CN103379073B - uplink noise estimation method - Google Patents
uplink noise estimation method Download PDFInfo
- Publication number
- CN103379073B CN103379073B CN201210120706.2A CN201210120706A CN103379073B CN 103379073 B CN103379073 B CN 103379073B CN 201210120706 A CN201210120706 A CN 201210120706A CN 103379073 B CN103379073 B CN 103379073B
- Authority
- CN
- China
- Prior art keywords
- carrier
- sub
- noise
- pilot
- pilot sub
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Mobile Radio Communication Systems (AREA)
- Radio Transmission System (AREA)
Abstract
The invention provides a kind of method that upstream noise is estimated, first the channel response estimation of the pilot sub-carrier of even number sequence number in each group pilot sub-carrier on time slot n and the channel response estimation of pilot sub-carrier on time slot n of odd indexed is utilized in the method, first-order difference operation is carried out respectively on frequency domain, and then utilize first-order difference result to do second differnce again on frequency domain, finally, then based on second differnce result in time domain, third order difference is carried out.Adopt the present invention, the accuracy that upstream noise is estimated when frequency domain Selective intensity is more obvious can be guaranteed.
Description
Technical field
The present invention relates to mobile communication technology, particularly relate to a kind of method that upstream noise is estimated.
Background technology
Noise power estimation is the important component part of LTE system, and the balanced detection of receiving terminal, soft bit decoding, CQI calculate and be unable to do without noise power-value, and the accuracy therefore estimated directly can have influence on the performance of whole system.
Noise Estimation Algorithm comparatively common in ofdm system has two kinds: one does noise at frequency domain to estimate, one does noise in time domain to estimate.
Frequency domain noise algorithm for estimating advantage realizes fairly simple, but needs estimating channel information recovering signal, and owing to being subject to the accuracy impact of channel estimating, when causing low signal-to-noise ratio, noise estimation value is less than normal, and during high s/n ratio, noise estimation value is bigger than normal.
Noise in time domain algorithm for estimating is fourier transformed into time domain by domain channel response, time domain is estimated in noise range, implements more complicated.And the Fourier transform under non-integral multiple sampling can cause the leakage of channel multi-path energy, not only comprise the leakage that noise also has channel multi-path in noise range, and both cannot be separated, thus cause estimating noise to be forbidden.
In order to overcome the problems referred to above existing for above-mentioned two kinds of common noise estimation methods, a kind of method of Difference Calculation noise power is suggested.By repeatedly on time-frequency domain pilot sub-carrier difference remove the residue of channel response, only remaining noise information, and then estimate noise power also more accurate.Existing differential noise algorithm for estimating is chosen adjacent continuous subcarrier composition group and is done first-order difference, then adjacent pilot tone group first-order difference value continues to do second differnce, due to the independence that front and back between pilot tone group are relative, when frequency domain Selective intensity is more obvious, second differnce result meeting legacy CHANNEL response message, causes noise to estimate inaccurate; Existing difference method is also not suitable for the situation of up MU-MIMO in addition, after Received signal strength and the local pilot signal conjugate multiplication of a certain user, the channel response superposition of two users can be obtained, and another user is not mated owing to sending pilot tone and local pilot tone above-mentioned, now this subscriber channel no longer includes correlation on frequency domain, now carry out the channel response value that difference must eliminate this user, cause noise misjudgment.
As can be seen here, there is the noise when frequency domain Selective intensity is more obvious and estimate inaccurate problem in the method for above-mentioned Difference Calculation noise power, and is not also suitable for the situation of up MU-MIMO.
Summary of the invention
In view of this, main purpose of the present invention is a kind of method providing upstream noise to estimate, the method can guarantee the accuracy that noise is estimated.
