CN104144140B - The method and access device of a kind of reducing PAR of OFDM system - Google Patents
The method and access device of a kind of reducing PAR of OFDM system Download PDFInfo
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- CN104144140B CN104144140B CN201310169155.3A CN201310169155A CN104144140B CN 104144140 B CN104144140 B CN 104144140B CN 201310169155 A CN201310169155 A CN 201310169155A CN 104144140 B CN104144140 B CN 104144140B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2614—Peak power aspects
- H04L27/2618—Reduction thereof using auxiliary subcarriers
Abstract
The present invention relates to the method for peak-to-average force ratio is reduced in a kind of ofdm system, methods described includes：Step 1, inverse fast Fourier transform is carried out to the modulated signal for needing to send, obtains the first time-domain signal set；Step 2, power is searched in the first time-domain signal set and meets the time-domain position of the multiple time-domain signals and the time-domain signal of thresholding in power maximum；Step 3, it is determined that subcarrier in send frequency domain auxiliary signal, and the second time-domain signal of the time-domain position to the auxiliary signal when the power of the first time-domain signal is maximum is reversely adjusted, first time-domain signal is prominent time-domain signal in the multiple time-domain signal；Step 4, the second time-domain signal of the auxiliary signal after adjustment is added with the multiple first time-domain signal, to reduce the peak-to-average force ratio of the modulated signal.Can be realized by the above method reduces the peak-to-average force ratio of modulated signal in ofdm system in the case of lower power consumption and operand.
Description
Technical field
The present invention relates to the communications field, and in particular to a kind of reducing PAR of OFDM system method and
Access device.
Background technology
WLAN（Wireless Local Area Network, WLAN）Technology has the advantages that high-speed access,
It is widely used in mobile network's access field.In WLAN technologies, Orthodoxy Frequency Division Multiplex (Orthogonal Frequency
Division Multiplexing, OFDM) technology, but be due to PFDM peak-to-average power ratio（Peak to Average
Power Ratio, PAPR）It is larger, to power amplifier（(power amplifier, PA）Linear requirements produce influence, because
This needs the PAPR reductions to WLAN ofdm system.
In the prior art, it is using the method remapped that reduction PAPR method is a kind of.By every in signal to sending
Any combination of the corresponding bit of individual symbol carries out exhaustive search, and a kind of minimum bit hytes of PAPR are found wherein
Close.Therefore, for exhaustive every kind of bit combination, it is necessary to very big system power dissipation, also, it is complete optimal in each symbol search
Bit bit combination only has, it is necessary to which the configured information that each symbol is transmitted in sending point could be so that receiving terminal be correctly decoded, and this also increases
The consumption to resource is added.
Another reduction PAPR method is that the amplitude and angle to different pilot signals are adjusted, after adjustment
Each pilot signal carry out IFFT conversion, obtain a time-domain signal set, by time-domain signal set each time domain believe
After number time-domain signal carried out with sending signal after IFFT conversion is added, corresponding PAPR is obtained, the choosing in time-domain signal set
The corresponding pilot signal of the minimum peak-to-average force ratios of PAPR is taken to carry out data transmission.The shortcoming of this kind of scheme is, due to pilot tone candidate knot
Close number larger, it is necessary to travel through whole pilot signals in set, amount of calculation is larger.
The content of the invention
The embodiment of the present invention provides a kind of method of reducing PAR of OFDM system, to realize in relatively low work(
The peak-to-average force ratio of modulated signal in ofdm system is reduced in the case of consumption and operand.
First aspect of the embodiment of the present invention provides a kind of method of reducing PAR of OFDM system, described
Method includes：
Step 1, inverse fast Fourier transform is carried out to the frequency domain symbol signal for needing to send, obtains the first time-domain signal sequence
Row；
Step 2, searched in the first time-domain signal sequence more than the time-domain signal of power threshold and time domain letter
Number time-domain position；
Step 3, frequency domain auxiliary signal is sent in the first subcarrier, the frequency domain auxiliary signal is adjusted, so that
The time-domain position power that the second time-domain signal after the frequency domain auxiliary signal time-frequency conversion is obtained in the first time-domain signal is maximum, side
To on the contrary, first time-domain signal is prominent time-domain signal in the time-domain signal；
Step 4, second time-domain signal of the auxiliary signal after adjustment is added with the first time-domain signal sequence,
To reduce the peak-to-average force ratio of the first time-domain signal sequence.
