CN105392201B - A kind of bandwidth determination method and device based on 802.11n - Google Patents
A kind of bandwidth determination method and device based on 802.11n Download PDFInfo
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- CN105392201B CN105392201B CN201510756461.6A CN201510756461A CN105392201B CN 105392201 B CN105392201 B CN 105392201B CN 201510756461 A CN201510756461 A CN 201510756461A CN 105392201 B CN105392201 B CN 105392201B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04W72/04—Wireless resource allocation
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- H04W72/0473—Wireless resource allocation based on the type of the allocated resource the resource being transmission power
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
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- H—ELECTRICITY
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- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/50—Allocation or scheduling criteria for wireless resources
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Abstract
The invention discloses a kind of bandwidth determination method and device based on 802.11n, method is comprising steps of be divided into the 20MHz signal positioned at main channel and the 20MHz signal positioned at auxiliary channel for the 40MHz bandwidth signal received；Main channel signal and auxiliary channel signal are sampled according to certain sampling configuration, energy measuring and OFDM Autocorrelation Detection are carried out to main channel sampled signal and auxiliary channel sampled signal, sample rate conversion is carried out to main channel signal, DSSS cross-correlation test then is carried out to sampled signal；If determine main channel and auxiliary channel by energy measuring and OFDM Autocorrelation Detection while receiving ofdm signal, then channel response energy measuring is carried out to main channel sampled signal and auxiliary channel sampled signal；Signal bandwidth is determined according to testing result.The present invention carries out channel response energy measuring to main channel sampled signal and auxiliary channel sampled signal, improves the reliability of 802.11n signal bandwidth judgement when energy measuring and OFDM Autocorrelation Detection show that main channel and auxiliary channel receive ofdm signal simultaneously.
Description
Technical field
The present invention relates to fields of communication technology, and in particular to a kind of bandwidth determination method and device based on 802.11n.
Background technique
802.11n agreement allows the network equipment to send data using two adjacent 20MHz channels, that is, 40MHz channel, together
When, in order to be compatible with traditional equipment, when 802.11n equipment work in 40MHz channel, need to have and send and receive 20MHz band
The ability of bandwidth signals.When equipment is in 40MHz operating mode, it is necessary to correctly judge the bandwidth of 802.11 signals, Cai Nengjin first
Row reception processing.
The prior art, for small energy signal, passes through shift frequency and low-pass filter based on the bandwidth determination method of 802.11n
The signal of major-minor channel is obtained, carrier sense, last root are carried out to 40MHz signal, main channel signal and auxiliary channel signal respectively
According to the bandwidth of result judgement useful signal；For big energy signal, then letter is carried out again after carrying out an AGC adjustment and preamble detecting
Number bandwidth detection.
The shortcomings that prior art determination method, is, if signal is 20MHz and exists in auxiliary channel short with ofdm signal
The identical interference of training sequence period, then bandwidth decision logic can generate erroneous judgement, once erroneous judgement, just can not carry out just signal
Really demodulation.
Summary of the invention
The technical problem to be solved in the present invention is that in view of the deficiencies of the prior art, providing a kind of band based on 802.11n
Wide determination method and device overcome prior art 802.11n signal bandwidth determination method to be easy to produce erroneous judgement, reliability not high
Defect.
The present invention to solve above-mentioned technical problem used by technical solution are as follows:
A kind of bandwidth determination method based on 802.11n, comprising steps of
A1, the 40MHz bandwidth signal received is divided into positioned at the 20MHz signal of main channel and positioned at auxiliary channel
20MHz signal；
A2, main channel signal and auxiliary channel signal are sampled according to certain sampling configuration, to main channel sampled signal
Energy measuring and OFDM Autocorrelation Detection are carried out with auxiliary channel sampled signal, sample rate conversion is carried out to main channel signal, then
DSSS cross-correlation test is carried out to sampled signal；
If A3, by energy measuring and OFDM Autocorrelation Detection, determines main channel and auxiliary channel while receiving OFDM
Signal then carries out channel response energy measuring to main channel sampled signal and auxiliary channel sampled signal；
A4, signal bandwidth is determined according to testing result.
