrier obtained first average power content in S205, noise measuring equipment were gathered by the subcarrier of the sign correspondence of this subcarrier set.

Wherein, this first average power content is the average power content of subcarrier in this subcarrier set.

Determine maximum power value the performance number of S206, noise measuring equipment subcarrier in this subcarrier set.

S207, noise measuring equipment obtain first detection threshold value according to this first average power content, second detection threshold value and the 3rd detection threshold value, and obtain the 4th detection threshold value according to this maximum power value.

Wherein, this first detection threshold value is: AP _a(d-1), this second detection threshold value is: AP _a(d+1), the 3rd detection threshold value is: AP _a(d), the 4th detection threshold value is

Wherein, d is the sign of this subcarrier set, P _a(d) be this first average power content, P _a(d+1) be the average power content of subcarrier in d+1 the sub-carrier set, P _a(d-1) be the average power content of subcarrier in d-1 the sub-carrier set, P _m(d) be the maximum power value in the performance number of subcarrier in this subcarrier set, A is first parameter preset, and B is second parameter preset.

S208, noise measuring equipment pass through formula:

Determine the quantity of this subcarrier set the subcarrier in this OFDM symbol to be detected according to default number of elements.

Wherein, W is the quantity of the subcarrier in this OFDM symbol to be detected for the quantity of this subcarrier set, N, and NS was for presetting number of elements.

S209, noise measuring equipment pass through formula:

$P_t=\frac{1}{W}\underset{d=0}{\overset{W-1}{\mathrm{\Σ}}}{P}_a\left(d\right)$

Obtain second average power content.

Wherein, this P _tBe this second average power, P _a(d) be this first average power content, d is the sign of this subcarrier set, W is the quantity of this subcarrier set, the average power content that this second average power content obtains for the average power content according to subcarrier in all subcarrier is gathered in this OFDM symbol to be detected.

S210, noise measuring equipment determine that there is noise in this subcarrier when determining that according to this first detection threshold value, second detection threshold value, the 3rd detection threshold value and the 4th detection threshold value and second average power content performance number of this subcarrier satisfies the noise measuring strategy.

Particularly, this step S210 specifically comprises following 4 steps:

Step 1, noise measuring equipment during more than or equal to this first detection threshold value, add 1 with the design variables value in the performance number of determining this subcarrier.

Wherein, the initial value of this design variables value is 0.

Step 2, noise measuring equipment during more than or equal to this second detection threshold value, add 1 with this design variables value in the performance number of determining this subcarrier.

Need to prove that the enforcement order of step 1 and step 2 does not limit, and can carry out step 2 earlier yet, carry out step 1 again.

Step 3, noise measuring equipment during more than or equal to the 3rd detection threshold value and more than or equal to the 4th detection threshold value, add 1 with this design variables value in the performance number of determining this subcarrier.

Further, less than the 3rd detection threshold value, and/or the performance number of determining this subcarrier is during less than the 4th detection threshold value, with this design variables value zero clearing in the performance number of determining this subcarrier for noise measuring equipment.

Need to prove, in the above-mentioned steps 1 if noise measuring equipment in the performance number of determining this subcarrier less than this first detection threshold value, perhaps in the above-mentioned steps 2 if noise measuring equipment in the performance number of determining this subcarrier during less than this second detection threshold value, not to the zero clearing of design variables value, for example, noise measuring equipment is in the performance number of determining this subcarrier during more than or equal to this first detection threshold value, the design variables value is added 1, in the performance number of determining this subcarrier during less than this first detection threshold value, then not to this design variables value add 1 and zero clearing handle, but, if this noise measuring equipment in the performance number of determining this subcarrier less than the 3rd detection threshold value, and/or the performance number of determining this subcarrier is during less than the 4th detection threshold value, with this design variables value zero clearing.

Step 4, noise measuring equipment greater than 1 and this second average power content during more than or equal to default power threshold, determine that there is noise in this subcarrier in definite this design variables value.

Example ground, if noise measuring equipment is in the performance number of determining this subcarrier during more than or equal to this first detection threshold value, the design variables value is added 1, and in the performance number of determining this subcarrier during also more than or equal to this second detection threshold value, this design variables value is added 1 again, at this moment, this design variables value is 2, if noise measuring equipment determines that the performance number of this subcarrier is more than or equal to the 3rd detection threshold value and more than or equal to the 4th detection threshold value, then this design variables value is added 1, at this moment, this design variables value is 3, if noise measuring equipment is further determined this second average power content more than or equal to default power threshold, then noise measuring equipment determines that there is noise in this subcarrier.

