CN103873394A - Method and device for frequency offset estimation based on TDD special subframes - Google Patents

Abstract

The invention discloses a method and device for frequency offset estimation based on TDD special subframes. The method comprises that: an eNB extracts two inquiry reference signals for performing frequency offset estimation from last two sign bits in TDD special subframes transmitted from a user device, and performing frequency offset estimation on an uplink channel from the user device to the eNB according to the two inquiry reference signals. Compared with the prior art, the invention performs frequency offset estimation on the uplink channel from the user device to the eNB through the two last sign bits of the TDD special subframes and using the two inquiry signals used for performing the frequency offset estimation so that the frequency offset estimation can still be carried on when the uplink data transmission is absent. Furthermore, when the uplink data transmission is performing, the frequency offset estimation is performed by combining with the physical uplink channel demodulation reference signals so as to make the estimation of the PUCCH channel and the SRS channel more accurate.

Description

A kind of for carry out the method and apparatus of frequency deviation estimation based on TDD special subframe

Technical field

The present invention relates to communication technical field, relate in particular to a kind of for carry out the technology of frequency deviation estimation based on TDD special subframe.

Background technology

In wireless channel, there is time variation in wireless channel, wireless signal there will be frequency shift (FS) in transmitting procedure, for example Doppler frequency shift, or owing to having frequency departure between transmitter carrier frequency and receiver local oscillator, these all can make the orthogonality between subcarrier be destroyed, and cause the phase mutual interference between subchannel.

In the up processing of the LTE of physical layer, carrier frequency offset (Carrier FrequencyOffset, CFO) be physical uplink control channel (Physical Uplink ControlChannel, and inquire after the important parameter of reference signal (Sounding Reference Signal, SRS) PUCCH).In prior art, only in the time thering is uplink data transmission, calculate CFO, as according to physical uplink link sharing channel (Physical Uplink Shared Channel, PUSCH) demodulated reference signal (Demodulation Reference Signal, DMRS) is estimated CFO; In the time there is no uplink data transmission, conventionally use initial CFO assignment, rather than the CFO value of estimating.If CFO is not even as big as affecting signal, the channel estimating of PUCCH and SRS can not be affected by CFO.Otherwise, adopt initial CFO assignment to affect very large.

Therefore, in the time there is no uplink data transmission, especially, for pace of change and the unusual communication system of frequency sensitivity (frequency-sensitive), carrier frequency offset is estimated, in up channel processing, as being very important in PUCCH and SRS channel estimating.

Summary of the invention

The object of this invention is to provide a kind of for carry out the method and apparatus of frequency deviation estimation based on TDD special subframe.

According to an aspect of the present invention, provide a kind of in eNB for carry out the method for frequency deviation estimation based on TDD special subframe, wherein, the method comprises the following steps:

A, in latter two sign bit that is received from TDD special subframe that subscriber equipment sends, extracts for two of carrying out frequency deviation estimation and inquires after reference signal;

B inquires after reference signal according to described two, and described subscriber equipment to the up channel of eNB is carried out to frequency deviation estimation.

According to another aspect of the present invention, also provide a kind of in subscriber equipment for auxiliary method of carrying out frequency deviation estimation based on TDD special subframe, wherein, the method comprises the following steps:

A is received from the context configuring request that eNB sends;

B, according to described context configuring request, returns to the context configuration response corresponding with described context configuring request to described eNB;

C is according to described context configuring request, in latter two sign bit of TDD special subframe, sends for two of carrying out frequency deviation estimation and inquires after reference signal to described eNB;

Wherein, described context configuring request comprises following at least any one:

Described in-transmission, inquire after the cycle information of reference signal;

Described in-transmission, inquire after the time-domain position information of reference signal;

Described in-transmission, inquire after the frequency domain position information of reference signal.

According to a further aspect of the invention, also provide a kind of for carry out the eNB of frequency deviation estimation based on TDD special subframe, wherein, this eNB comprises:

Signal extracting device, for being received from latter two sign bit of TDD special subframe that subscriber equipment sends, extracting for two of carrying out frequency deviation estimation and inquires after reference signal;

Frequency deviation estimation device, for inquiring after reference signal according to described two, carries out frequency deviation estimation to described subscriber equipment to the up channel of eNB.

According to a further aspect of the invention, also provide a kind of for the auxiliary subscriber equipment that carries out frequency deviation estimation based on TDD special subframe, wherein, this subscriber equipment comprises:

Request receiving device, the context configuring request sending for being received from eNB;

Response return mechanism, for according to described context configuring request, returns to the context configuration response corresponding with described context configuring request to described eNB;

Sender unit, for according to described context configuring request, in latter two sign bit of TDD special subframe, sends for two of carrying out frequency deviation estimation and inquires after reference signal to described eNB;

Wherein, described context configuring request comprises following at least any one:

Described in-transmission, inquire after the cycle information of reference signal;

Described in-transmission, inquire after the time-domain position information of reference signal;

Described in-transmission, inquire after the frequency domain position information of reference signal.