According to an embodiment of the invention, step A4 is comprising steps of if by energy measuring and OFDM Autocorrelation Detection,
Determination only receive ofdm signal in main channel, then determine signal for ofdm signal, bandwidth 20MHz, and be located at main channel.
According to an embodiment of the invention, step A4 is comprising steps of if by energy measuring and OFDM Autocorrelation Detection,
Determination only receive ofdm signal in auxiliary channel, then determine signal for ofdm signal, bandwidth 20MHz, and be located at auxiliary channel.
According to an embodiment of the invention, step A4 is comprising steps of if determine bandwidth by channel response energy measuring
For 40M, then determine signal for ofdm signal, bandwidth 40MHz.
According to an embodiment of the invention, step A4 is comprising steps of if determine bandwidth by channel response energy measuring
For 20M, then determine signal for ofdm signal, bandwidth 20MHz, and be located at main channel.
According to an embodiment of the invention, step A4 by the determination of DSSS cross-correlation test comprising steps of if receive
DSSS signal, then determine signal for DSSS signal, and be located at main channel.
According to an embodiment of the invention, step A1 is comprising steps of the 40MHz that will be received by frequency conversion and low-pass filtering
Bandwidth signal is divided into the 20MHz signal positioned at main channel and the 20MHz signal positioned at auxiliary channel.
According to an embodiment of the invention, the sampling configuration is set as down-sampled.
A kind of bandwidth decision maker based on 802.11n, including frequency conversion and filter module, sampling module, signal detection mould
Block and bandwidth judgment module, the frequency conversion and filter module, the sampling module, the signal detection module and the bandwidth judgment module according to
Secondary to be connected, the frequency conversion and filter module are used to that the 40MHz bandwidth signal received to be divided into position by frequency conversion and low-pass filtering
20MHz signal in main channel and the 20MHz signal positioned at auxiliary channel, the sampling module are used for according to certain sampling configuration to master
Channel signal and auxiliary channel signal are sampled, which is used for main channel sampled signal and auxiliary channel sampling letter
Number energy measuring and OFDM Autocorrelation Detection are carried out, sample rate conversion is carried out to main channel signal, then sampled signal is carried out
DSSS cross-correlation test, if determine main channel and auxiliary channel by energy measuring and OFDM Autocorrelation Detection while receiving
Ofdm signal, then carry out channel response energy measuring to main channel sampled signal and auxiliary channel sampled signal, which judges mould
Block is for determining signal bandwidth according to sampled signal testing result.
According to an embodiment of the invention, the signal detection module includes channel response energy detection module.
Implement technical solution of the present invention, has the advantages that the present invention is examined in energy measuring and OFDM auto-correlation
When surveying display main channel and auxiliary channel while receiving ofdm signal, main channel sampled signal and auxiliary channel sampled signal are carried out
Channel response energy measuring improves the reliability of 802.11n signal bandwidth judgement.
Detailed description of the invention
It is specifically described the present invention below with reference to attached drawing and in conjunction with example, advantages of the present invention and implementation will
It is more obvious, wherein content only for the purpose of explanation of the present invention shown in attached drawing, without constitute to it is of the invention in all senses
On limitation, in the accompanying drawings:
Fig. 1 is 802.11n signal frame structure schematic diagram；
Fig. 2 is flow chart of the present invention；
Fig. 3 is signal bandwidth decision flow chart of the present invention；
Fig. 4 is upconversion operation schematic diagram of the present invention；
Fig. 5 is channel response energy measuring schematic diagram of the present invention；
Fig. 6 is bandwidth decision maker module map of the present invention；
Fig. 7 is bandwidth decision maker embodiment schematic diagram of the present invention.
Specific embodiment
As shown in Fig. 2, the present invention is based on the bandwidth determination methods of 802.11n, comprising steps of
S101, the 40MHz bandwidth signal received is divided into positioned at the 20MHz signal of main channel and positioned at auxiliary channel
20MHz signal；
S102, main channel signal and auxiliary channel signal are sampled according to certain sampling configuration, main channel is sampled and is believed
Number and auxiliary channel sampled signal carry out energy measuring and OFDM Autocorrelation Detection, sample rate conversion is carried out to main channel signal, so
DSSS cross-correlation test is carried out to sampled signal afterwards；
If S103, by energy measuring and OFDM Autocorrelation Detection, determines main channel and auxiliary channel while receiving
Ofdm signal then carries out channel response energy measuring to main channel sampled signal and auxiliary channel sampled signal；
S104, signal bandwidth is determined according to testing result.