S211, noise measuring equipment continue to determine whether the performance number of next subcarrier in this OFDM symbol to be detected satisfies the noise measuring strategy, and when the performance number of determining the subcarrier of default value does not continuously satisfy the noise measuring strategy, determine the noise measuring result.

Wherein, this next one subcarrier comprises the subcarrier that the sign of this subcarrier is added the sign correspondence that obtains after, and this noise measuring result comprises the subcarrier corresponding identification that satisfies the noise measuring strategy.

For example, this OFDM symbol to be detected comprises 10 subcarriers, label is designated as 0 respectively, 1,2......9, and be 5 to be divided into 2 set according to default number of elements, label is designated as 0 and 1 respectively, wherein, label is that 0 set comprises that label is 0 to 4 subcarrier, label is that 1 set comprises that label is 5 to 9 subcarrier, if determining label is that 0 set internal label is that 0 subcarrier exists noise, continue to determine then label is whether 1 subcarrier exists noise, and determine successively label is whether 2 to 9 subcarrier exists noise, if determining label is that 1 subcarrier exists noise, and label be 2 and 3 these two (be above-mentioned default value, here two just illustrate) continuous sub-carriers do not satisfy noise measuring strategy (namely not having noise), determine that then this noise measuring result comprises that label is that 0 subcarrier set internal label is that 0 and 1 subcarrier exists noise, and be that 4 subcarrier begins to proceed noise measuring from label, its concrete detection mode and above-mentioned label are that the detection mode of 0 to 3 subcarrier is identical, therefore repeat no more, subcarrier in will this OFDM symbol to be detected all detects to be finished, and carry out noise processed according to the noise measuring result of the subcarrier in this OFDM symbol to be detected, like this, in the OFDM symbol, may determine a plurality of noise measuring results, thereby noise is carried out more accurate processing.

Particularly, it can be that noise measuring equipment is sent to filter apparatus with the noise measuring result and/or carrier wave is put several devices that above-mentioned noise measuring equipment carries out noise processed, filter apparatus generates corresponding filter factor according to the noise measuring result, and according to this filter factor the subcarrier that has noise is carried out filtering and handle, carrier wave is put several devices and will be existed the subcarrier of noise to be set to 0, perhaps this is existed the amplitude of the subcarrier of noise to be set to constant (being applicable to the situation that noise is bigger to the phase effect of this subcarrier), perhaps this is existed the amplitude of the subcarrier of noise to be set to constant, and keep its phase place (being applicable to the situation that noise is less to the phase effect of this subcarrier).

Like this, gather by OFDM symbol to be detected is divided, and adopt noise measuring strategy more accurately at each set, even make under the scene of channel fading, also can realize the accurate detection to signal noise, to guarantee the reliable transmission of signal.

Need to prove, for aforesaid each method embodiment, for simple description, so it all is expressed as a series of combination of actions, but those skilled in the art should know, the present invention is not subjected to the restriction of described sequence of movement, because according to the present invention, some step can adopt other orders or carry out simultaneously.Secondly, those skilled in the art also should know, the embodiment described in the specification all belongs to preferred embodiment, and related action and module might not be that the present invention is necessary.

The embodiment of the invention provides a kind of noise measuring equipment 30, as shown in Figure 3, comprising:

Acquiring unit 31 is for the performance number of obtaining the subcarrier in the OFDM symbol to be detected.

Alternatively, this acquiring unit 31 specifically is used for, and determines sample OFDM symbol from the OFDM symbol that receives, and wherein, this sample OFDM symbol is for being used for obtaining the determined sample symbol of performance number of subcarrier in this OFDM symbol to be detected.

Pass through formula according to this sample OFDM symbol:

$P\left(n\right)=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{\left|r_{m,n}\right|}^2$

Obtain the performance number of the subcarrier in this OFDM symbol to be detected; Wherein, P (n) is the performance number of the subcarrier in this OFDM symbol to be detected, and M is the quantity of this sample OFDM symbol, and m is the sign of this sample OFDM symbol, and n is the sign of this subcarrier, r _{M, n}Be n subcarrier in m the sample OFDM symbol.