In order to achieve the above object, the technical scheme that the present invention proposes is:
The method that upstream noise is estimated, the method comprises the following steps:
A, in advance the pilot sub-carrier of system to be divided into groups, wherein, often organizes pilot sub-carrier and comprise default m continuous print pilot sub-carrier, described m for can by the pilot sub-carrier of system total the even number of dividing exactly;
B, for often organizing described pilot sub-carrier, calculate on each time slot n of current sub-frame of uplink, the channel response on each pilot sub-carrier i in this group pilot sub-carrier is estimated
and utilize the pilot sub-carrier of odd indexed in this group pilot sub-carrier described on this time slot n
carry out the first-order difference operation on frequency domain, obtain first-order difference result Δ
n, very, utilize the pilot sub-carrier of even number sequence number in this group pilot sub-carrier described on this time slot n
carry out the first-order difference operation on frequency domain, obtain first-order difference result Δ
n, even;
C, for often organizing described pilot sub-carrier, utilize the described Δ of this group pilot sub-carrier respectively on two time slots of current sub-frame of uplink
n, verywith described Δ
n, even, carry out second differnce operation at frequency domain, and utilize described second differnce result to carry out third order difference operation in time domain, obtain third order difference result Δ, calculate σ
2=| Δ |
2/ 24, by described σ
2be defined as the noise power σ that the described pilot sub-carrier of this group is corresponding
2;
D, calculate the described noise power σ of all described pilot subcarrier sets
2mean value, using the noise power estimation value P of this mean value as current sub-frame of uplink
noise_est.
In sum, the method of estimation of the upstream noise that the present invention proposes, forms strange pilot tone group and even pilot tone group by the pilot sub-carrier extracting odd even position respectively, and then carries out single order and second differnce operation over the frequency domain based on this, so, the precision that noise is estimated can effectively be improved.
Accompanying drawing explanation
Fig. 1 is the schematic flow sheet of the embodiment of the present invention one;
Fig. 2 is a simulation result figure of the present invention.
Embodiment
For making the object, technical solutions and advantages of the present invention clearly, the present invention is described in further detail below in conjunction with the accompanying drawings and the specific embodiments.
Core concept of the present invention is: utilize Difference Calculation method to realize the present invention, with existing Difference Calculation method difference be: when the present invention carries out Difference Calculation on frequency domain, divide into groups according to the parity of pilot sub-carrier sequence number, by the pilot sub-carrier of odd number as one group, using the pilot sub-carrier of even number as one group, and then in odd number group and even number set, on frequency domain, do single order and second differnce respectively.Like this, because the pilot sub-carrier of odd number group and the pilot sub-carrier of even number set exist neighbouring relations, therefore the coverage of these two carrier wave set is also close to identical, like this, just can avoid channel frequency selective fading clearly time the noise estimation value that produces problem bigger than normal, thus the accuracy that noise is estimated can be guaranteed.
Fig. 1 is the schematic flow sheet of the uplink noise estimation method of the embodiment of the present invention one, and as shown in Figure 1, the method comprises the following steps:
Step 101, in advance the pilot sub-carrier of system to be divided into groups, wherein, often organize pilot sub-carrier and comprise default m continuous print pilot sub-carrier.
Described m for can by the pilot sub-carrier of system sum the even number of dividing exactly, specifically can be arranged according to actual needs by those skilled in the art, preferably, described m can be set to 6.
Step 102, for often organizing described pilot sub-carrier, calculate on each time slot n of current sub-frame of uplink, the channel response on each pilot sub-carrier i in this group pilot sub-carrier is estimated
and utilize the pilot sub-carrier of odd indexed in this group pilot sub-carrier described on this time slot n
carry out the first-order difference operation on frequency domain, obtain first-order difference result Δ
n, very, utilize the pilot sub-carrier of even number sequence number in this group pilot sub-carrier described on this time slot n
carry out the first-order difference operation on frequency domain, obtain first-order difference result Δ
n, even.