According to a further aspect of the invention, also provide a kind of for carry out the system of frequency deviation estimation based on TDD special subframe, comprised eNB described above and subscriber equipment described above.

Compared with prior art, the present invention is by latter two sign bit of TDD special subframe, utilization is inquired after reference signal for two of carrying out frequency deviation estimation, subscriber equipment to the up channel of eNB is carried out to frequency deviation estimation, make in the time there is no uplink data transmission, still can carry out frequency deviation estimation, further, in the time having uplink data transmission, carry out frequency deviation estimation in conjunction with physics uplink shared channel demodulated reference signal, make PUCCH and SRS channel estimating more accurate.

Accompanying drawing explanation

By reading the detailed description that non-limiting example is done of doing with reference to the following drawings, it is more obvious that other features, objects and advantages of the present invention will become:

Fig. 1 illustrate according to one aspect of the invention for carry out the method flow diagram of frequency deviation estimation based on TDD special subframe;

Fig. 2 illustrates the schematic diagram that carries out frequency deviation estimation in prior art;

Fig. 3 illustrate in accordance with a preferred embodiment of the present invention for carry out the schematic diagram of frequency deviation estimation based on TDD special subframe;

Fig. 4 illustrate according to another preferred embodiment of the present invention for carry out the schematic flow sheet of frequency deviation estimation based on TDD special subframe;

Fig. 5 illustrate according to a further aspect of the present invention for carry out the equipment schematic diagram of frequency deviation estimation based on TDD special subframe.

In accompanying drawing, same or analogous Reference numeral represents same or analogous parts.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.

Fig. 1 illustrate according to a further aspect of the present invention for carry out the method flow diagram of frequency deviation estimation based on TDD special subframe.

In step S101, eNB, in latter two sign bit that is received from TDD special subframe that subscriber equipment sends, extracts for two of carrying out frequency deviation estimation and inquires after reference signal.Particularly, in the up processing of physical layer of LTE, carrier frequency offset (CFO) is physical uplink control channel (PUCCH) and the important parameter of inquiring after reference signal (SRS).In prior art, only in the time thering is uplink data transmission, calculate CFO, in the time there is no uplink data transmission, conventionally use initial CFO assignment, rather than CFO estimated value.For PUCCH and SRS are had to an accurate channel estimating, the present invention proposes a kind of by add the method for inquiring after reference signal and estimate CFO for carrying out two of frequency deviation estimation in TDD special subframe.Because this is periodically sent for the reference signal of inquiring after of carrying out frequency deviation estimation, and the processing of inquiring after reference signal is also uncomplicated, may there is time-domain resource and calculate CFO, therefore, can periodically utilize this to calculate CFO for the reference signal of inquiring after of carrying out frequency deviation estimation.In addition, in the time having uplink data transmission, can also calculate in conjunction with physics uplink shared channel demodulation reference signal the value of CFO, that is, carry out frequency deviation estimation.

For example, subscriber equipment is inquired after the cycle information, time-domain position information, frequency domain position information etc. of reference signal according to included transmission in the context configuring request receiving, in latter two sign bit of TDD special subframe, put into for two of carrying out frequency deviation estimation and inquired after reference signal, and this TDD special subframe is sent to eNB, this eNB is received from the TDD special subframe that subscriber equipment sends, and in latter two sign bit of this TDD special subframe, extract this and inquire after reference signal for two of carrying out frequency deviation estimation.

At this, in a radio frames, there are 10 wireless sub-frames, wherein, in these 10 wireless sub-frames, there is one or two special subframe, the length of this special subframe is consistent with the length of other wireless sub-frames, is a TTI, that is, and 1ms.

In step S102, eNB inquires after reference signal according to described two, and described subscriber equipment to the up channel of eNB is carried out to frequency deviation estimation.

Particularly, as shown in Figure 2, in prior art, in the time thering is uplink data transmission, estimate the value of CFO according to Physical Uplink Shared Channel demodulated reference signal,, carry out frequency deviation estimation, conventionally use the frequency pilot sign of adjacent time-slots in a subframe to carry out frequency deviation estimation.At this, in a time slot, there are 7 sign bits, respectively there are 3 data symbols front and back, and middle 1 is frequency pilot sign.

The signal that eNB receives is as follows:

${\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,z}^{\mathrm{pilot}}\&ap;\exp \left(2\mathrm{j\&pi;}\frac{N_s\&CenterDot;\mathrm{\&Delta;\&epsiv;}}{N_{\mathrm{FFT}}}\right){\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,a}^{\mathrm{pilot}},$