If as shown in figure 3, according to an embodiment of the invention, when determining according to testing result signal bandwidth by
Energy measuring and OFDM Autocorrelation Detection, determination only receive ofdm signal in main channel, then determine signal for ofdm signal, band
Width is 20MHz, and is located at main channel.If determination is only received in auxiliary channel by energy measuring and OFDM Autocorrelation Detection
Ofdm signal, then determine signal for ofdm signal, bandwidth 20MHz, and be located at auxiliary channel.If examined by channel response energy
Survey determine bandwidth be 40M, then determine signal for ofdm signal, bandwidth 40MHz.If determined by channel response energy measuring
Bandwidth is 20M, then determine signal for ofdm signal, bandwidth 20MHz, and be located at main channel.If examined by DSSS cross-correlation
Survey determination receives DSSS signal, then determine signal for DSSS signal, and be located at main channel.According to an embodiment of the invention, passing through
The 40MHz bandwidth signal received is divided into positioned at the 20MHz signal of main channel and positioned at auxiliary channel by frequency conversion and low-pass filtering
20MHz signal.Sampling configuration can be set to down-sampled.
As shown in Figure 6 and Figure 7, it the present invention is based on the bandwidth decision maker of 802.11n, including frequency conversion and filter module, adopts
Egf block, signal detection module and bandwidth judgment module, frequency conversion and filter module, sampling module, signal detection module and bandwidth
Judgment module is sequentially connected, the 40MHz bandwidth signal of frequency conversion and filter module for will be received by frequency conversion and low-pass filtering
It is divided into the 20MHz signal positioned at the 20MHz signal of main channel and positioned at auxiliary channel, sampling module is used for according to certain sampling mould
Formula samples main channel signal and auxiliary channel signal, and signal detection module is for adopting main channel sampled signal and auxiliary channel
Sample signal carries out energy measuring and OFDM Autocorrelation Detection, sample rate conversion is carried out to main channel signal, then to sampled signal
DSSS cross-correlation test is carried out, if determine main channel and auxiliary channel by energy measuring and OFDM Autocorrelation Detection while connecing
Ofdm signal is received, then channel response energy measuring, bandwidth judgement are carried out to main channel sampled signal and auxiliary channel sampled signal
Module is for determining signal bandwidth according to sampled signal testing result.According to an embodiment of the invention, signal detection mould
Block includes channel response energy detection module.
As shown in Figure 1,802.11n agreement, based on OFDM physical layer, the permission network equipment uses two adjacent
20MHz channel, that is, 40MHz channel sends data, meanwhile, in order to be compatible with traditional equipment, when the work of 802.11n equipment is believed in 40MHz
When road, the ability for sending and receiving 20MHz bandwidth signal is needed to have.When using 40MHz channel, 20MHz bandwidth signal and
The example of 40MHz bandwidth signal is as shown in Figure 1 (main channel is located above).
As shown in figure 4, radiofrequency signal after down coversion and analog-to-digital conversion, obtains the complex base band that sampling rate is 40MHz
Signal x (n)=I (n)+jQ (n), x (n) indicate the sampled value obtained in n-th of moment (i.e. n/40000000 seconds).