In this step, in order to reduce the impact of frequency domain Selective intensity on noise estimation accuracy, utilize the pilot sub-carrier of even number sequence number in each group pilot sub-carrier described on time slot n
described in the pilot sub-carrier of odd indexed is on time slot n
first-order difference operation is carried out respectively on frequency domain.Here, described in the pilot sub-carrier by calculating even number sequence number is respectively corresponding
described in corresponding with the pilot sub-carrier of odd indexed
two the result Δs carrying out first-order difference can be guaranteed
n, veryand Δ
n, evencarrier wave coverage close to identical, like this, when utilizing first-order difference result to do second differnce again in subsequent step on frequency domain, just can guarantee when frequency domain Selective intensity is more obvious, no longer legacy CHANNEL response message in second differnce result, and then the accuracy that noise is estimated can be guaranteed.
Preferably, the channel response that least square method (LS criterion) can be adopted to obtain on each pilot sub-carrier i is estimated
Particularly, when the number of users taking a Resource Block in system is single, described in calculating
existing method can be adopted to realize, do not repeat them here.
In addition, the present invention is also applicable in MU-MIMO system.Particularly, when the uplink user number same sub-frame of uplink taking same resource block is two, can be according to
or
obtain described in pilot sub-carrier
wherein said
for the Received signal strength on the n-th time-multiplexed pilot subcarrier i of current sub-frame of uplink, described in
for the pilot signal of first user on pilot sub-carrier i on current sub-frame of uplink n-th time slot, described in
for the pilot signal of second user on pilot sub-carrier i on current sub-frame of uplink n-th time slot, i is pilot sub-carrier number, and n is timeslot number.
It should be noted that, when described system is MU-MIMO system, and when the uplink user number same sub-frame of uplink taking same resource block is two, the pilot tone cyclic shift interval n of described two uplink user
csdifference need to be set to 6.
Preferably, as described m=6, can be according to
obtain described Δ
n, very; According to
obtain described Δ
n, even.
Step 103, for often organizing described pilot sub-carrier, utilize the described Δ of this group pilot sub-carrier respectively on two time slots of current sub-frame of uplink
n, verywith described Δ
n, even, carry out second differnce operation at frequency domain, and utilize described second differnce result to carry out third order difference operation in time domain, obtain third order difference result Δ, calculate σ
2=| Δ |
2/ 24, by described σ
2be defined as the noise power σ that the described pilot sub-carrier of this group is corresponding
2.
In this step, in order to reduce the impact of time domain selectivity decline on noise estimation accuracy, time domain utilizes the Δ of one group of pilot sub-carrier respectively on two time slots of current sub-frame of uplink
n, veryand Δ
n, even, carry out the third order difference operation in time domain.
Preferably, can according to Δ=(Δ
1, very-Δ
1, even)-(Δ
2, very-Δ
2, even) obtain described Δ, wherein, (Δ
1, very-Δ
1, even) and (Δ
2, very-Δ
2, even) be respectively the second differnce operation done on two time slots of current sub-frame of uplink and time slot 1 and time slot 2.
Step 104, calculate the described noise power σ of all described pilot subcarrier sets
2mean value, using the noise power estimation value P of this mean value as current sub-frame of uplink
noise_est.
Particularly, in this step according to P
noise_est=σ
2/ T obtains described P
noise_est, wherein, described T is the pilot subcarrier sets number obtained after described grouping.
Further, in order to the shake of noise decrease estimated value, can smoothing process between subframe after step 104, particularly, following step can be adopted to realize:
According to P
noise_new=λ * P
noise_pre+ (1-λ) P
noise_est, to described P
noise_estsmoothing process, obtains the noise power P after smoothing processing
noise_new.
Wherein, P
noise_prefor the noise power after the smoothing processing that a upper subframe obtains, λ is default smoothing weights, and 0 < λ < 1, those skilled in the art can arrange suitable value according to actual needs particularly.
Below by a simulation result figure (see Fig. 2) of above-described embodiment, further illustrate technique effect of the present invention.
Simulated conditions: ETU channel UE single-shot, antenna (dual polarization) is received in base station 8,20M bandwidth, CU 5 Resource Block (RB).Noise power theoretical value is normalized to 1.
As can be seen from the simulation result in Fig. 2, under above-mentioned simulated conditions, noise estimated result of the present invention is basically stable at theoretical value and equals 1 place, visible, the noise accuracy of estimation that the present invention can obtain higher.