${\mathrm{\&gamma;}}_{\mathrm{LongTerm}}=E\left\{{\left({\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,z}^{\mathrm{pilot}}\right)}^{\mathrm{<figure-callout\; id="1"\; label="H\; H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}{H}_{}^{}{}_{1,a}^{\mathrm{pilot}}\right|\widehat{\mathrm{\&epsiv;}}\}\&ap;\exp \left(2\mathrm{j\&pi;}\frac{N_s\&CenterDot;\mathrm{\&Delta;\&epsiv;}}{N_{\mathrm{FFT}}}\right)E\{{\left|\right|{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,a}^{\mathrm{pilot}}\left|\right|}^2\left|\widehat{\mathrm{\&epsiv;}}\right\}$ Therefore, frequency deviation is estimated $\mathrm{\&Delta;\&epsiv;}=\frac{N_{\mathrm{FFT}}}{2\mathrm{\&pi;}{N}_s}\mathrm{angle}\left({\mathrm{\&gamma;}}_{\mathrm{LongTerm}}\right)=\frac{N_{\mathrm{FFT}}}{{2\mathrm{\&pi;N}}_s}\mathrm{angle}\left\{E{\left({\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,a}^{\mathrm{pilot}}\right)}^{\mathrm{<figure-callout\; id="1"\; label="H\; H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}{H}_{}^{}{}_{1,a}^{\mathrm{pilot}}\right|\widehat{\mathrm{\&epsiv;}}\}$

The frequency deviation region that this algorithm estimates is [Δ ε _max, Δ ε _max], wherein, ${\mathrm{\&Delta;\&epsiv;}}_{\max }=\&PlusMinus;2\mathrm{\&pi;}\frac{N_s\&CenterDot;\mathrm{\&Delta;}{\mathrm{\&epsiv;}}_{\max }}{N_{\mathrm{FFT}}}\&Element;[-\mathrm{\&pi;},\mathrm{\&pi;}],$ , ${\mathrm{\&Delta;\&epsiv;}}_{\max }=\frac{N_{\mathrm{FFT}}}{{2N}_s}=0.0667,$ Corresponding to ± 1000Hz.

As shown in Figure 3, in the present invention, in step S102, this eNB inquires after reference signal according to these two, and this subscriber equipment to the up channel of this eNB is carried out to frequency deviation estimation.This eNB carries out frequency deviation estimation by these two time domain conjugate multiplication of inquiring after reference signal, as adopted the algorithm that algorithm is identical as shown in Fig. 2 to carry out frequency deviation estimation, but what use is the reference signal of inquiring after in latter two sign bit of this TDD special subframe, rather than adopts Physical Uplink Shared Channel demodulated reference signal to carry out frequency deviation estimation.

At this, only need to revise ${\mathrm{\&Delta;\&epsiv;}}_{\max }=\frac{N_{\mathrm{FFT}}}{2{\hat{N}}_s}=0.4667.$

Certainly, also can adopt other CFO algorithm for estimating to carry out frequency deviation estimation at this, as by system emulation, for this eNB selects a kind of suitable CFO algorithm for estimating, as select a kind of CFO algorithm for estimating that reaches the balance between accuracy and complexity.Those skilled in the art will be understood that above-mentioned algorithm is only for giving an example, and other existing algorithms that maybe may occur, as applicable to the present invention, also should be included in protection range of the present invention, and are contained in this at this with way of reference.

In a preferred embodiment, this eNB sends context configuring request to described subscriber equipment; This subscriber equipment is received from the context configuring request that this eNB sends; According to described context configuring request, return to the context configuration response corresponding with described context configuring request to described eNB; This eNB is received from the context configuration response that described subscriber equipment returns, and wherein, described context configuration response is corresponding with described context configuring request; And then this subscriber equipment is according to this context configuring request, in latter two sign bit of TDD special subframe, sends for two of carrying out frequency deviation estimation and inquire after reference signal to described eNB; This eNB, in latter two sign bit that is received from TDD special subframe that subscriber equipment sends, extracts for two of carrying out frequency deviation estimation and inquires after reference signal; Inquire after reference signal according to described two, described subscriber equipment to the up channel of eNB is carried out to frequency deviation estimation; Wherein, described context configuring request comprises following at least any one:

Described in-transmission, inquire after the cycle information of reference signal;

Described in-transmission, inquire after the time-domain position information of reference signal;

Described in-transmission, inquire after the frequency domain position information of reference signal.

For example, as shown in Figure 4, base-band resource controller (Band ResourceController in eNB, BRC) send respectively context configuring request to subscriber equipment, physical layer function entity (Physical Layer) and ascending resource scheduling device (UL Scheduler), to notify these three entities to send the cycle information of inquiring after reference signal for carrying out frequency deviation estimation, time-domain position information, frequency domain position information etc.; This subscriber equipment, physical layer function entity and ascending resource scheduling device are respectively to this base-band resource controller feedback acknowledgment response; This base-band resource controller receives respectively the confirmation response that these three entities return; And then, this subscriber equipment is according to this context configuring request, according to transmission included in this request for carrying out the cycle information of inquiring after reference signal, time-domain position information, frequency domain position information etc. of frequency deviation estimation, in latter two sign bit of TDD special subframe, add this to inquire after reference signal for two of carrying out frequency deviation estimation, and this TDD special subframe is sent to this eNB.