As shown in fig. 6, complex baseband signal x (n) is input to main channel frequency-variable module and auxiliary channel frequency-variable module carries out 10MHz
Up-conversion and down coversion.If main channel is located at the top of center frequency point, main channel frequency-variable module carries out down-conversion operation, auxiliary
Channel frequency-variable module carries out frequency up-conversion operation, and the signal after frequency conversion indicates are as follows:
Otherwise, main channel frequency-variable module carries out frequency up-conversion operation, and auxiliary channel frequency-variable module carries out down-conversion operation, after frequency conversion
Signal indicate are as follows:
Two paths of signals Jing Guo frequency conversion is passed through into low-pass filter respectively, only retains the signal of 20MHz bandwidth, then drop is adopted
Sample is 20MHz sample rate.Wherein, the coefficient of filter are as follows: h (n)=- 4,0,12,0, -18,0,28,0, -52,0,162,
256,162,0,-52,0,28,0,-18,0,12,0,-4}
The output signal of filter indicates are as follows:
Output signal after down-sampled indicates are as follows:
z′1(k)=z1(2k)
z′2(k)=z2(2k)
Energy measuring is carried out to the signal after down-sampled.Energy measuring is by calculating the flat of the sampling point in a time window
Equal power obtains, which is traditionally arranged to be ofdm signal short training sequence period, i.e. 16 sampling points.In k-th of sampling point,
Mean power indicates are as follows:
Signal after down-sampled carries out auto-correlation computation (wherein conj indicates conjugate operation):
In k-th of sampling point, for m=-15, -14 ..., 0: if normalized autocorrelation coefficientIt is greater than
0.75 number is more than 8 times, it is considered that detecting ofdm signal in main channel；If normalized autocorrelation coefficientNumber be more than 8 times, it is considered that detecting ofdm signal in auxiliary channel.When main channel and auxiliary channel are same
When detecting ofdm signal, start channel response energy detection module, and calculate following metric as reference energy:
Channel response energy detection module first by main channel 20MHz signal and auxiliary channel 20MHz signal respectively with local
Sequence carries out cross-correlation.Local sequence LTFtBy the inverse Fourier transform (IFFT) and 32 sampling points of cyclic shift of following sequence
It obtains, length 64:[0,1, -1, -1,1,1, -1,1, -1,1, -1, -1, -1, -1, -1,1,1, -1, -1,1, -1,1, -1,1,
1,1,1,0,0,0,0,0,0,0,0,0,0,0,1,1,-1,-1,1,1,-1,1,-1,1,1,1,1,1,1,-1,-1,1,1,-1,
1,-1,1,1,1,1]
The cross-correlation calculation of main channel and auxiliary channel, output signal indicate are as follows:
Calculate the energy value of a time window (16 sampling points) interior cross-correlation:
Meanwhile calculating the energy value of main channel and auxiliary channel on 64 sampling points:
If in p-th of sampling point, Echan,1(p)>32*E1,ref, then finding E since sampling point pchan,1(p),Echan,1(p
+1),...,Echan,1(p+16) maximum value, the corresponding index q of record maximum value.As shown in Figure 5.
If current demand signal is 40MHz ofdm signal, there is following relationship:
Echan,1(q)≈P1(q)
Echan,2(q)≈P2(q)
That is:
Echan,1(q)/Echan,2(q)≈P1(q)/P2(q)
Therefore, compared as follows:
Echan,1(q)/Echan,2(q)≥0.5*P1(q)/P2(q)
Echan,1(q)/Echan,2(q)≤2*P1(q)/P2(q)
If above-mentioned two condition meets simultaneously, it is believed that signal bandwidth 40MHz.Otherwise it is assumed that signal bandwidth is
20MHz。
While the work of above-mentioned module, signal of the main channel after wave filter (but without down-sampled) is adopted
The conversion of sample rate, the input signal of 40MHz sample rate by first passing through 11 times of over-sampling filtering interpolations, then carry out 10 times it is down-sampled,
Become 44MHz sample rate.
Signal after 11 times of over-samplings indicates are as follows:
Signal after filtering interpolation indicates are as follows:
Wherein, filter coefficient are as follows:
hDSSS(n)=1,2,4,6,8,10,11,11,9,5, -1, -9, -19, -31, -42, -53, -61, -64, -61, -
50,-30,1,41,90,147,209,273,336,393,442,480,503,511,503,480,442,393,336,273,
209,147,90,41,1,-30,-50,-61,-64,-61,-53,-42,-31,-19,-9,-1,5,9,11,11,10,8,6,4,
2,1}
Carry out again 10 times it is down-sampled after signal indicate are as follows:
z′DSSS(k)=zDSSS(10k)
Signal z ' after sample rate conversionDSSS(k) it is input to DSSS coherent detection module, is carried out with local sequence mutual
It closes, wherein local sequence are as follows:
Barker=[+1,0,0,0, -1,0,0,0 ,+1,0,0,0 ,+1,0,0,0, -1,0,0,0 ,+1,0,0,0 ,+1,0,
0,0,+1,0,0,0,-1,0,0,0,-1,0,0,0,-1,0,0,0]
Signal after cross-correlation indicates are as follows:
The average energy of signal is calculated simultaneously:
If sometime, | | XDSSS(k)/11||2>0.5*EDSSS(k), then it is assumed that detect DSSS signal.
Bandwidth judgment module is according to the output of OFDM Autocorrelation Detection, DSSS cross-correlation test and channel response energy measuring
Information judgement receives the bandwidth information of signal.
If the OFDM Autocorrelation Detection module of main channel and auxiliary channel is detected simultaneously by ofdm signal:
If 1) channel response energy measuring bandwidth be 40M, determine signal for ofdm signal, bandwidth 40MHz；
If 2) channel response energy measuring bandwidth is 20M, determine signal for ofdm signal, bandwidth 20MHz, and position
In main channel.
If only detecting ofdm signal in main channel Autocorrelation Detection module, determine signal for ofdm signal, bandwidth
For 20MHz, and it is located at main channel.
If only detecting ofdm signal in auxiliary channel Autocorrelation Detection module, determine signal for ofdm signal, bandwidth
For 20MHz, and it is located at auxiliary channel.
If DSSS cross-correlation test module detects DSSS signal, determine signal for DSSS signal, and be located at main letter
Road.
Otherwise, it is determined that being detected without signal.
Those skilled in the art do not depart from essence and spirit of the invention, can there are many deformation scheme realize the present invention,
The foregoing is merely preferably feasible embodiments of the invention, and not thereby limiting the scope of the invention, all with this
The variation of equivalent structure made by description of the invention and accompanying drawing content, is intended to be included within the scope of the present invention.
Claims (10)
1. a kind of bandwidth determination method based on 802.11n, which is characterized in that comprising steps of
A1, the 40MHz bandwidth signal received is divided into positioned at the 20MHz signal of main channel and positioned at the 20MHz of auxiliary channel
Signal；
A2, main channel signal and auxiliary channel signal are sampled according to certain sampling configuration, to main channel sampled signal and auxiliary
Channel sample signal carries out energy measuring and OFDM Autocorrelation Detection, carries out sample rate conversion to main channel signal, then to adopting
Sample signal carries out DSSS cross-correlation test；
If A3, by energy measuring and OFDM Autocorrelation Detection, determines main channel and auxiliary channel while receiving ofdm signal,
Channel response energy measuring then is carried out to main channel sampled signal and auxiliary channel sampled signal, carries out channel response energy measuring
When, main channel and auxiliary channel cross-correlation calculation are carried out, corresponding cross-correlation energy value is calculated, calculates main channel and auxiliary channel sampling
Point energy value, finds out the maximum value in cross-correlation energy value and records its index value, find out corresponding sampled point according to index value
Energy value；
A4, signal bandwidth is determined according to testing result.
2. the bandwidth determination method according to claim 1 based on 802.11n, which is characterized in that the step A4 includes
Step: if by energy measuring and OFDM Autocorrelation Detection, determination only receives ofdm signal in main channel, then determines signal
For ofdm signal, bandwidth 20MHz, and it is located at main channel.
3. the bandwidth determination method according to claim 2 based on 802.11n, which is characterized in that the step A4 includes
Step: if by energy measuring and OFDM Autocorrelation Detection, determination only receives ofdm signal in auxiliary channel, then determines signal
For ofdm signal, bandwidth 20MHz, and it is located at auxiliary channel.
4. the bandwidth determination method according to claim 3 based on 802.11n, which is characterized in that the step A4 includes
Step: if by channel response energy measuring determine bandwidth be 40M, determine signal for ofdm signal, bandwidth 40MHz.
5. the bandwidth determination method according to claim 4 based on 802.11n, which is characterized in that the step A4 includes
Step: if by channel response energy measuring determine bandwidth be 20M, determine signal for ofdm signal, bandwidth 20MHz,
And it is located at main channel.
6. the bandwidth determination method according to claim 5 based on 802.11n, which is characterized in that the step A4 includes
Step: if by DSSS cross-correlation test determination receive DSSS signal, determine signal for DSSS signal, and be located at main letter
Road.
7. the bandwidth determination method according to claim 6 based on 802.11n, which is characterized in that the step A1 includes
Step: the 40MHz bandwidth signal received is divided into positioned at the 20MHz signal of main channel and position by frequency conversion and low-pass filtering
In the 20MHz signal of auxiliary channel.
8. the bandwidth determination method according to claim 7 based on 802.11n, it is characterised in that: the sampling configuration is set
It is down-sampled.
9. a kind of bandwidth decision maker based on 802.11n, it is characterised in that: including frequency conversion and filter module, sampling module, letter
Number detection module and bandwidth judgment module, the frequency conversion and filter module, the sampling module, the signal detection module and institute
It states bandwidth judgment module to be sequentially connected, the frequency conversion and filter module are used to receive by frequency conversion and low-pass filtering
40MHz bandwidth signal is divided into the 20MHz signal positioned at main channel and the 20MHz signal positioned at auxiliary channel, the sampling module
For sampling according to certain sampling configuration to main channel signal and auxiliary channel signal, the signal detection module is used for master
Channel sample signal and auxiliary channel sampled signal carry out energy measuring and OFDM Autocorrelation Detection, sample to main channel signal
Rate conversion, then carries out DSSS cross-correlation test to sampled signal, if determined by energy measuring and OFDM Autocorrelation Detection
Main channel and auxiliary channel receive ofdm signal simultaneously, then carry out channel to main channel sampled signal and auxiliary channel sampled signal and ring
Energy measuring is answered, when carrying out channel response energy measuring, carries out main channel and auxiliary channel cross-correlation calculation, is calculated corresponding mutual
Energy value is closed, main channel and auxiliary channel sampled point energy value is calculated, finds out the maximum value in cross-correlation energy value and record its rope
Draw value, corresponding sampled point energy value is found out according to index value, the bandwidth judgment module is used to detect according to sampled signal and tie
Fruit determines signal bandwidth.
10. the bandwidth decision maker according to claim 9 based on 802.11n, it is characterised in that: the signal detection mould
Block includes channel response energy detection module.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002073831A1 (en) * | 2001-03-09 | 2002-09-19 | Broadstorm Telecommunications, Inc. | A communication system using ofdm for one direction and dsss for another direction |
| CN101594346A (en) * | 2008-05-28 | 2009-12-02 | 北京中电华大电子设计有限责任公司 | The clear channel assessment that is used for 802.11n equipment |
| CN101984694A (en) * | 2010-10-20 | 2011-03-09 | 苏州中科半导体集成技术研发中心有限公司 | Wireless channel idle detection method based on IEEE802.11n |
| US8155140B1 (en) * | 2008-11-25 | 2012-04-10 | Qualcomm Atheros, Inc. | Collision avoidance for a network system |
| CN102957504A (en) * | 2011-08-31 | 2013-03-06 | 北京中电华大电子设计有限责任公司 | Method and device for judging upper and lower sidebands of 802.11n baseband receiver |
-
2015
- 2015-11-06 CN CN201510756461.6A patent/CN105392201B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002073831A1 (en) * | 2001-03-09 | 2002-09-19 | Broadstorm Telecommunications, Inc. | A communication system using ofdm for one direction and dsss for another direction |
| CN101594346A (en) * | 2008-05-28 | 2009-12-02 | 北京中电华大电子设计有限责任公司 | The clear channel assessment that is used for 802.11n equipment |
| US8155140B1 (en) * | 2008-11-25 | 2012-04-10 | Qualcomm Atheros, Inc. | Collision avoidance for a network system |
| CN101984694A (en) * | 2010-10-20 | 2011-03-09 | 苏州中科半导体集成技术研发中心有限公司 | Wireless channel idle detection method based on IEEE802.11n |
| CN102957504A (en) * | 2011-08-31 | 2013-03-06 | 北京中电华大电子设计有限责任公司 | Method and device for judging upper and lower sidebands of 802.11n baseband receiver |
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