Based in a first aspect, in the first possible embodiment, also including after the step 4：
Step 5, whether the peak-to-average force ratio after detection reduction meets setting thresholding, is being unsatisfactory for setting the situation of thresholding
Under, using another frequency domain auxiliary signal, and step 3 is performed to step 5, until the peak-to-average force ratio meets setting thresholding or do not had
Available frequency domain auxiliary signal.
Based on first aspect or the first possible embodiment, in second of possible embodiment, the frequency domain
Auxiliary signal be pilot signal or sent in idle sub-carrier be used for reduce the signal of peak-to-average force ratio.
, can at the third in the first possible embodiment or second of possible embodiment based on first aspect
In the embodiment of energy, in the step 3, the frequency domain auxiliary signal is adjusted, including frequency domain adjustment, the adjustment side
Method is to be multiplied by exp to the frequency-region signal of the subcarrier of the frequency domain auxiliary signal（-j*2pi*K/Nc*T）, wherein, K is described
Sub-carrier positions, the T is time-domain position of first time-domain signal in time domain peak power.
The first possible embodiment or second of possible embodiment based on first aspect, in the 4th kind of possibility
Embodiment in, the frequency domain auxiliary signal is adjusted, including time domain adjustment, the method for adjustment is, according to from a left side
To right order, according to first time-domain signal in time-domain position T, the frequency domain after inverse fast Fourier transform is aided in
The corresponding time-domain signal of signal carries out cyclic shift T to the right.
In the first possible embodiment or second of possible embodiment based on first aspect or the third can
The embodiment or the 4th kind of possible embodiment of energy, it is described to exceed power threshold in the 5th kind of possible embodiment
Time-domain signal be specially prominent time-domain signal in the first time-domain signal sequence.
In the first possible embodiment or second of possible embodiment based on first aspect or the third can
The embodiment or the 4th kind of possible embodiment of energy, it is described to exceed power threshold in the 5th kind of possible embodiment
Time-domain signal be specially the maximum time-domain signal of real part in the first time-domain signal sequence.
In the first possible embodiment or second of possible embodiment based on first aspect or the third can
The embodiment or the 4th kind of possible embodiment of energy, it is described to exceed power threshold in the 5th kind of possible embodiment
Time-domain signal be specially the maximum time-domain signal of imaginary part in the first time-domain signal sequence.
Second aspect, the embodiments of the invention provide the access device in a kind of WLAN, the access device bag
Include：
Converter unit, for carrying out inverse fast Fourier transform to the frequency domain symbol signal for needing to send, when obtaining first
Domain signal sequence set；
Searching unit, in the first time-domain signal sequence search more than power threshold time-domain signal and it is described when
The time-domain position of domain signal；
Processing unit, frequency domain auxiliary signal is sent in the first subcarrier, the frequency domain auxiliary signal is adjusted, with
So that the second time-domain signal after the frequency domain auxiliary signal time-frequency conversion is maximum in the time-domain position power of the first time-domain signal,
In the opposite direction, first time-domain signal is prominent time-domain signal in the time-domain signal；
Arithmetic element, to by second time-domain signal of the auxiliary signal after adjustment and the first time-domain signal sequence
Row are added, to reduce the peak-to-average force ratio of the first time-domain signal sequence.
Based on second aspect, in the first possible embodiment, in addition to execution unit, it is described after detection reduction
Whether peak-to-average force ratio meets setting thresholding, in the case where being unsatisfactory for setting thresholding, controls the processing unit and the computing list
Member is repeated, using another frequency domain auxiliary signal, until the peak-to-average force ratio meets setting thresholding or auxiliary without available frequency domain
Help signal.
Based on second aspect or the first possible embodiment, in second of possible embodiment, the frequency domain
Auxiliary signal be pilot tone or sent in idle sub-carrier be used for reduce the signal of peak-to-average force ratio.