By above-mentioned formula as can be seen, the calculating of the performance number of the subcarrier in the OFDM symbol to be detected is the performance number addition with the subcarrier of same sub-carrier sign correspondence in each sample OFDM symbol, and obtain the ratio of the quantity of the value that obtains after the addition and sample OFDM symbol, thereby obtain the performance number of subcarrier corresponding with this subcarrier sign in the OFDM symbol to be detected, for example, noise measuring equipment receives 4 OFDM symbols, 2 sample OFDM symbols have therefrom been chosen, then with the performance number addition that is designated 0 subcarrier of these 2 sample OFDM symbol sub-carriers, and the value that obtains after the addition compared with the quantity (being above-mentioned 2 OFDM symbols choosing) of sample OFDM symbol, thereby obtain in this OFDM symbol to be detected being designated with this subcarrier the performance number of 0 subcarrier, calculate subcarrier in the OFDM symbol to be detected according to the method described above successively and be designated 1 performance number to the corresponding subcarrier of maximum of subcarrier sign, thereby obtain the performance number of subcarriers all in this OFDM symbol to be detected; Here just illustrate, do not limit.

Need to prove that for the noise of long-time existence, definite sample OFDM symbolic number is more many, the performance number of the subcarrier in the OFDM symbol to be detected that then obtains is more accurate, detection to follow-up noise is also more accurate, still, because the sample OFDM symbol of choosing is more many, the time-delay of noise measuring is just more high, and the complexity of calculating is also more high, thereby causes the burden of system's operation, therefore, for the noise of long-time existence, definite sample OFDM symbol needs the burden of taking into account system operation.Noise for burst need detect noise as soon as possible, is therefore guaranteeing to detect under the condition of noise, and the sample OFDM symbol of determining is more few more good.

In addition, the sign of above-mentioned subcarrier can be the label of subcarrier, for example can to the subcarrier in the OFDM symbol according to 0,1, the order of 2...... carries out label.

Processing unit 32, the sign that is used for the subcarrier set of definite this subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of this subcarrier set, and when determining that according to this noise measuring threshold value the performance number of the subcarrier that this acquiring unit 31 obtains satisfies the noise measuring strategy, determine that there is noise in this subcarrier.

Wherein, this sub-carrier set is combined into the set of determining according to default number of elements the subcarrier of this noise measuring equipment in this OFDM symbol to be detected.

Particularly, this processing unit 32 also is used for, and before the sign of the subcarrier set of determining this subcarrier correspondence, determines this subcarrier set according to default number of elements the subcarrier in this OFDM symbol to be detected.

For example, if default number of elements is 5, then the interior subcarrier of this OFDM symbol to be detected there are 10 subcarriers as a set as if in this OFDM symbol with 5, then this 10 subcarrier are divided into two set.

Alternatively, the sign of the subcarrier in each subcarrier set that noise measuring equipment is divided can be continuous, for example, comprise 10 subcarriers in this OFDM symbol to be detected, label is designated as 0,1 respectively, 2......9, and is 5 to be divided into 2 set according to default number of elements, label is designated as 0 and 1 respectively, wherein, label is that 0 set comprises that label is 0 to 4 subcarrier, and label is that 1 set comprises that label is 5 to 9 subcarrier.Certainly, the sign of the subcarrier in the set of each subcarrier also can be discontinuous, as with label be 0,2,4,6 and 8 subcarrier as a set, as a set, the present invention does not limit this with label 1,3,5,7 and 9.

In addition, if the default number of elements of determining can't guarantee on average to divide the subcarrier in the OFDM symbol, then after definite subcarrier set, remaining subcarrier is divided in the subcarrier set of having determined, for example, if default number of elements is 3, if in this OFDM symbol 10 subcarriers are arranged, then according to default number of elements these 10 subcarriers are divided into 3 set, at this moment, also remain 1 subcarrier, then this subcarrier is divided in any in above-mentioned 3 set.

Need to prove that the subcarrier set of determining comprises the sign of subcarrier set, for example, can be the label of subcarrier set, as according to 0,1, the order of 2...... carries out label.

Further, this processing unit 32 specifically is used for, in the subcarrier set of the sign correspondence by the set of this subcarrier all the ratio of the quantity of the interior subcarrier of the performance number sum of subcarriers and the set of this subcarrier obtain first average power content, in this subcarrier set, determine maximum power value the performance number of subcarrier, and obtain detection threshold value according to this first average power content and this maximum power value.

Wherein, this first average power content is the average power content of subcarrier in this subcarrier set.

Further, this processing unit specifically is used for, and obtains first detection threshold value according to this first average power content: wherein, this first detection threshold value is: AP _a(d-1)

Obtain second detection threshold value according to this first average power content: wherein, this second detection threshold value is: AP _a(d+1)

Obtain the 3rd detection threshold value according to this first average power content: wherein, the 3rd detection threshold value is: AP _a(d)

Obtain the 4th detection threshold value according to this maximum power value: wherein, the 4th detection threshold value is:

Wherein, d is the sign of this subcarrier set, P _a(d) be this first average power content, P _a(d+1) be the average power content of subcarrier in d+1 the sub-carrier set, P _a(d-1) be the average power content of subcarrier in d-1 the sub-carrier set, P _m(d) be the maximum power value in the performance number of subcarrier in this subcarrier set, A is first parameter preset, and B is second parameter preset.

Further, this processing unit 32 also is used for, and before there is noise in definite this subcarrier, passes through formula:

Determine the quantity that this subcarrier is gathered according to default number of elements the subcarrier in this OFDM symbol to be detected, wherein, W is the quantity of the subcarrier in this OFDM symbol to be detected for the quantity of this subcarrier set, N, and NS was for presetting number of elements; And pass through formula:

$P_t=\frac{1}{W}\underset{d=0}{\overset{W-1}{\mathrm{\Σ}}}{P}_a\left(d\right)$

Obtain second average power content; Wherein, this P _tBe this second average power, P _a(d) be this first average power content, d is the sign of this subcarrier set, W is the quantity of this subcarrier set, the average power content that this second average power content obtains for the average power content according to subcarrier in all subcarrier is gathered in this OFDM symbol to be detected.

This processing unit 32 specifically is used for, and during more than or equal to this first detection threshold value, the design variables value is added 1 in the performance number of determining this subcarrier, and wherein, the initial value of this design variables value is 0;

During more than or equal to this second detection threshold value, this design variables value is added 1 in the performance number of determining this subcarrier;

During more than or equal to the 3rd detection threshold value and more than or equal to the 4th detection threshold value, this design variables value is added 1 in the performance number of determining this subcarrier;

Greater than 1 and this second average power content during more than or equal to default power threshold, determine that there is noise in this subcarrier in definite this design variables value.

Alternatively, this processing unit 32 also is used for, and less than the 3rd detection threshold value, and/or the performance number of determining this subcarrier is during less than the 4th detection threshold value, with this design variables value zero clearing in the performance number of determining this subcarrier.

Example ground, if noise measuring equipment is in the performance number of determining this subcarrier during more than or equal to this first detection threshold value, the design variables value is added 1, and in the performance number of determining this subcarrier during also more than or equal to this second detection threshold value, this design variables value is added 1 again, at this moment, this design variables value is 2, if noise measuring equipment determines that the performance number of this subcarrier is more than or equal to the 3rd detection threshold value and more than or equal to the 4th detection threshold value, then this design variables value is added 1, at this moment, this design variables value is 3, if noise measuring equipment is further determined this second average power content more than or equal to default power threshold, then noise measuring equipment determines that there is noise in this subcarrier.

Alternatively, this processing unit 32 also is used for, after there is noise in definite this subcarrier, continue to determine whether the performance number of next subcarrier in this OFDM symbol to be detected satisfies the noise measuring strategy, and when the performance number of determining the subcarrier of default value does not continuously satisfy the noise measuring strategy, determine the noise measuring result.

Wherein, this noise measuring result comprises the subcarrier corresponding identification that satisfies the noise measuring strategy, and this next one subcarrier comprises the subcarrier that the sign of this subcarrier is added the sign correspondence that obtains after.

For example, this OFDM symbol to be detected comprises 10 subcarriers, label is designated as 0 respectively, 1,2......9, and be 5 to be divided into 2 set according to default number of elements, label is designated as 0 and 1 respectively, wherein, label is that 0 set comprises that label is 0 to 4 subcarrier, label is that 1 set comprises that label is 5 to 9 subcarrier, if determining label is that 0 set internal label is that 0 subcarrier exists noise, continue to determine then label is whether 1 subcarrier exists noise, and determine successively label is whether 2 to 9 subcarrier exists noise, if determining label is that 1 subcarrier exists noise, and label be 2 and 3 these two (be above-mentioned default value, here two just illustrate) continuous sub-carriers do not satisfy noise measuring strategy (namely not having noise), determine that then this noise measuring result comprises that label is that 0 subcarrier set internal label is that 0 and 1 subcarrier exists noise, and be that 4 subcarrier begins to proceed noise measuring from label, its concrete detection mode and above-mentioned label are that the detection mode of 0 to 3 subcarrier is identical, therefore repeat no more, subcarrier in will this OFDM symbol to be detected all detects to be finished, and carry out noise processed like this according to the noise measuring result of the subcarrier in this OFDM symbol to be detected, in the OFDM symbol, may determine a plurality of noise measuring results, thereby noise is carried out more accurate processing.