At this, eNB sends context configuring request, indicates each subscriber equipment to send the cycle of inquiring after reference signal and the time-frequency position estimated for frequency deviation, and they are different from the common reference signal context configuring request of inquiring after.Sending this default value cycle of inquiring after reference signal of estimating for frequency deviation is for example 5ms or 10ms.In a radio frames, have 10 wireless sub-frames, wherein, in these 10 wireless sub-frames, have one or two special subframe, the length of this special subframe is consistent with the length of other wireless sub-frames, is a TTI, that is, and and 1ms.Should note only considering the special subframe configuration of UpPTS length more than two sign bits herein.

Preferably, the method also comprises step S103 (not shown), and in this step S103, eNB, in uplink shared channel, is received from the demodulated reference signal that described subscriber equipment sends; Subsequently, in step S102, eNB according to described in inquire after reference signal, and in conjunction with described demodulated reference signal, described subscriber equipment to the up channel of described eNB is carried out to frequency deviation estimation.

Particularly, cannot carry out frequency deviation estimation during owing to there is no uplink data transmission, adopt the reference signal of inquiring after for carrying out frequency deviation estimation periodically sending to estimate that CFO is a kind of important the supplementing to prior art.But because uplink data transmission is more frequent, the interval that CFO calculates is shorter, therefore, adopt the CFO of Physical Uplink Shared Channel demodulated reference signal calculating gained more accurate.Therefore,, in the time having uplink data transmission, eNB for carrying out the reference signal of inquiring after of frequency deviation estimation, and in conjunction with this demodulated reference signal, carries out frequency deviation estimation to this subscriber equipment to the up channel of this eNB according to these two.For example, in step S101, this eNB, in latter two sign bit that is received from TDD special subframe that subscriber equipment sends, extracts for two of carrying out frequency deviation estimation and inquires after reference signal; In step S103, this eNB, in uplink shared channel, is received from the demodulated reference signal that this subscriber equipment sends; Subsequently, in step S102, eNB for carrying out the reference signal of inquiring after of frequency deviation estimation, and in conjunction with this demodulated reference signal, carries out frequency deviation estimation to this subscriber equipment to the up channel of this eNB according to these two.

More preferably, in step S102, described in eNB basis, inquire after reference signal and described demodulated reference signal, and described in combination, inquire after the reference signal weights corresponding with described demodulated reference signal difference, described subscriber equipment to the up channel of described eNB is carried out to frequency deviation estimation.

Particularly, as previously mentioned, because uplink data transmission is more frequent, the interval that CFO calculates is shorter, therefore, adopts the CFO of Physical Uplink Shared Channel demodulated reference signal calculating gained more accurate.Therefore, when eNB inquires after reference signal and this demodulated reference signal and carries out frequency deviation while estimating in conjunction with this, can consider that this inquires after reference signal and the corresponding weights of this demodulated reference signal, as more frequent in sent due to Physical Uplink Shared Channel demodulated reference signal, amount of calculation is less, its weights these weights of inquiring after reference signal are larger.

Preferably, when described context configuring request is consistent with channel estimating configuring request, inquire after reference signal described in utilization, described subscriber equipment to the up channel of eNB is carried out to channel estimating.

Particularly, for carry out frequency deviation estimation inquire after reference signal and the common reference signal of inquiring after is all periodically sent by subscriber equipment.Its configuration information is all sent to subscriber equipment by eNB in context configuring request.But these two kinds are inquired after the object difference of reference signal.The former is for carrying out frequency deviation estimation, that is, CFO estimates, and the latter inquires after reference signal processing for conventional, as channel estimating etc.But, inquiring after reference signal when being all configured in identical time and time-frequency position and sending when these two kinds, they can be used to this two kinds of objects.,, in the time that this context configuring request is consistent with channel estimating configuring request, this eNB can utilize this for carrying out the reference signal of inquiring after of frequency deviation estimation, and this subscriber equipment to the up channel of this eNB is carried out to channel estimating.At this, for showing difference, the context configuring request for sending the common configuration information of inquiring after reference signal is called to channel estimating configuring request.

Fig. 4 illustrate according to a further aspect of the present invention for carry out the equipment schematic diagram of frequency deviation estimation based on TDD special subframe.This eNB comprises signal extracting device 501 and frequency deviation estimation device 502.

Signal extracting device 501 in this eNB, in latter two sign bit that is received from TDD special subframe that subscriber equipment sends, extracts for two of carrying out frequency deviation estimation and inquires after reference signal.Particularly, in the up processing of physical layer of LTE, carrier frequency offset (CFO) is physical uplink control channel (PUCCH) and the important parameter of inquiring after reference signal (SRS).In prior art, only in the time thering is uplink data transmission, calculate CFO, in the time there is no uplink data transmission, conventionally use initial CFO assignment, rather than CFO estimated value.For PUCCH and SRS are had to an accurate channel estimating, the present invention proposes a kind of by add the method for inquiring after reference signal and estimate CFO for carrying out two of frequency deviation estimation in TDD special subframe.Because this is periodically sent for the reference signal of inquiring after of carrying out frequency deviation estimation, and the processing of inquiring after reference signal is also uncomplicated, may there is time-domain resource and calculate CFO, therefore, can periodically utilize this to calculate CFO for the reference signal of inquiring after of carrying out frequency deviation estimation.In addition, in the time having uplink data transmission, can also calculate in conjunction with physics uplink shared channel demodulation reference signal the value of CFO, that is, carry out frequency deviation estimation.