The first possible embodiment or second of possible embodiment based on second aspect, may at the third
Embodiment in, the processing unit is adjusted to the frequency domain auxiliary signal, including frequency domain adjustment, the method for adjustment
To be multiplied by exp to the frequency-region signal of the subcarrier of the auxiliary signal（-j*2pi*K/Nc*T）, wherein, K is the subcarrier
Position, the T is first time-domain signal in the position of time domain peak power.
The first possible embodiment or second of possible embodiment based on second aspect, in the 4th kind of possibility
Embodiment in, the processing unit is adjusted to the frequency domain auxiliary signal, specially frequency domain adjust, the adjustment
Method is, according to order from left to right, according to first time-domain signal time domain peak power position T, to quick Fu
In the time-domain signal of auxiliary signal after leaf inverse transformation carry out cyclic shift T to the right.
In the first possible embodiment or second of possible embodiment based on second aspect or the third can
The embodiment or the 4th kind of possible embodiment of energy, it is described to exceed power threshold in the 5th kind of possible embodiment
Time-domain signal be specially prominent time-domain signal in the first time-domain signal sequence.
In the first possible embodiment or second of possible embodiment based on second aspect or the third can
The embodiment or the 4th kind of possible embodiment of energy, it is described to exceed power threshold in the 5th kind of possible embodiment
Time-domain signal be specially the maximum time-domain signal of real part in the first time-domain signal sequence.
In the first possible embodiment or second of possible embodiment based on second aspect or the third can
The embodiment or the 4th kind of possible embodiment of energy, it is described to exceed power threshold in the 5th kind of possible embodiment
Time-domain signal be specially the maximum time-domain signal of imaginary part in the first time-domain signal sequence.
The embodiments of the invention provide a kind of method of reducing PAR of OFDM system, by signal to noise ratio
Reference signal is sent in poor idle sub-carrier as auxiliary signal or in the case where not needing channel estimation by pilot tone
Signal adjusts the phase of auxiliary signal as auxiliary signal, by the reverse maximum of auxiliary signal with needing the modulation of transmission
The peak of signal is adjusted in signal in maximum time-domain signal superposition, the method for neutralizing modulated signal time-domain power, reduction ofdm system
Compare, can also degrade computation complexity, improve signal transacting efficiency.
Brief description of the drawings
Fig. 1 is the flow chart of the method for reducing PAR of OFDM system provided in an embodiment of the present invention；
Fig. 2 is a kind of structure chart of embodiment of access device in WLAN provided in an embodiment of the present invention；
Fig. 3 be WLAN provided in an embodiment of the present invention in another embodiment of access device structure chart.
Embodiment
Below by drawings and examples, technical scheme is described in further detail.
As shown in figure 1, the embodiments of the invention provide one kind to achieve the above object, first aspect present invention provides one
The method of kind of reducing PAR of OFDM system, the executive agent of methods described can be used in WLAN
The access point of user equipment（Access Point, AP）Or WLAN can be accessed in a wireless local area network
Handheld terminal, methods described includes：
Step 1, inverse fast Fourier transform is carried out to the frequency domain symbol signal for needing to send, obtains the first time-domain signal sequence
Row；
It is specific and, access point or access terminal need the data sent, it is necessary to enter in frequency domain to correspondence in an ofdm system
Row modulation, inverse fast Fourier transform is carried out after modulation（Inverse fast Fourier transform, IFFT）, obtain
The time-domain signal of modulated signal, because adjustment signal is carried on different data subcarriers respectively, the frequency-region signal sequence of N points
The time-domain signal sequence for obtaining N points is converted by N points IFFT, these time-domain signal sequences constitute an OFDM symbol.
Step 2, searched in the first time-domain signal sequence more than the time-domain signal of power threshold and time domain letter
Number time-domain position；
Specifically, after the time-domain signal sequence of modulated signal is determined, larger several of power are selected wherein
The position of time-domain signal and these time-domain signals, can also select power to exceed several time-domain signals of setting thresholding, and determine
Time-domain position and complex values when power takes maximum；
Specifically, time-domain signal watt level can be determined by the real and imaginary parts quadratic sum of complex values in time domain, also
The real and imaginary parts of time-domain signal can respectively be contrasted, choose real part maximum absolute value, or imaginary part maximum absolute value when
Domain signal.
Step 3, frequency domain auxiliary signal is sent in the first subcarrier, the frequency domain auxiliary signal is adjusted, so that
The time-domain position power that the second time-domain signal after the frequency domain auxiliary signal time-frequency conversion is obtained in the first time-domain signal is maximum, side
To on the contrary, first time-domain signal is prominent time-domain signal in the time-domain signal；
Specifically, single frequency domain auxiliary signal can be sent in idle sub-carrier, or channel need not carried out
During estimation, pilot tone is reduced into peak-to-average force ratio as frequency domain auxiliary signal, but for these frequency domain auxiliary signals, it is necessary to its phase
Position is adjusted, and makes the maximum position of its reverse amplitude after frequency domain to time domain changes and the position phase of the first time-domain signal
Together.
Step 4, second time-domain signal of the auxiliary signal after adjustment is added with the first time-domain signal sequence,
To reduce the peak-to-average force ratio of the first time-domain signal sequence.
Specifically, in time domain by the complex values of the time-domain signal of the frequency domain auxiliary signal after adjustment, with the first time-domain signal
Complex values be added, because time-domain position is identical, but opposite in phase, therefore the amplitude of adjustment signal is reduced, because peak is equal
It is more in direct ratio than with the maximum power value of modulated signal, thus reached reduction peak-to-average force ratio effect,
But, only by prominent in the frequency domain auxiliary signal and the time-domain signal of frequency-region signal in a subcarrier
Peak-to-average force ratio after time-domain signal neutralization, might not disclosure satisfy that the peak-to-average force ratio threshold value of setting, therefore the system after step 4
Whether the peak-to-average force ratio after detection reduction meets setting thresholding, if having met the peak-to-average force ratio threshold requirement of setting, stops
Only computing, this auxiliary signal is sent together with modulated signal to receiving terminal, conversely, in the case where being unsatisfactory for setting thresholding,
Step 3 is repeated to step 4 from another frequency domain auxiliary signal, in the first time domain sequences, selects next power
Maximum time-domain signal, the operation of peak-to-average force ratio reduction is carried out using the frequency domain auxiliary signal on another subcarrier；If again
After execution, peak-to-average force ratio does not still meet setting thresholding, can select to perform step 3 again to step 4, until not meeting
Set the time-domain signal of thresholding or without available frequency domain auxiliary signal.
By the above embodiments, sent in the poor idle sub-carrier of noise reference signal as auxiliary signal or
Person in the case where not needing channel estimation using pilot signal as auxiliary signal, and adjust the phase of auxiliary signal, will aid in
The reverse maximum of signal is superimposed with maximum time-domain signal in the modulated signal for needing to send, and neutralizes modulated signal time-domain power
The peak-to-average force ratio of signal is adjusted in method, reduction ofdm system, can degrade computation complexity, improve signal transacting efficiency.
In a kind of possible embodiment, in the case where ofdm system uses fractional bandwidth transmission data, generally only
The preferable subcarrier carrying of noise ripple is selected to need the data sent, and the poor subcarrier of noise then turns into idle son and carried
Ripple, therefore, in the present embodiment, transmitting terminal can send auxiliary signal in the poor subcarrier of noise, can reach drop
Low PAPR effect.
Such as 802.11ah systems are under 2MHz bandwidth, and each OFDM symbol of data field has 52 data subcarriers, false
It is located at and only have selected 40 best subcarriers of performance under frequency-selective channel to transmit data, then 12 idle data
Subcarrier can be for progress reduction PAPR, it is assumed that the data for needing to send are modulated with BPSK.
40 data subcarriers are calculated first after IFFT, the time-domain position and complex values of prominent 1 point, and
One group of idle sub-carrier is selected, according to the time-domain position of data tone power maximum, the positive and negative and idle sub- load of real imaginary part
The phase of symbol in the position adjustment idle sub-carrier of ripple so that idle sub-carrier is in the position of data tone power maximum
Take symbol conversely maximum, then calculate the IFFT of this group of idle sub-carrier, recalculate time domain after data investigation idle sub-carrier
Whether signal maximum meets the peak-to-average force ratio threshold requirement of setting, gradually increases idle sub-carrier number if being unsatisfactory for until full
Untill the default PAPR thresholdings of foot or idle sub-carrier number are used completely.
Idle sub-carrier phase is wherein adjusted, makes its reverse maximum identical with the position of prominent data field signal
Method can be frequency domain adjustment, that is,：
Known idle sub-carrier position K and data time domain maximum position are T, and Nc is total sub-carrier number, and pi is pi,
exp（）Natural number e exponent arithmetic symbol is represented, then exp is multiplied by idle sub-carrier frequency-region signal（-j*2pi*K/Nc*T）, and
Minimum principle, which is added, according to the complex values of data maximums selects sign symbol.
Or, be adjusted in time domain, first, calculate one group of idle sub-carrier IFFT time-domain signals, afterwards, according to from
Left-to-right order, according to data time domain maximum position T, cyclic shift T to the right is carried out to the IFFT of the group.It is maximum according to data
The complex values of value are added minimum principle selection sign symbol.
In addition, calculating 40 data subcarriers after IFFT, it can also select to be distinguished with same idle sub-carrier
Several data subcarriers larger to power carry out peak value neutralization, until peak-to-average force ratio meets setting demand, or no satisfaction is set
Determine the data subcarrier of power condition.
In another embodiment, it is assumed that variable period is longer during channel, therefore channel time change is slower, therefore in number
Channel estimation need not be carried out according to the pilot tone in domain, the pilot tone that thus be accordingly used in channel estimation can be with the free time in above-described embodiment
Subcarrier is the same, as the frequency domain auxiliary signal of reduction peak-to-average force ratio, and process is similar with previous embodiment, seldom repeats.
By the above embodiments, sent in the poor idle sub-carrier of noise reference signal as auxiliary signal or
Person in the case where not needing channel estimation using pilot signal as auxiliary signal, and adjust the phase of auxiliary signal, will aid in
The reverse maximum of signal is superimposed with maximum time-domain signal in the modulated signal for needing to send, and neutralizes modulated signal time-domain power
The peak-to-average force ratio of signal is adjusted in method, reduction ofdm system, can degrade computation complexity, improve signal transacting efficiency.
Accordingly, as shown in Fig. 2 the embodiments of the invention provide the access device in a kind of WLAN, the device
It can be the access point in handheld terminal or wlan system（Access point, AP）, described device includes：
Converter unit 201, for carrying out inverse fast Fourier transform to the frequency domain symbol signal for needing to send, obtains first
Time-domain signal sequence；
Searching unit 202, for searching time-domain signal and institute more than power threshold in the first time-domain signal sequence
State the time-domain position of time-domain signal；
Processing unit 203, frequency domain auxiliary signal is sent in the first subcarrier, the frequency domain auxiliary signal is adjusted
It is whole, to cause the second time-domain signal after the frequency domain auxiliary signal time-frequency conversion in the time-domain position power of the first time-domain signal
Maximum, in the opposite direction, first time-domain signal are prominent time-domain signal in the time-domain signal；
Arithmetic element 204, second time-domain signal of the auxiliary signal after adjustment and first time domain to be believed
Number sequence is added, to reduce the peak-to-average force ratio of the first time-domain signal sequence.
In an embodiment of the present invention, the frequency domain auxiliary signal is pilot signal or the use sent in idle sub-carrier
In the reference signal of reduction peak-to-average force ratio.
In the first possible embodiment, described device also includes execution unit, for detecting the arithmetic element
Whether the peak-to-average force ratio after 204 reductions meets setting thresholding, in the case where being unsatisfactory for setting thresholding, controls the processing single
Member 203 and the arithmetic element 204 are repeated, until believing without available subcarrier or the time domain for being not above power threshold
Number.
By the arithmetic element 204 by the second time-domain signal of the frequency domain auxiliary signal after adjustment and first time domain
Signal is added, to reduce the peak-to-average force ratio of the modulated signal, until the peak-to-average force ratio meets setting thresholding or no available frequency domain
Auxiliary signal.
In the foregoing embodiments, 203 pairs of the processing unit auxiliary signal adjustment, specially frequency domain is adjusted, institute
Stating method of adjustment is, exp is multiplied by the frequency-region signal of the subcarrier of the auxiliary signal（-j*2pi*K/Nc*T）, wherein, K is
The sub-carrier positions, the T is first time-domain signal in the position of time domain peak power.
Or, the method adjusted by time domain is according to order from left to right, according to first time-domain signal in time domain
The position T of peak power, cyclic shift T to the right is carried out to the time-domain signal of the auxiliary signal after inverse fast Fourier transform.
The embodiments of the invention provide the access device in a kind of WLAN, by poor free time of noise
Reference signal is sent in carrier wave and is used as auxiliary as auxiliary signal or in the case where not needing channel estimation using pilot signal
Signal, and when adjusting maximum in the phase of auxiliary signal, the modulated signal by the reverse maximum of auxiliary signal with needing transmission
The peak-to-average force ratio of signal is adjusted in domain Signal averaging, the method for neutralizing modulated signal time-domain power, reduction ofdm system, can be degraded
Computation complexity, improves signal transacting efficiency.
As shown in figure 3, the embodiment of the present invention additionally provides a kind of access device of WLAN, described device 30 can be with
It is that access point or handheld terminal etc. can include network interface using equipment in a wireless local area network, described device 30
31st, processor 32 and memory 33.System bus 34 is used to connect network interface 31, processor 32 and memory 33.
Network interface 31 is used for and external device communication.
Memory 33 can have software module in permanent memory, such as hard disk drive and flash memory, memory 33
And device driver.Software module is able to carry out the various functions module of the above method of the present invention；Device driver can be with
It is network and interface drive program.
On startup, these component softwares are loaded into memory 33, are then accessed and are performed as follows by processor 32
Instruction：
Step 1, inverse fast Fourier transform is carried out to the modulation frequency domain symbol signal for needing to send, obtains the first time domain letter
Number arrangement set；
Step 2, searched in the first time-domain signal sequence more than the time-domain signal of power threshold and time domain letter
Number time-domain position；
Step 3, frequency domain auxiliary signal is sent in the first subcarrier, the frequency domain auxiliary signal is adjusted, so that
The time-domain position power that the second time-domain signal after the frequency domain auxiliary signal time-frequency conversion is obtained in the first time-domain signal is maximum, side
To on the contrary, first time-domain signal is prominent time-domain signal in the time-domain signal；
Step 4, second time-domain signal of the auxiliary signal after adjustment is added with the first time-domain signal sequence,
To reduce the peak-to-average force ratio of the first time-domain signal sequence.
The embodiments of the invention provide a kind of device of reducing PAR of OFDM system, by signal to noise ratio
Reference signal is sent in poor idle sub-carrier as auxiliary signal or in the case where not needing channel estimation by pilot tone
Signal adjusts the phase of auxiliary signal as auxiliary signal, by the reverse maximum of auxiliary signal with needing the modulation of transmission
The peak of signal is adjusted in signal in maximum time-domain signal superposition, the method for neutralizing modulated signal time-domain power, reduction ofdm system
Compare, can degrade computation complexity, improve signal transacting efficiency.
Professional should further appreciate that, each example described with reference to the embodiments described herein
Unit and algorithm steps, can be realized with electronic hardware, computer software or the combination of the two, hard in order to clearly demonstrate
The interchangeability of part and software, generally describes the composition and step of each example according to function in the above description.
These functions are performed with hardware or software mode actually, depending on the application-specific and design constraint of technical scheme.
Professional and technical personnel can realize described function to each specific application using distinct methods, but this realize
It is not considered that beyond the scope of this invention.
The method that is described with reference to the embodiments described herein can use hardware, computing device the step of algorithm
Software module, or the two combination are implemented.Software module can be placed in random access memory（RAM）, internal memory, read-only storage
（ROM）, electrically programmable ROM, electrically erasable ROM, register, hard disk, moveable magnetic disc, CD-ROM or technical field
In any other form of storage medium well known to interior.
Above-described embodiment, has been carried out further to the purpose of the present invention, technical scheme and beneficial effect
Describe in detail, should be understood that the embodiment that the foregoing is only the present invention, be not intended to limit the present invention
Protection domain, within the spirit and principles of the invention, any modification, equivalent substitution and improvements done etc. all should be included
Within protection scope of the present invention.
Claims (14)
1. a kind of method of reducing PAR of OFDM system, it is characterised in that methods described includes：
Step 1, inverse fast Fourier transform is carried out to the frequency domain symbol signal for needing to send, obtains the first time-domain signal sequence；
Step 2, the time-domain signal and the time-domain signal more than power threshold are searched in the first time-domain signal sequence
Time-domain position；
Step 3, frequency domain auxiliary signal is sent in the first subcarrier, the frequency domain auxiliary signal is adjusted, to cause
The time-domain position power that the second time-domain signal after frequency domain auxiliary signal time-frequency conversion is stated in the first time-domain signal is maximum, direction phase
Instead, first time-domain signal is prominent time-domain signal in the time-domain signal；
Step 4, second time-domain signal of the frequency domain auxiliary signal after adjustment is added with the first time-domain signal sequence,
To reduce the peak-to-average force ratio of the first time-domain signal sequence；
Also include after the step 4：
Step 5, whether the peak-to-average force ratio after detection reduction meets setting thresholding, in the case where being unsatisfactory for setting thresholding, makes
With another frequency domain auxiliary signal, and step 3 is performed to step 5, until the peak-to-average force ratio meets setting thresholding or without available
Frequency domain auxiliary signal.
2. the method as described in claim 1, it is characterised in that the frequency domain auxiliary signal is pilot signal or carried in idle son
Sent on ripple be used for reduce the signal of peak-to-average force ratio.
3. the method as described in claim any one of 1-2, it is characterised in that in the step 3, to the frequency domain auxiliary signal
It is adjusted, including frequency domain adjustment, the method for adjustment is that the frequency-region signal of the subcarrier of the frequency domain auxiliary signal is multiplied by
Exp (- j*2pi*K/Nc*T), wherein, K is the sub-carrier positions, and Nc is total sub-carrier number, and the T is first time domain
Time-domain position of the signal in time domain peak power.
4. the method as described in claim any one of 1-2, it is characterised in that in the step 3, to the frequency domain auxiliary signal
It is adjusted, including time domain adjustment, the method for adjustment is, according to order from left to right, according to first time-domain signal
In time-domain position T, the corresponding time-domain signal of the frequency domain auxiliary signal after inverse fast Fourier transform is circulated to the right
Shift T.
5. the method as described in claim 1, it is characterised in that the time-domain signal more than power threshold is specially described
Prominent time-domain signal in one time domain signal sequence.
6. the method as described in claim 1, it is characterised in that the time-domain signal more than power threshold is specially described
The maximum time-domain signal of real part in one time domain signal sequence.
7. the method as described in claim 1, it is characterised in that the time-domain signal more than power threshold is specially described
The maximum time-domain signal of imaginary part in one time domain signal sequence.
8. the access device in a kind of WLAN, it is characterised in that the access device includes：
Converter unit, for carrying out inverse fast Fourier transform to the frequency domain symbol signal for needing to send, obtains the first time domain letter
Number sequence；
Searching unit, for being searched in the first time-domain signal sequence more than the time-domain signal of power threshold and time domain letter
Number time-domain position；
Processing unit, frequency domain auxiliary signal is sent in the first subcarrier, the frequency domain auxiliary signal is adjusted, to cause
The second time-domain signal after the frequency domain auxiliary signal time-frequency conversion is maximum in the time-domain position power of the first time-domain signal, direction
On the contrary, first time-domain signal is prominent time-domain signal in the time-domain signal；
Arithmetic element, to by second time-domain signal of the frequency domain auxiliary signal after adjustment and the first time-domain signal sequence
Row are added, to reduce the peak-to-average force ratio of the first time-domain signal sequence；
Also include execution unit, whether the peak-to-average force ratio after detection reduction meets setting thresholding, be unsatisfactory for setting thresholding
In the case of, control the processing unit and the arithmetic element to repeat, using another frequency domain auxiliary signal, until described
Peak-to-average force ratio meets setting thresholding or does not have available frequency domain auxiliary signal.
9. device as claimed in claim 8, it is characterised in that the frequency domain auxiliary signal is for pilot tone or in idle sub-carrier
Send be used for reduce the signal of peak-to-average force ratio.
10. the device as described in claim any one of 8-9, it is characterised in that the processing unit aids in the frequency domain believing
Number it is adjusted, including frequency domain adjustment, the method for adjustment is that the frequency-region signal of the subcarrier of the auxiliary signal is multiplied by
Exp (- j*2pi*K/Nc*T), wherein, K is the sub-carrier positions, and Nc is total sub-carrier number, and the T is first time domain
Signal is in the position of time domain peak power.
11. the device as described in claim any one of 8-9, it is characterised in that the processing unit aids in the frequency domain believing
Number it is adjusted, including frequency domain adjustment, the method for adjustment is, according to order from left to right, to be believed according to first time domain
Number time domain peak power position T, the time-domain signal of the auxiliary signal after inverse fast Fourier transform is circulated to the right
Shift T.
12. device as claimed in claim 8, it is characterised in that the time-domain signal more than power threshold is specially described
Prominent time-domain signal in first time-domain signal sequence.
13. device as claimed in claim 8, it is characterised in that the time-domain signal more than power threshold includes described the
The maximum time-domain signal of real part in one time domain signal sequence.
14. device as claimed in claim 8, it is characterised in that the time-domain signal more than power threshold includes described the
The maximum time-domain signal of imaginary part in one time domain signal sequence.
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| CN201310169155.3A CN104144140B (en) | 2013-05-09 | 2013-05-09 | The method and access device of a kind of reducing PAR of OFDM system |
| PCT/CN2013/088742 WO2014180128A1 (en) | 2013-05-09 | 2013-12-06 | Method and access device for reducing peak-to-average ratio in orthogonal frequency-division multiplexing system |
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| US10187239B2 (en) * | 2015-11-05 | 2019-01-22 | Huawei Technologies Co., Ltd. | Systems and methods to reduce the peak-to-average power ratio (PAPR) of signals in channel bonding |
| CN108282435B (en) * | 2017-01-06 | 2022-06-17 | 中兴通讯股份有限公司 | Signal transmission method and device |
| CN108183880B (en) * | 2018-01-09 | 2020-12-18 | 福建江夏学院 | OFDM peak-to-average power ratio suppressor based on amplitude limiting joint constellation expansion method |
| CN109905344B (en) * | 2019-03-25 | 2021-04-27 | 西安电子科技大学 | OFDM signal peak-to-average ratio suppression method based on partial transmission sequence |
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| CN101035105A (en) * | 2007-04-06 | 2007-09-12 | 西安电子科技大学 | Method and device for reserving the sub-carrier to reduce the peak average power ratio of the OFDM system based on IFFT/FFT |
| CN101202726A (en) * | 2006-12-14 | 2008-06-18 | 中兴通讯股份有限公司 | Method for reducing peak homo ratio in OFDM based on constellation expanding and vacant sub carrier wave |
| CN101414994A (en) * | 2008-10-16 | 2009-04-22 | 京信通信系统（中国）有限公司 | Method and apparatus for reducing peak average power ratio of multi-carrier system |
| CN101674279A (en) * | 2009-10-13 | 2010-03-17 | 广州杰赛科技股份有限公司 | Method for decreasing OFDM signal peak average rate |
| CN101771652A (en) * | 2009-12-31 | 2010-07-07 | 北京交通大学 | Amplitude limiting reserved sub carrier wave reduction PAPR method and system based on amplitude proportion factors |
| CN101778071A (en) * | 2010-01-29 | 2010-07-14 | 华中科技大学 | Method for reducing peak-to-average power ratio of OFDM signal |
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| GB2477986C (en) * | 2010-02-22 | 2013-12-25 | Toshiba Res Europ Ltd | Method and apparatus for crest factor reduction |
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| CN101202726A (en) * | 2006-12-14 | 2008-06-18 | 中兴通讯股份有限公司 | Method for reducing peak homo ratio in OFDM based on constellation expanding and vacant sub carrier wave |
| CN101035105A (en) * | 2007-04-06 | 2007-09-12 | 西安电子科技大学 | Method and device for reserving the sub-carrier to reduce the peak average power ratio of the OFDM system based on IFFT/FFT |
| CN101414994A (en) * | 2008-10-16 | 2009-04-22 | 京信通信系统（中国）有限公司 | Method and apparatus for reducing peak average power ratio of multi-carrier system |
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| CN101778071A (en) * | 2010-01-29 | 2010-07-14 | 华中科技大学 | Method for reducing peak-to-average power ratio of OFDM signal |
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