In sum, these are only preferred embodiment of the present invention, be not intended to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (8)
1. a method for upstream noise estimation, it is characterized in that, the method comprises the following steps:
A, in advance the pilot sub-carrier of system to be divided into groups, wherein, often organizes pilot sub-carrier and comprise default m continuous print pilot sub-carrier, described m for can by the pilot sub-carrier of system total the even number of dividing exactly;
B, for often organizing described pilot sub-carrier, calculate on each time slot n of current sub-frame of uplink, the channel response on each pilot sub-carrier i in this group pilot sub-carrier is estimated
and utilize the pilot sub-carrier of odd indexed in this group pilot sub-carrier described on this time slot n
carry out the first-order difference operation on frequency domain, obtain first-order difference result Δ
n, very, utilize the pilot sub-carrier of even number sequence number in this group pilot sub-carrier described on this time slot n
carry out the first-order difference operation on frequency domain, obtain first-order difference result Δ
n, even;
C, for often organizing described pilot sub-carrier, utilize the described Δ of this group pilot sub-carrier respectively on two time slots of current sub-frame of uplink
n, verywith described Δ
n, even, carry out second differnce operation at frequency domain, and utilize second differnce result in time domain according to Δ=(Δ
1, very-Δ
1, even)-(Δ
2, very-Δ
2, even) carry out third order difference operation, obtain third order difference result Δ, wherein, (Δ
1, very-Δ
1, even) and (Δ
2, very-Δ
2, even) be respectively the second differnce operation done on two time slots of current sub-frame of uplink and time slot 1 and time slot 2; Calculate σ
2=| Δ |
2/ 24, by described σ
2be defined as the noise power σ that the described pilot sub-carrier of this group is corresponding
2;
D, calculate the described noise power σ of all pilot subcarrier sets
2mean value, using the noise power estimation value P of this mean value as current sub-frame of uplink
noise_est.
2. method according to claim 1, is characterized in that, comprises further after described steps d:
According to P
noise_new=λ * P
noise_pre+ (1-λ) P
noise_est, to described P
noise_estsmoothing process, obtains the noise power P after smoothing processing
noise_new, wherein, P
noise_prefor the noise power after the smoothing processing that a upper subframe obtains, λ is default smoothing weights, 0 < λ < 1.
3. method according to claim 1, is characterized in that, described m=6.
4. method according to claim 3, is characterized in that, according to
obtain described Δ
n, very.
5. method according to claim 3, is characterized in that, according to
obtain described Δ
n, even.
6. method according to claim 1, is characterized in that, adopts described in least square method calculating in described step b
7. method according to claim 6, is characterized in that, when described system is MU-MIMO system, and when the uplink user number same sub-frame of uplink taking same resource block is two, and the pilot tone cyclic shift interval n of described two uplink user
csdifference be 6.