For example, subscriber equipment is inquired after the cycle information, time-domain position information, frequency domain position information etc. of reference signal according to included transmission in the context configuring request receiving, in latter two sign bit of TDD special subframe, put into for two of carrying out frequency deviation estimation and inquired after reference signal, and this TDD special subframe is sent to eNB, this eNB is received from the TDD special subframe that subscriber equipment sends, and in latter two sign bit of this TDD special subframe, extract this and inquire after reference signal for two of carrying out frequency deviation estimation.

At this, in a radio frames, there are 10 wireless sub-frames, wherein, in these 10 wireless sub-frames, there is one or two special subframe, the length of this special subframe is consistent with the length of other wireless sub-frames, is a TTI, that is, and 1ms.

Subsequently, the frequency deviation estimation device 502 in this eNB is inquired after reference signal according to described two, and described subscriber equipment to the up channel of eNB is carried out to frequency deviation estimation.

Particularly, as shown in Figure 2, in prior art, in the time thering is uplink data transmission, estimate the value of CFO according to Physical Uplink Shared Channel demodulated reference signal,, carry out frequency deviation estimation, conventionally use the frequency pilot sign of adjacent time-slots in a subframe to carry out frequency deviation estimation.At this, in a time slot, there are 7 sign bits, respectively there are 3 data symbols front and back, and middle 1 is frequency pilot sign.

The signal that eNB receives is as follows:

${\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,z}^{\mathrm{pilot}}\&ap;\exp \left(2\mathrm{j\&pi;}\frac{N_s\&CenterDot;\mathrm{\&Delta;\&epsiv;}}{N_{\mathrm{FFT}}}\right){\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,a}^{\mathrm{pilot}},$

${\mathrm{\&gamma;}}_{\mathrm{LongTerm}}=E\left\{{\left({\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,z}^{\mathrm{pilot}}\right)}^{\mathrm{<figure-callout\; id="1"\; label="H\; H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}{H}_{}^{}{}_{1,a}^{\mathrm{pilot}}\right|\widehat{\mathrm{\&epsiv;}}\}\&ap;\exp \left(2\mathrm{j\&pi;}\frac{N_s\&CenterDot;\mathrm{\&Delta;\&epsiv;}}{N_{\mathrm{FFT}}}\right)E\{{\left|\right|{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,a}^{\mathrm{pilot}}\left|\right|}^2\left|\widehat{\mathrm{\&epsiv;}}\right\}$ Therefore, frequency deviation is estimated $\mathrm{\&Delta;\&epsiv;}=\frac{N_{\mathrm{FFT}}}{2\mathrm{\&pi;}{N}_s}\mathrm{angle}\left({\mathrm{\&gamma;}}_{\mathrm{LongTerm}}\right)=\frac{N_{\mathrm{FFT}}}{{2\mathrm{\&pi;N}}_s}\mathrm{angle}\left\{E{\left({\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,a}^{\mathrm{pilot}}\right)}^{\mathrm{<figure-callout\; id="1"\; label="H\; H"\; filenames="HDA00002581810600022.png"\; state="\{\{state\}\}">H</figure-callout>}}{H}_{}^{}{}_{1,a}^{\mathrm{pilot}}\right|\widehat{\mathrm{\&epsiv;}}\}$

The frequency deviation region that this algorithm estimates is [Δ ε _max, Δ ε _max], wherein, ${\mathrm{\&Delta;\&epsiv;}}_{\max }=\&PlusMinus;2\mathrm{\&pi;}\frac{N_s\&CenterDot;\mathrm{\&Delta;}{\mathrm{\&epsiv;}}_{\max }}{N_{\mathrm{FFT}}}\&Element;[-\mathrm{\&pi;},\mathrm{\&pi;}],$ , ${\mathrm{\&Delta;\&epsiv;}}_{\max }=\frac{N_{\mathrm{FFT}}}{{2N}_s}=0.0667,$ Corresponding to ± 1000Hz.

As shown in Figure 3, in the present invention, the frequency deviation estimation device 502 in this eNB is inquired after reference signal according to these two, and this subscriber equipment to the up channel of this eNB is carried out to frequency deviation estimation.This eNB carries out frequency deviation estimation by these two time domain conjugate multiplication of inquiring after reference signal, as adopted the algorithm that algorithm is identical as shown in Fig. 2 to carry out frequency deviation estimation, but what use is the reference signal of inquiring after in latter two sign bit of this TDD special subframe, rather than adopts Physical Uplink Shared Channel demodulated reference signal to carry out frequency deviation estimation.

At this, only need to revise ${\mathrm{\&Delta;\&epsiv;}}_{\max }=\frac{N_{\mathrm{FFT}}}{2{\hat{N}}_s}=0.4667.$

Certainly, also can adopt other CFO algorithm for estimating to carry out frequency deviation estimation at this, as by system emulation, for this eNB selects a kind of suitable CFO algorithm for estimating, as select a kind of CFO algorithm for estimating that reaches the balance between accuracy and complexity.Those skilled in the art will be understood that above-mentioned algorithm is only for giving an example, and other existing algorithms that maybe may occur, as applicable to the present invention, also should be included in protection range of the present invention, and are contained in this at this with way of reference.

In a preferred embodiment, this eNB also comprises send-request unit (not shown) and response receiving system (not shown); This subscriber equipment comprises request receiving device (not shown), response return mechanism (not shown) and sender unit (not shown).Send-request unit in this eNB sends context configuring request to described subscriber equipment; Request receiving device in this subscriber equipment is received from the context configuring request that this eNB sends; Response return mechanism in this subscriber equipment, according to described context configuring request, returns to the context configuration response corresponding with described context configuring request to described eNB; Response receiving system in this eNB is received from the context configuration response that described subscriber equipment returns, and wherein, described context configuration response is corresponding with described context configuring request; And then the sender unit in this subscriber equipment is according to this context configuring request, in latter two sign bit of TDD special subframe, sends for two of carrying out frequency deviation estimation and inquire after reference signal to described eNB; Signal extracting device 501 in this eNB, in latter two sign bit that is received from TDD special subframe that subscriber equipment sends, extracts for two of carrying out frequency deviation estimation and inquires after reference signal; Subsequently, the frequency deviation estimation device 502 in this eNB is inquired after reference signal according to described two, and described subscriber equipment to the up channel of eNB is carried out to frequency deviation estimation; Wherein, described context configuring request comprises following at least any one:

Described in-transmission, inquire after the cycle information of reference signal;

Described in-transmission, inquire after the time-domain position information of reference signal;

Described in-transmission, inquire after the frequency domain position information of reference signal.

For example, as shown in Figure 4, send-request unit in eNB, as base-band resource controller (Band Resource Controller, BRC) send respectively context configuring request to subscriber equipment, physical layer function entity (Physical Layer) and ascending resource scheduling device (ULScheduler), to notify these three entities to send the cycle information of inquiring after reference signal for carrying out frequency deviation estimation, time-domain position information, frequency domain position information etc.; This subscriber equipment (as, the response return mechanism on it), physical layer function entity and ascending resource scheduling device are respectively to this base-band resource controller feedback acknowledgment response; Response receiving system in this eNB, as base-band resource controller receives respectively this three confirmation that entity returned responses; And then, sender unit in this subscriber equipment is according to this context configuring request, according to transmission included in this request for carrying out the cycle information of inquiring after reference signal, time-domain position information, frequency domain position information etc. of frequency deviation estimation, in latter two sign bit of TDD special subframe, add this to inquire after reference signal for two of carrying out frequency deviation estimation, and this TDD special subframe is sent to this eNB.

At this, eNB sends context configuring request, indicates each subscriber equipment to send the cycle of inquiring after reference signal and the time-frequency position estimated for frequency deviation, and they are different from the common reference signal context configuring request of inquiring after.Sending this default value cycle of inquiring after reference signal of estimating for frequency deviation is for example 5ms or 10ms.In a radio frames, have 10 wireless sub-frames, wherein, in these 10 wireless sub-frames, have one or two special subframe, the length of this special subframe is consistent with the length of other wireless sub-frames, is a TTI, that is, and and 1ms.Should note only considering the special subframe configuration of UpPTS length more than two sign bits herein.

Preferably, this eNB also comprises signal receiving device (not shown), and the signal receiving device in this eNB, in uplink shared channel, is received from the demodulated reference signal that described subscriber equipment sends; Subsequently, frequency deviation estimation device in this eNB 502 according to described in inquire after reference signal, and in conjunction with described demodulated reference signal, described subscriber equipment to the up channel of described eNB is carried out to frequency deviation estimation.

Particularly, cannot carry out frequency deviation estimation during owing to there is no uplink data transmission, adopt the reference signal of inquiring after for carrying out frequency deviation estimation periodically sending to estimate that CFO is a kind of important the supplementing to prior art.But because uplink data transmission is more frequent, the interval that CFO calculates is shorter, therefore, adopt the CFO of Physical Uplink Shared Channel demodulated reference signal calculating gained more accurate.Therefore,, in the time having uplink data transmission, eNB for carrying out the reference signal of inquiring after of frequency deviation estimation, and in conjunction with this demodulated reference signal, carries out frequency deviation estimation to this subscriber equipment to the up channel of this eNB according to these two.For example, the signal extracting device 501 in this eNB, in latter two sign bit that is received from TDD special subframe that subscriber equipment sends, extracts for two of carrying out frequency deviation estimation and inquires after reference signal; Subsequently, the signal receiving device in this eNB, in uplink shared channel, is received from the demodulated reference signal that this subscriber equipment sends; Subsequently, the frequency deviation estimation device 502 in this eNB for carrying out the reference signal of inquiring after of frequency deviation estimation, and in conjunction with this demodulated reference signal, carries out frequency deviation estimation to this subscriber equipment to the up channel of this eNB according to these two.

More preferably, described in frequency deviation estimation device 502 bases in this eNB, inquire after reference signal and described demodulated reference signal, and described in combination, inquire after the reference signal weights corresponding with described demodulated reference signal difference, described subscriber equipment to the up channel of described eNB is carried out to frequency deviation estimation.

Particularly, as previously mentioned, because uplink data transmission is more frequent, the interval that CFO calculates is shorter, therefore, adopts the CFO of Physical Uplink Shared Channel demodulated reference signal calculating gained more accurate.Therefore, when eNB inquires after reference signal and this demodulated reference signal and carries out frequency deviation while estimating in conjunction with this, can consider that this inquires after reference signal and the corresponding weights of this demodulated reference signal, as more frequent in sent due to Physical Uplink Shared Channel demodulated reference signal, amount of calculation is less, its weights these weights of inquiring after reference signal are larger.

Preferably, this eNB also comprises channel estimating apparatus (not shown), channel estimating apparatus in this eNB when described context configuring request consistent with channel estimating configuring request, inquire after reference signal described in utilization, described subscriber equipment to the up channel of eNB is carried out to channel estimating.

Particularly, for carry out frequency deviation estimation inquire after reference signal and the common reference signal of inquiring after is all periodically sent by subscriber equipment.Its configuration information is all sent to subscriber equipment by eNB in context configuring request.But these two kinds are inquired after the object difference of reference signal.The former is for carrying out frequency deviation estimation, that is, CFO estimates, and the latter inquires after reference signal processing for conventional, as channel estimating etc.But, inquiring after reference signal when being all configured in identical time and time-frequency position and sending when these two kinds, they can be used to this two kinds of objects.,, in the time that this context configuring request is consistent with channel estimating configuring request, the channel estimating apparatus in this eNB can utilize this for carrying out the reference signal of inquiring after of frequency deviation estimation, and this subscriber equipment to the up channel of this eNB is carried out to channel estimating.At this, for showing difference, the context configuring request for sending the common configuration information of inquiring after reference signal is called to channel estimating configuring request.

It should be noted that the present invention can be implemented in the assembly of software and/or software and hardware, for example, can adopt application-specific integrated circuit (ASIC) (ASIC), general object computer or any other similar hardware device to realize.In one embodiment, software program of the present invention can carry out to realize step mentioned above or function by processor.Similarly, software program of the present invention (comprising relevant data structure) can be stored in computer readable recording medium storing program for performing, for example, and RAM memory, magnetic or CD-ROM driver or floppy disc and similar devices.In addition, steps more of the present invention or function can adopt hardware to realize, for example, thereby as coordinate the circuit of carrying out each step or function with processor.

In addition, a part of the present invention can be applied to computer program, and for example computer program instructions, in the time that it is carried out by computer, by the operation of this computer, can call or provide the method according to this invention and/or technical scheme.And call the program command of method of the present invention, may be stored in fixing or movably in recording medium, and/or be transmitted by the data flow in broadcast or other signal bearing medias, and/or be stored in according in the working storage of the computer equipment of described program command operation.At this, comprise according to one embodiment of present invention a device, this device comprises memory for storing computer program instructions and the processor for execution of program instructions, wherein, in the time that this computer program instructions is carried out by this processor, trigger this device and move based on aforementioned according to the method for multiple embodiment of the present invention and/or technical scheme.

To those skilled in the art, obviously the invention is not restricted to the details of above-mentioned one exemplary embodiment, and in the situation that not deviating from spirit of the present invention or essential characteristic, can realize the present invention with other concrete form.Therefore, no matter from which point, all should regard embodiment as exemplary, and be nonrestrictive, scope of the present invention is limited by claims rather than above-mentioned explanation, is therefore intended to all changes that drop in the implication and the scope that are equal to important document of claim to be included in the present invention.Any Reference numeral in claim should be considered as limiting related claim.In addition, obviously other unit or step do not got rid of in " comprising " word, and odd number is not got rid of plural number.Multiple unit of stating in device claim or device also can be realized by software or hardware by a unit or device.The first, the second word such as grade is used for representing title, and does not represent any specific order.

Claims (13)

1. In eNB for carry out a method for frequency deviation estimation based on TDD special subframe, wherein, the method comprises the following steps:

   A, in latter two sign bit that is received from TDD special subframe that subscriber equipment sends, extracts for two of carrying out frequency deviation estimation and inquires after reference signal;

   B inquires after reference signal according to described two, and described subscriber equipment to the up channel of eNB is carried out to frequency deviation estimation.
2. 2. method according to claim 1, wherein, the method also comprises:

   -in uplink shared channel, be received from the demodulated reference signal that described subscriber equipment sends;

   Wherein, described step b comprises:

   Described in-basis, inquire after reference signal, and in conjunction with described demodulated reference signal, described subscriber equipment to the up channel of described eNB is carried out to frequency deviation estimation.
3. 3. method according to claim 2, wherein, described step b comprises:

   Described in-basis, inquire after reference signal and described demodulated reference signal, and described in combination, inquire after the reference signal weights corresponding with described demodulated reference signal difference, described subscriber equipment to the up channel of described eNB is carried out to frequency deviation estimation.
4. 4. according to the method in any one of claims 1 to 3, wherein, the method also comprises:

   -send context configuring request to described subscriber equipment;

   -be received from the context configuration response that described subscriber equipment returns, wherein, described context configuration response is corresponding with described context configuring request;

   Wherein, described context configuring request comprises following at least any one:

   Described in-transmission, inquire after the cycle information of reference signal;

   Described in-transmission, inquire after the time-domain position information of reference signal;

   Described in-transmission, inquire after the frequency domain position information of reference signal.
5. 5. method according to claim 4, wherein, the method also comprises:

   -when described context configuring request is consistent with channel estimating configuring request, inquire after reference signal described in utilization, described subscriber equipment to the up channel of eNB is carried out to channel estimating.
6. In subscriber equipment for an auxiliary method of carrying out frequency deviation estimation based on TDD special subframe, wherein, the method comprises the following steps:

   A is received from the context configuring request that eNB sends;

   B, according to described context configuring request, returns to the context configuration response corresponding with described context configuring request to described eNB;

   C is according to described context configuring request, in latter two sign bit of TDD special subframe, sends for two of carrying out frequency deviation estimation and inquires after reference signal to described eNB;

   Wherein, described context configuring request comprises following at least any one:

   Described in-transmission, inquire after the cycle information of reference signal;

   Described in-transmission, inquire after the time-domain position information of reference signal;

   Described in-transmission, inquire after the frequency domain position information of reference signal.
7. 7. for carry out an eNB for frequency deviation estimation based on TDD special subframe, wherein, this eNB comprises:

   Signal extracting device, for being received from latter two sign bit of TDD special subframe that subscriber equipment sends, extracting for two of carrying out frequency deviation estimation and inquires after reference signal;

   Frequency deviation estimation device, for inquiring after reference signal according to described two, carries out frequency deviation estimation to described subscriber equipment to the up channel of eNB.
8. 8. eNB according to claim 7, wherein, this eNB also comprises:

   Signal receiving device, at uplink shared channel, is received from the demodulated reference signal that described subscriber equipment sends;

   Wherein, described frequency deviation estimation device is used for:

   Described in-basis, inquire after reference signal, and in conjunction with described demodulated reference signal, described subscriber equipment to the up channel of described eNB is carried out to frequency deviation estimation.
9. 9. eNB according to claim 8, wherein, described frequency deviation estimation device is used for:

   Described in-basis, inquire after reference signal and described demodulated reference signal, and described in combination, inquire after the reference signal weights corresponding with described demodulated reference signal difference, described subscriber equipment to the up channel of described eNB is carried out to frequency deviation estimation.
10. 10. according to the eNB described in any one in claim 7 to 9, wherein, this eNB also comprises:

    Send-request unit, for sending context configuring request to described subscriber equipment;

    Response receiving system, the context configuration response of returning for being received from described subscriber equipment, wherein, described context configuration response is corresponding with described context configuring request;

    Wherein, described context configuring request comprises following at least any one:

    Described in-transmission, inquire after the cycle information of reference signal;

    Described in-transmission, inquire after the time-domain position information of reference signal;

    Described in-transmission, inquire after the frequency domain position information of reference signal.
11. 11. eNB according to claim 10, wherein, this eNB also comprises:

    Channel estimating apparatus, for when described context configuring request consistent with channel estimating configuring request, inquire after reference signal described in utilization, described subscriber equipment to the up channel of eNB is carried out to channel estimating.
12. 12. 1 kinds for the auxiliary subscriber equipment that carries out frequency deviation estimation based on TDD special subframe, and wherein, this subscriber equipment comprises:

    Request receiving device, the context configuring request sending for being received from eNB;

    Response return mechanism, for according to described context configuring request, returns to the context configuration response corresponding with described context configuring request to described eNB;

    Sender unit, for according to described context configuring request, in latter two sign bit of TDD special subframe, sends for two of carrying out frequency deviation estimation and inquires after reference signal to described eNB;

    Wherein, described context configuring request comprises following at least any one:

    Described in-transmission, inquire after the cycle information of reference signal;

    Described in-transmission, inquire after the time-domain position information of reference signal;

    Described in-transmission, inquire after the frequency domain position information of reference signal.
13. 13. 1 kinds for carrying out the system of frequency deviation estimation based on TDD special subframe, comprise eNB and subscriber equipment as claimed in claim 12 as described in any one in claim 7 to 11.

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