Particularly, it can be that noise measuring equipment is sent to filter apparatus with the noise measuring result and/or carrier wave is put several devices that above-mentioned noise measuring equipment carries out noise processed, filter apparatus generates corresponding filter factor according to the noise measuring result, and according to this filter factor the subcarrier that has noise is carried out filtering and handle, carrier wave is put several devices and will be existed the subcarrier of noise to be set to 0, perhaps this is existed the amplitude of the subcarrier of noise to be set to constant (being applicable to the situation that noise is bigger to the phase effect of this subcarrier), perhaps this is existed the amplitude of the subcarrier of noise to be set to constant, and keep its phase place (being applicable to the situation that noise is less to the phase effect of this subcarrier).

Adopt above-mentioned noise measuring equipment, noise measuring equipment obtains the performance number of the subcarrier in the orthogonal frequency division multiplex OFDM symbol to be detected, determine the sign of the subcarrier set of this subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of this subcarrier set, when determining that according to this noise measuring threshold value the performance number of this subcarrier satisfies the noise measuring strategy, determine that there is noise in this subcarrier, like this, by OFDM symbol to be detected is divided set, and adopt noise measuring strategy more accurately at each set, even make under the scene of channel fading, also can realize the accurate detection to signal noise, to guarantee the reliable transmission of signal.

Under those skilled in the art can be well understood to, be the convenience described and succinct, the concrete course of work and the description of the noise measuring equipment of foregoing description can not repeat them here with reference to the corresponding process among the preceding method embodiment.

The embodiment of the invention provides a kind of noise measuring equipment 40, and as shown in Figure 4, this noise measuring equipment 40 comprises:

Processor (processor) 41, communication interface (Communications Interface) 42, memory (memory) 43 and communication bus 44; Wherein, described processor 41, described communication interface 42 and described memory 43 are finished mutual communicating by letter by described communication bus 44.

Processor 41 may be a central processor CPU, or specific integrated circuit ASIC (Application Specific Integrated Circuit), or is configured to implement one or more integrated circuits of the embodiment of the invention.

Memory 43 is used for depositing program code, and described program code comprises computer-managed instruction.Memory 43 may comprise the high-speed RAM memory, also may also comprise nonvolatile memory (non-volatile memory), for example at least one magnetic disc store.

Described communication interface 42 is used for the connection communication between these devices of realization.

Described processor 41 executive program codes, be used for obtaining the performance number of the subcarrier in the OFDM symbol to be detected, determine the sign of the subcarrier set of this subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of this subcarrier set, and when determining that according to this noise measuring threshold value the performance number of this subcarrier satisfies the noise measuring strategy, determine that there is noise in this subcarrier, wherein, this sub-carrier set is combined into the set of determining according to default number of elements the subcarrier of this noise measuring equipment in this OFDM symbol to be detected.

Alternatively, this processor 41 also is used for, and before this determines the sign of subcarrier set of this subcarrier correspondence, determines this subcarrier set according to default number of elements the subcarrier in this OFDM symbol to be detected.

Alternatively, this processor 41 specifically is used for, and determines sample OFDM symbol from the OFDM symbol that receives.Wherein, this sample OFDM symbol is for being used for obtaining the determined sample symbol of performance number of subcarrier in this OFDM symbol to be detected.

Pass through formula according to this sample OFDM symbol:

$P\left(n\right)=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{\left|r_{m,n}\right|}^2$

Obtain the performance number of the subcarrier in this OFDM symbol to be detected; Wherein, P (n) is the performance number of the subcarrier in this OFDM symbol to be detected, and M is the quantity of this sample OFDM symbol, and m is the sign of this sample OFDM symbol, and n is the sign of this subcarrier, r _{M, n}Be n subcarrier in m the sample OFDM symbol.

Alternatively, this processor 41 specifically is used for, in the subcarrier set of the sign correspondence by the set of this subcarrier all the ratio of the quantity of the subcarrier in the performance number sum of subcarriers and the set of this subcarrier obtain first average power content, definite maximum power value the performance number of subcarrier in this subcarrier set; Obtain detection threshold value according to this first average power content and this maximum power value.

Wherein, this first average power content is the average power content of subcarrier in this subcarrier set.

Alternatively.This processor 41 specifically is used for, and obtains first detection threshold value according to this first average power content: wherein, this first detection threshold value is: AP _a(d-1)

Obtain second detection threshold value according to this first average power content: wherein, this second detection threshold value is: AP _a(d+1)

Obtain the 3rd detection threshold value according to this first average power content: wherein, the 3rd detection threshold value is: AP _a(d)

Obtain the 4th detection threshold value according to this maximum power value: wherein, the 4th detection threshold value is:

Wherein, d is the sign of this subcarrier set, P _a(d) be this first average power content, P _a(d+1) be the average power content of subcarrier in d+1 the sub-carrier set, P _a(d-1) be the average power content of subcarrier in d-1 the sub-carrier set, P _m(d) be the maximum power value in the performance number of subcarrier in this subcarrier set, A is first parameter preset, and B is second parameter preset.

Alternatively, this preparation implement body is used for, and before there is noise in definite this subcarrier, passes through formula:

Determine the quantity that this subcarrier is gathered according to default number of elements the subcarrier in this OFDM symbol to be detected, wherein, W is the quantity of the subcarrier in this OFDM symbol to be detected for the quantity of this subcarrier set, N, and NS was for presetting number of elements; And pass through formula:

$P_t=\frac{1}{W}\underset{d=0}{\overset{W-1}{\mathrm{\Σ}}}{P}_a\left(d\right)$

Obtain second average power content; Wherein, this P _tBe this second average power, P _a(d) be this first average power content, d is the sign of this subcarrier set, W is the quantity of this subcarrier set, the average power content that this second average power content obtains for the average power content according to subcarrier in all subcarrier is gathered in this OFDM symbol to be detected;

During more than or equal to this first detection threshold value, the design variables value is added 1 in the performance number of determining this subcarrier, wherein, the initial value of this design variables value is 0;

During more than or equal to this second detection threshold value, this design variables value is added 1 in the performance number of determining this subcarrier;

During more than or equal to the 3rd detection threshold value and more than or equal to the 4th detection threshold value, this design variables value is added 1 in the performance number of determining this subcarrier;

Greater than 1 and this second average power content during more than or equal to default power threshold, determine that there is noise in this subcarrier in definite this design variables value.

Alternatively, this processor 41 also is used for, and less than the 3rd detection threshold value, and/or the performance number of determining this subcarrier is during less than the 4th detection threshold value, with this design variables value zero clearing in the performance number of determining this subcarrier.

Alternatively, this processor 41 also is used for, after there is noise in definite this subcarrier, continue to determine whether the performance number of next subcarrier in this OFDM symbol to be detected satisfies the noise measuring strategy, and when the performance number of determining the subcarrier of default value does not continuously satisfy the noise measuring strategy, determine the noise measuring result.

Wherein, this next one subcarrier comprises the subcarrier that the sign of this subcarrier is added the sign correspondence that obtains after, and this noise measuring result comprises the subcarrier corresponding identification that satisfies the noise measuring strategy.

The above; only be the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; can expect easily changing or replacing, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion by described protection range with claim.

Claims (16)

1. the method for a noise measuring is characterized in that, comprising:

Noise measuring equipment obtains the performance number of the subcarrier in the orthogonal frequency division multiplex OFDM symbol to be detected;

Determine the sign of the subcarrier set of described subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of described subcarrier set; Wherein, described sub-carrier set is combined into the set of determining according to default number of elements the subcarrier of described noise measuring equipment in described OFDM symbol to be detected;

When determining that according to described noise measuring threshold value the performance number of described subcarrier satisfies the noise measuring strategy, determine that there is noise in described subcarrier.

2. method according to claim 1 is characterized in that, before the sign that the subcarrier of described definite described subcarrier correspondence is gathered, described method also comprises:

Determine described subcarrier set according to default number of elements the subcarrier in described OFDM symbol to be detected.

3. method according to claim 1 and 2 is characterized in that, the performance number that described noise measuring equipment obtains the subcarrier in the OFDM symbol to be detected comprises:

Determine sample OFDM symbol from the OFDM symbol that receives, wherein, described sample OFDM symbol is for being used for obtaining the determined sample symbol of performance number of subcarrier in the described OFDM symbol to be detected;

Pass through formula according to described sample OFDM symbol:

$P\left(n\right)=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{\left|r_{m,n}\right|}^2$

Obtain the performance number of the subcarrier in the described OFDM symbol to be detected; Wherein, P (n) is the performance number of the subcarrier in the described OFDM symbol to be detected, and M is the quantity of described sample OFDM symbol, and m is the sign of described sample OFDM symbol, and n is the sign of described subcarrier, r _{M, n}Be n subcarrier in m the sample OFDM symbol.

4. method according to claim 3 is characterized in that, the described sign of determining the subcarrier set of described subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of described subcarrier set and comprise:

In the subcarrier set of the sign correspondence by the set of described subcarrier all the ratio of the quantity of the interior subcarrier of the performance number sum of subcarriers and the set of described subcarrier obtain first average power content, wherein, described first average power content is the average power content of subcarrier in the described subcarrier set;

In described subcarrier set, determine maximum power value the performance number of subcarrier;

Obtain detection threshold value according to described first average power content and described maximum power value.

5. method according to claim 4 is characterized in that, describedly obtains the noise measuring threshold value according to described first average power content and described maximum power value and comprises:

Obtain first detection threshold value according to described first average power content: wherein, described first detection threshold value is: AP _a(d-1)

Obtain second detection threshold value according to described first average power content: wherein, described second detection threshold value is: AP _a(d+1)

Obtain the 3rd detection threshold value according to described first average power content: wherein, described the 3rd detection threshold value is: AP _a(d)

Obtain the 4th detection threshold value according to described maximum power value: wherein, described the 4th detection threshold value is:

Wherein, d is the sign of described subcarrier set, P _a(d) be described first average power content, P _a(d+1) be the average power content of subcarrier in d+1 the sub-carrier set, P _a(d-1) be the average power content of subcarrier in d-1 the sub-carrier set, P _m(d) be maximum power value in the performance number of subcarrier in the set of described subcarrier, A is first parameter preset, and B is second parameter preset.

6. method according to claim 5 is characterized in that, described before there is noise in definite described subcarrier, described method also comprises:

Pass through formula:

Determine the quantity of described subcarrier set the subcarrier in described OFDM symbol to be detected according to default number of elements, wherein, W is the quantity of described subcarrier set, and N is the quantity of the subcarrier in the described OFDM symbol to be detected, N _SBe described default number of elements;

Pass through formula:

$P_t=\frac{1}{W}\underset{d=0}{\overset{W-1}{\mathrm{\Σ}}}{P}_a\left(d\right)$

Obtain second average power content; Wherein, described P _tBe described second average power, P _a(d) be described first average power content, d is the sign of described subcarrier set, W is the quantity of described subcarrier set, and described second average power content is the average power content according to all the average power content of subcarrier obtains in the subcarriers set in the described OFDM symbol to be detected;

Described when determining that according to described noise measuring threshold value the performance number of described subcarrier satisfies the noise measuring strategy, determine that described subcarrier exists noise to comprise:

During more than or equal to described first detection threshold value, the design variables value is added 1 in the performance number of determining described subcarrier, wherein, the initial value of described design variables value is 0;

During more than or equal to described second detection threshold value, described design variables value is added 1 in the performance number of determining described subcarrier;

During more than or equal to described the 3rd detection threshold value and more than or equal to described the 4th detection threshold value, described design variables value is added 1 in the performance number of determining described subcarrier;

Greater than 1 and described second average power content during more than or equal to default power threshold, determine that there is noise in described subcarrier in definite described design variables value.

7. method according to claim 6 is characterized in that, less than described the 3rd detection threshold value, and/or the performance number of determining described subcarrier is during less than described the 4th detection threshold value, with the zero clearing of described design variables value in the performance number of determining described subcarrier.

8. according to claim 6 or 7 described methods, it is characterized in that after there was noise in definite described subcarrier, described method also comprised:

Whether performance number that continue to determine next subcarrier in the described OFDM symbol to be detected satisfies the noise measuring strategy; Wherein, described next subcarrier comprises the subcarrier that the sign of described subcarrier is added the sign correspondence that obtains after;

When the performance number of determining the subcarrier of default value does not continuously satisfy the noise measuring strategy, determine the noise measuring result, wherein, described noise measuring result comprises the subcarrier corresponding identification that satisfies the noise measuring strategy.

9. a noise measuring equipment is characterized in that, comprising:

Acquiring unit is for the performance number of obtaining the subcarrier in the orthogonal frequency division multiplex OFDM symbol to be detected;

Processing unit, the sign that is used for the subcarrier set of definite described subcarrier correspondence, and obtain corresponding noise measuring threshold value according to the sign of described subcarrier set, and when determining that according to described noise measuring threshold value the performance number of the subcarrier that described acquiring unit obtains satisfies the noise measuring strategy, determine that there is noise in described subcarrier; Wherein, described sub-carrier set is combined into the set of determining according to default number of elements the subcarrier of described noise measuring equipment in described OFDM symbol to be detected.

10. equipment according to claim 9, it is characterized in that, described processing unit also is used for, and before the sign of the described subcarrier set of determining described subcarrier correspondence, determines described subcarrier set according to default number of elements the subcarrier in described OFDM symbol to be detected.

11. according to claim 9 or 10 described equipment, it is characterized in that, described acquiring unit specifically is used for, from the OFDM symbol that receives, determine sample OFDM symbol, wherein, described sample OFDM symbol is for be used for obtaining the determined sample symbol of performance number of subcarrier in the described OFDM symbol to be detected;

Pass through formula according to described sample OFDM symbol:

$P\left(n\right)=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{\left|r_{m,n}\right|}^2$

Obtain the performance number of the subcarrier in the described OFDM symbol to be detected; Wherein, P (n) is the performance number of the subcarrier in the described OFDM symbol to be detected, and M is the quantity of described sample OFDM symbol, and m is the sign of described sample OFDM symbol, and n is the sign of described subcarrier, r _{M, n}Be n subcarrier in m the sample OFDM symbol.

12. method according to claim 11, it is characterized in that, described processing unit specifically is used for, in the subcarrier set of the sign correspondence by the set of described subcarrier all the ratio of the quantity of the interior subcarrier of the performance number sum of subcarriers and the set of described subcarrier obtain first average power content, in described subcarrier set, determine maximum power value the performance number of subcarrier, and obtain detection threshold value according to described first average power content and described maximum power value, wherein, described first average power content is the average power content of subcarrier in the described subcarrier set.

13. equipment according to claim 12 is characterized in that, described processing unit specifically is used for, and obtains first detection threshold value according to described first average power content: wherein, described first detection threshold value is: AP _a(d-1)

Obtain second detection threshold value according to described first average power content: wherein, described second detection threshold value is: AP _a(d+1)

Obtain the 3rd detection threshold value according to described first average power content: wherein, described the 3rd detection threshold value is: AP _a(d)

Obtain the 4th detection threshold value according to described maximum power value: wherein, described the 4th detection threshold value is:

Wherein, d is the sign of described subcarrier set, P _a(d) be described first average power content, P _a(d+1) be the average power content of subcarrier in d+1 the sub-carrier set, P _a(d-1) be the average power content of subcarrier in d-1 the sub-carrier set, P _m(d) be maximum power value in the performance number of subcarrier in the set of described subcarrier, A is first parameter preset, and B is second parameter preset.

14. equipment according to claim 13 is characterized in that, described processing unit also is used for, and before there is noise in described definite described subcarrier, passes through formula:

Determine the quantity of described subcarrier set the subcarrier in described OFDM symbol to be detected according to default number of elements, wherein, W is the quantity of described subcarrier set, and N is the quantity of the subcarrier in the described OFDM symbol to be detected, N _SBe described default number of elements;

Pass through formula:

$P_t=\frac{1}{W}\underset{d=0}{\overset{W-1}{\mathrm{\Σ}}}{P}_a\left(d\right)$

Obtain second average power content; Wherein, described P _tBe described second average power, P _a(d) be described first average power content, d is the sign of described subcarrier set, W is the quantity of described subcarrier set, and described second average power content is the average power content according to all the average power content of subcarrier obtains in the subcarriers set in the described OFDM symbol to be detected;

Described processing unit specifically is used for, and during more than or equal to described first detection threshold value, the design variables value is added 1 in the performance number of determining described subcarrier, and wherein, the initial value of described design variables value is 0;

During more than or equal to described second detection threshold value, described design variables value is added 1 in the performance number of determining described subcarrier;

During more than or equal to described the 3rd detection threshold value and more than or equal to described the 4th detection threshold value, described design variables value is added 1 in the performance number of determining described subcarrier;

Greater than 1 and described second average power content during more than or equal to default power threshold, determine that there is noise in described subcarrier in definite described design variables value.

15. equipment according to claim 14, it is characterized in that described processing unit also is used for, in the performance number of determining described subcarrier less than described the 3rd detection threshold value, and/or the performance number of determining described subcarrier is during less than described the 4th detection threshold value, with the zero clearing of described design variables value.

16. according to claim 14 or 15 described equipment, it is characterized in that, described processing unit also is used for, after there is noise in definite described subcarrier, whether performance number that continue to determine next subcarrier in the described OFDM symbol to be detected satisfies the noise measuring strategy, and when the performance number of determining the subcarrier of default value does not continuously satisfy the noise measuring strategy, determine the noise measuring result, wherein, described noise measuring result comprises the subcarrier corresponding identification that satisfies the noise measuring strategy, and described next subcarrier comprises the subcarrier that the sign of described subcarrier is added the sign correspondence that obtains after.

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