8. method according to claim 7, is characterized in that, when described system is MU-MIMO system, and when the uplink user number same sub-frame of uplink taking same resource block is two, according to
or
described in the pilot sub-carrier obtaining described odd indexed
wherein said
for the Received signal strength on the n-th time-multiplexed pilot subcarrier i of current sub-frame of uplink, described in
for the pilot signal of first user on pilot sub-carrier i on current sub-frame of uplink n-th time slot, described in
for the pilot signal of second user on pilot sub-carrier i on current sub-frame of uplink n-th time slot.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210120706.2A CN103379073B (en) | 2012-04-23 | 2012-04-23 | uplink noise estimation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210120706.2A CN103379073B (en) | 2012-04-23 | 2012-04-23 | uplink noise estimation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103379073A CN103379073A (en) | 2013-10-30 |
| CN103379073B true CN103379073B (en) | 2016-03-09 |
Family
ID=49463638
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210120706.2A Expired - Fee Related CN103379073B (en) | 2012-04-23 | 2012-04-23 | uplink noise estimation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103379073B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105024955B (en) * | 2015-06-10 | 2018-05-18 | 北京北方烽火科技有限公司 | A kind of noise power estimation method and device |
| CN107347194B (en) * | 2016-05-04 | 2020-05-08 | 大唐移动通信设备有限公司 | Uplink background noise processing method and system |
| CN114337868B (en) * | 2021-12-28 | 2024-06-18 | 北京奕斯伟计算技术股份有限公司 | Channel parameter estimation method, device, electronic equipment and readable storage medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1578290A (en) * | 2003-07-08 | 2005-02-09 | 三星电子株式会社 | System and method for channel estimation in an OFDM mobile communication system |
| CN101335980A (en) * | 2007-06-28 | 2008-12-31 | 华为技术有限公司 | Carrier interference noise ratio measurement method and communication apparatus |
| CN102025426A (en) * | 2009-09-17 | 2011-04-20 | 中兴通讯股份有限公司 | Method and device for estimating carrier to interference plus noise ratio in orthogonal frequency division multiplexing system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100510861B1 (en) * | 2003-01-18 | 2005-08-31 | 디지피아(주) | Training signal determining method in OFDM system and apparatus and method for receiving OFDM signal using the training signal |
-
2012
- 2012-04-23 CN CN201210120706.2A patent/CN103379073B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1578290A (en) * | 2003-07-08 | 2005-02-09 | 三星电子株式会社 | System and method for channel estimation in an OFDM mobile communication system |
| CN101335980A (en) * | 2007-06-28 | 2008-12-31 | 华为技术有限公司 | Carrier interference noise ratio measurement method and communication apparatus |
| CN102025426A (en) * | 2009-09-17 | 2011-04-20 | 中兴通讯股份有限公司 | Method and device for estimating carrier to interference plus noise ratio in orthogonal frequency division multiplexing system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103379073A (en) | 2013-10-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102694763B (en) | Method for assessing integer frequency offset of TD-LTE system | |
| US9544171B2 (en) | Zero insertion for ISI free OFDM reception | |
| CN101547062B (en) | Method and device for correcting frequency deviation | |
| CN103873397B (en) | A kind of new joint time domain and frequency domain OFDM receive channel estimation methods | |
| WO2017050065A1 (en) | Method and apparatus for configuring channel state information-reference signal | |
| CN101904114A (en) | The method and apparatus of IFDMA receiver architecture | |
| CN101438523A (en) | Radio transmitter, radio receiver, and pilot generating method | |
| CN102420796A (en) | Communication terminal, and noise estimation method and device thereof | |
| EP2876837B1 (en) | Method and device of frame synchronization of wireless system and wireless system | |
| CN103997722A (en) | Method and system for demodulation reference signal | |
| CN105007146A (en) | Method for generating precursor symbol in physical frame | |
| CN109565770A (en) | For synchronous method and apparatus | |
| CN102684845B (en) | Multiterminal cooperative communication method for LTE (Long Term Evolution) system | |
| CN102833849B (en) | Positioning method and user equipment | |
| CN103051571A (en) | Doppler shift estimation method for TD-LTE (Time Division Long-Term Evolution) system | |
| CN108989259A (en) | The time offset estimation method and system of wireless comprehensive test instrument narrowband Physical Uplink Shared Channel | |
| CN103379073B (en) | uplink noise estimation method | |
| CN103475605B (en) | Channel estimation methods based on user's DRS (Dedicated Reference Signal) in a kind of 3GPPLTE-A downlink system | |
| CN106789803B (en) | Data communications method, device and base station | |
| CN102761504B (en) | Estimation method for TD-LTE digital relay downlink channel | |
| CN103415067A (en) | Signal-to-noise ratio estimation method based on detection reference signal | |
| CN101815047B (en) | Method and device for mapping demodulation pilots and physical resource block | |
| CN103379070A (en) | RE detection method and apparatus | |
| CN106160969A (en) | A kind of LTE down-going synchronous data launch configuration and method of reseptance | |
| CN103428147B (en) | A kind of method that TDD-LTE system frequency deviation compensates |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20160309 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |