CN101335986B - Method, network equipment and user equipment for random access - Google Patents
Method, network equipment and user equipment for random access Download PDFInfo
- Publication number
- CN101335986B CN101335986B CN2007101275196A CN200710127519A CN101335986B CN 101335986 B CN101335986 B CN 101335986B CN 2007101275196 A CN2007101275196 A CN 2007101275196A CN 200710127519 A CN200710127519 A CN 200710127519A CN 101335986 B CN101335986 B CN 101335986B
- Authority
- CN
- China
- Prior art keywords
- channel
- random access
- subchannel
- access code
- information
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The invention discloses a random access method, a network device and user equipment. The random access method comprises: dividing a random access channel into a plurality of sub-channels; based on reciprocity of an up channel and a down channel, analyzing channel quality of the random access sub-channel according to the information of the down channel; selecting the up channel and the down channel according to the channel quality of the plurality of sub-channels; adopting the obtained up sub-channel to transmit the random access code. The invention can increase detecting success ratio of the random access code, advance random access efficiency.
Description
Technical field
The present invention relates to the communications field, particularly relate to the method, the network equipment and the subscriber equipment that insert at random.
Background technology
In mobile communication system such as UMTS, 3GPP LTE and WiMAX, the terminal use inserts (Random Access) process at random and initially inserts wireless access network, and carries out the ascending resource scheduling request.
At time division duplex (Time Division Duplex, TDD) in the access process at random of system, need utilize Random Access Channel (RACH) to realize subscriber equipment (User Equipment, UE) uplink synchronous, process is as follows: UE at first sends targeting sequencing (the random access sequence sign indicating number is also referred to as sequence code) on the specific RACH based on competition; (Base Station BS) after the random access sequence sign indicating number that successfully detects the UE transmission, estimates the time delays that this random access sequence sign indicating number arrives in the base station; The sequential lead is fed back to terminal; Terminal is adjusted transmitting time to finish the uplink synchronous of UE according to this sequential lead.
Function for having realized that RACH random access sequence sign indicating number is born has following requirement to it: guarantee detection probability under low signal-to-noise ratio; Peak-to-average power ratio (Peak-to-Average Power Ratio, PAPR) low to improve up power amplification efficiency; Good automatic correlative property guarantees synchronization accuracy; Good cross correlation property guarantees that the interference between the different user is little; Abundant number guarantees access capability; Lower operand guarantees that the RACH response is fast.
A kind of in the prior art that 3GPP LTE system inserts at random, UE is picked at random access code in the burst (RACH Burst) of 1ms for the 1.25MHz duration in fixing bandwidth, constitute code division multiplexing (Code Division Multiplex, RACH mode CDM).For guaranteeing that sending sequence has lower PAPR, the LTE system has selected the Zadaoff-Chu sequence for use.Fig. 1 has provided the structure of RACH random access sequence sign indicating number among the LTE.
In the structure shown in Figure 1, the duration T of whole random access sequence sign indicating number
PRE=0.8ms, the Cyclic Prefix duration T
CP=0.1ms, the shared bandwidth of random access sequence sign indicating number (RACH random access sequence sign indicating number) is BW
RA=1.080MHz, corresponding 864 subcarriers that are spaced apart 1.25KHz.
In carrying out the invention process, the inventor finds to have following problem at least in the above-mentioned existing technology that inserts at random: the difficulty that detects the random access sequence sign indicating number in multidiameter fading channel condition lower network side is big, influences the realization of uplink synchronous.
Reason is: according to above-mentioned prior art access technology at random, in realization row synchronously before because UE does not have uplink synchronous, BS can't utilize ascending pilot frequency to carry out channel estimating.Therefore, for the RACH structure of above LTE, be to adopt the mode of accidental channel to upload.Upload the coherence bandwidth (471KHz) of the shared bandwidth of random access sequence sign indicating number (1.08MHz) owing to adopt accidental channel much larger than frequency-selective channel (TU), cause the up channel decline serious, therefore can to the detection of random access sequence sign indicating number exceptional hardship appear at network side, cause the signal that do not receive signal or receive poor quality probably, such as identifying the random access sequence sign indicating number; In addition, RACH is a up channel, therefore transmitting power is subjected to the restriction of UE, again because RACH is a channel based on competition, in same time slot, may have nonsynchronous random access sequence coded signal that a plurality of different users send, therefore exist between the user and disturb, cause BS can't identify the random access sequence sign indicating number.In the practice, at the detection of random access sequence sign indicating number, 10
-2Under the condition of false dismissal probability, (Additive White Gaussian Noise, AWGN) the omission performance under the channel condition has differed 10dB than additive white Gaussian noise through the omission performance behind the TU multidiameter fading channel.If can't identify the random access sequence sign indicating number, then BS can't calculate time delays according to the random access sequence yardage, also just can't realize uplink synchronous.
Simultaneously, the inventor also finds: reach 863 ZC sequences owing to having adopted in the said system, caused the increase of computation complexity.
Summary of the invention
The technical problem that embodiment of the present invention will solve provides a kind of method, the network equipment and subscriber equipment that inserts at random, can improve the success rate that random access code detects, and improves the efficient that inserts at random.
A kind of method that inserts at random is provided, comprises: Random Access Channel is divided into the plurality of sub channel; According to the reciprocity of up-downgoing channel, according to the channel quality of the described Random Access Channel subchannel of the information analysis of described down channel; Select up subchannel according to the channel quality of described plurality of sub channel; The up subchannel that adopts described selection to obtain sends random access code.
A kind of method that inserts at random is provided, comprises: receive the information of utilizing the Random Access Channel subchannel to send; Judge in the described information that receives and whether comprise random access code; When in the described information that receives, comprising random access code, obtain the round trip time delay RTD of subscriber equipment according to described random access code; Issue described RTD to described subscriber equipment.
A kind of subscriber equipment is provided, comprises channel cutting unit, channel quality analysis unit, channel selected cell and transmitting element, described channel cutting unit is used for Random Access Channel is divided into the plurality of sub channel; Described channel quality analysis unit is used for the reciprocity according to the up-downgoing channel, cuts apart the channel quality of the subchannel that obtains according to the described channel cutting unit of the information analysis of described down channel; Described channel selected cell is used for selecting up subchannel according to the described plurality of sub quality of channel that described channel quality analysis unit draws; The up subchannel that described transmitting element is used to adopt described channel selected cell to select to obtain sends random access code.
A kind of network equipment is provided, comprises receiving element, judging unit, time delay acquiring unit and issue the unit, described receiving element is used to receive the information of utilizing the Random Access Channel subchannel to send; Described judging unit is used for judging whether the information that described receiving element receives comprises random access code; Described time delay acquiring unit is used for when the information that described judgment unit judges goes out to receive comprises random access code, obtains the RTD of subscriber equipment according to described random access code; The described unit that issues is used to issue the RTD of described time delay acquiring unit acquisition to described subscriber equipment.
Above technical scheme as can be seen, because changing prior art, present embodiment adopt accidental channel to upload the mode of random access code, but at first Random Access Channel is divided into the plurality of sub channel, reduce the channel fading problem that upstream bandwidth causes greater than correlation bandwidth, next is according to the channel quality of the described Random Access Channel subchannel of the information analysis of down channel, select up subchannel to send described random access code according to channel quality, obviously improve the success rate that recipient's random access code detects, and then improve the efficient that inserts at random, avoid prior art because channel fading causes the recipient to be difficult to detect the technological deficiency of described random access code.
Description of drawings
Fig. 1 is the structure chart of prior art random access code;
Fig. 2 is the flow chart of accidental access method the 3rd execution mode of the present invention;
Fig. 3 is the schematic diagram that steps A is cut apart up channel among Fig. 2;
Fig. 4 is the structure chart of the random access code that step D sends among Fig. 2;
Fig. 5 is the flow chart that sends random sequence sign indicating number stage concrete grammar in the accidental access method execution mode of the present invention;
Fig. 6 is the flow chart that receives random sequence sign indicating number stage concrete grammar in the accidental access method execution mode of the present invention;
Fig. 7 is that step F is carried out the flow chart that peak value detects concrete grammar among Fig. 2;
Fig. 8 adopts the resulting random access code of accidental access method execution mode of the present invention to be detected as the comparison diagram of power and prior art;
Fig. 9 is the theory diagram of subscriber equipment first execution mode of the present invention;
Figure 10 is the theory diagram of the network equipment first execution mode of the present invention.
Embodiment
The detection performance that embodiment of the present invention is primarily aimed at random access code random access sequence sign indicating number in the existing wireless communications system is subjected to multipath fading to influence serious technical problem, and the high technical problem of receiving algorithm computation complexity, propose a kind of accidental access method, the network equipment and subscriber equipment, can be applied to such as in the TDD system.
The invention provides accidental access method first execution mode, may further comprise the steps:
Steps A: Random Access Channel is divided into the plurality of sub channel;
Step B: according to the reciprocity of up-downgoing channel, according to the channel quality of the described Random Access Channel subchannel of the information analysis of described down channel;
Step C: select up subchannel according to the channel quality of described plurality of sub channel;
Step D: the up subchannel that adopts described selection to obtain sends random access code.
In the above execution mode, changing prior art adopts accidental channel to upload the mode of random access code, but at first Random Access Channel is divided into the plurality of sub channel, carry out frequency division (FDM), reduce the channel fading problem that upstream bandwidth causes greater than correlation bandwidth, next is according to the channel quality of the described Random Access Channel subchannel of the information analysis of down channel, select up subchannel to send described random access code according to quality, promptly select up subchannel according to channel quality selectively, obviously improve the success rate that recipient's random access code detects, and then improve the efficient that inserts at random, avoid prior art to be difficult to detect the technological deficiency of described random access code owing to channel fading causes the recipient.
By to the analysis of random access code receptivity as can be known, signal energy and wireless channel situation are to influence the random access sequence sign indicating number to detect performance two big key factors, along with the increase (Ep/N of symbol emitted energy
0Rise), the false dismissal probability of random access sequence sign indicating number descends.Along with the deterioration (becoming the TU channel from AWGN) of channel conditions, the false dismissal probability of random access sequence sign indicating number rises.In embodiment of the present invention, be by the channel that sends the random access sequence sign indicating number being carried out preferable methods, promoting the detection performance of random access sequence sign indicating number.
When embodiment of the present invention is applied in the TDD system, be that hypothesis is before inserting at random, subscriber equipment has obtained down-going synchronous with the base station by descending synchronizing channel (SCH), and therefore by SCH or descending pilot frequency, subscriber equipment can obtain the information of down channel.Because the up-downgoing channel of TDD system adopts same frequency, the decline situation of up-downgoing channel can be regarded as identical, similar or corresponding, so the up-downgoing channel has reciprocity.The user that while moves for middle low speed, in the quite a long time, violent variation can not take place in its channel condition.Therefore present embodiment can obtain the information of each up subchannel by the information of down channel.Certainly, in the more execution modes of the present invention, the up-downgoing channel can adopt roughly the same frequency, also can adopt visibly different frequency; In the described reciprocity method of utilizing the up-downgoing channel, also can be not limited to utilize the decline situation of down channel to assess the decline situation of up subchannel, as long as can utilize the reciprocity of up-downgoing interchannel to assess the channel information of each up subchannel.
In addition,, need to receive the described random access code of uploading,, may further comprise the steps so the invention provides accidental access method second execution mode the recipient:
Step e: receive the information of utilizing the Random Access Channel subchannel to send;
Step F: judge in the described information that receives whether comprise random access code;
Step G: when in the described information that receives, comprising random access code, according to described random access code obtain subscriber equipment the round trip time delay (Round-trip Time Delay, RTD);
Step H: issue described RTD to described subscriber equipment, carry out uplink synchronous.
Above-mentioned execution mode is the method for the random access code of network side to receive user equipment transmission, because a plurality of subchannels of cutting apart in first execution mode send information, be not that each subchannel all can send random access code, therefore after network side receives the information of utilizing the transmission of Random Access Channel subchannel, need to judge from the information that up subchannel is uploaded, whether to comprise random access code, if comprise, then utilize this random access code to obtain the RTD of subscriber equipment, be handed down to subscriber equipment to adjust transmitting time, realize uplink synchronous.
Owing to introduced the prior information of up channel at the transmitting terminal of random access sequence sign indicating number, adopt frequency division FDM, sign indicating number to divide (CDM) dual mode to distinguish the user jointly simultaneously, also can adopt time-division, sign indicating number to divide a dual mode to distinguish the user jointly simultaneously, therefore this RA method be referred to as the to take a message sign indicating number frequency division of perception inserts (Channel Aware Code and Frequency DivisionMultiplex Random Access) at random in embodiment of the present invention.
For make purpose of the present invention, technical scheme, and advantage clearer, below with reference to the accompanying drawing execution mode that develops simultaneously, the present invention is described in more detail.
Consult Fig. 2, the invention provides accidental access method the 3rd execution mode, may further comprise the steps:
Steps A: Random Access Channel is divided into the plurality of sub channel;
At first, detect Effect on Performance for the random access sequence sign indicating number, the available bandwidth of whole RACH Burst is divided into the experimental process channel according to certain criterion (for example coherence bandwidth) for reducing frequency selective fading.
The coherence bandwidth of considering the TU channel is 471KHz, the RACH subchannel that the 1.08MHz total bandwidth of up channel can be divided into 4 bandwidth be 270KHz, and the subchannel bandwidth after cutting apart is the coherence bandwidth of 471KHz less than bandwidth.Wherein, the subchannel after each is cut apart is minimum to comprise 216 subcarriers, shows as Fig. 3.
Here, the shared frequency of described Random Access Channel is corresponding to the frequency band in the down channel.
Step B: according to the reciprocity of up-downgoing channel, according to the channel quality of the described Random Access Channel subchannel of the information analysis of described down channel;
Obtain the channel quality of described Random Access Channel subchannel according to the reciprocity of pilot tone in the described down channel and TDD channel, can adopt following method:
Analyze the decline situation of each several part channel in the described down channel, draw channel quality respectively with the described corresponding Random Access Channel subchannel of the decline negative correlation of described down channel each several part channel.
That is to say that if certain local channel fading ratio is more in the described down channel, then assessment draws the conclusion of its bad channel quality of Random Access Channel subchannel of corresponding this part down channel; If the channel fading of described down channel is fewer, then assessment draws the good conclusion of its channel quality of Random Access Channel subchannel of corresponding this part down channel.The result of described Random Access Channel subchannel assessment is as the basis of the up channel of selecting the described random access code of transmission.
Such as, down channel comprises frequency band 1,2,3, then Random Access Channel may be partitioned into 1,2,3 totally 3 subchannels (can certainly be divided into 2,4,5 subchannels etc.) accordingly, wherein the subchannel 1 of Random Access Channel is corresponding to the frequency band 1 of down channel, subchannel 2 is corresponding to frequency band 2, and subchannel 3 is corresponding to frequency band 3.If frequency band 2 declines that the subscriber equipment analysis draws in the described down channel are little, and frequency band 1,3 declines are bigger, it is good then can to assess subchannel 2 quality that draw Random Access Channel, and the subchannel 1,3 of Random Access Channel is of poor quality, i.e. the Random Access Channel subchannel quality that assessment draws and the decline situation of down channel frequency band are negative correlativing relation.
Step C: select up subchannel according to the channel quality of described plurality of sub channel;
UE according to the information (for example up subchannel frequency domain amplitude of fading etc.) of up channel, need choose the good RACH subchannel of performance before sending the random access sequence sign indicating number, then transmission random sequence sign indicating number on this subchannel.Different users can be distinguished with sequence (comprising cyclic shift) according to the subchannel that detects random access sequence sign indicating number place in the base station.
Select the method for up subchannel to include but not limited to:
When the channel quality that draws with the described Random Access Channel subchannel of the channel fading negative correlation of described down channel, select the Random Access Channel subchannel corresponding as up subchannel with the little down channel local channel of channel fading.
Said method can also be explained like this: in drawing described down channel during the channel quality of the positively related described Random Access Channel subchannel of channel magnitude, select the high described Random Access Channel subchannel of the channel magnitude of described down channel as up subchannel.
In the above-mentioned method of selecting up subchannel according to channel magnitude in the down channel, because the bandwidth 270KHz of RACH subchannel is less than the bandwidth 471KHz of coherence bandwidth, the frequency domain impulse response of channel can be similar to regards flat decline as.In this case, influencing network side is the amplitude of channel to the principal element of the performance of random access sequence sign indicating number identification.Can use of the measurement of following statistic at this as the channel magnitude characteristic.
In the formula, H (k) is the frequency domain impulse response of down channel.UL
iBe the initial subcarrier sequence number of i subchannel, M is a subcarrier number that the RACH subchannel is comprised.
For improving the energy efficiency that the random access sequence sign indicating number sends, UE selects in the down channel
That maximum subchannel is as transmit subchannel.The sequence number I that promptly sends subchannel satisfies following relation.
For guaranteeing that the random access sequence sign indicating number has desirable circulation auto-correlation and constant Cyclic Cross-Correlation Transform, guarantee to transmit simultaneously can use the Zadaoff-Chu sequence of length on each RACH subchannel by lower PAPR as M=211, be defined as follows formula.Always have the ZC sequence of 210 different roots.
n＝0，…，M-1
v＝1，…，M
Step D: the up subchannel that adopts described selection to obtain sends random access code.
Consult Fig. 4, the up subchannel that adopts described selection to obtain, and adopt first ascending time slot behind the up-downgoing transfer point to send random access code.
Consult Fig. 5, in an embodiment, the method that sends random access code can comprise:
D1, the RACH sequence is gone here and there and change;
D2, parallel RACH sequence is carried out discrete Fourier transform (DFT), and (Discrete Fourier Transform DFT) transforms on the frequency domain;
D3, according to the downlink information that obtains, select to send the used up RACH subchannel of random access sequence sign indicating number;
D4, use fast adverse Fourier transform (Inverse Fast Fourier Transform, IFFT) with frequency domain RACH sequence modulation to the subcarrier of corresponding RACH subchannel;
D5, the sample that will finish after the OFDM modulation carry out parallel serial conversion;
D6, before the OFDM symbol, insert Cyclic Prefix.
In order to guarantee the accuracy of uplink channel estimation, make RACH channel last symbol (comprising up-downgoing translation and protection time slot) followed by down channel.
More than describe as can be known, adopts accidental access method of the present invention in the step in up stage, can send the various uplink informations that comprise the random access sequence sign indicating number with the measured channel of matter, raising is in the signal uplink quality of accidental access stage.
Below continue to describe accidental access method execution mode of the present invention receives the stage at network side step:
Step e: receive the information of utilizing the Random Access Channel subchannel to send;
Consult Fig. 6, the reception testing process of random access sequence sign indicating number can comprise:
E1, will carry out mould/number (A/D) conversion by the signal that antenna receives;
E2, remove the Cyclic Prefix before the random access sequence sign indicating number, and go here and there and change;
E3, (Fast Fourier Transform FFT) carries out the OFDM demodulation to the time-domain signal that receives to use fast fourier transform;
Step F: judge in the described information that receives whether comprise random access code;
Judge whether that the method that comprises random access code can comprise:
1) by energy measuring, judges the existence that the random access sequence sign indicating number is arranged on which RACH subchannel; Or
2) detect by peak value, judge the existence that the random access sequence sign indicating number is arranged on which RACH subchannel.
Here simple the introduction detected the method that the existence of random access sequence sign indicating number is arranged on which RACH subchannel of judging by peak value:
I, the frequency-domain expression of local sequence and the described information of reception are carried out the frequency domain dot product;
II, (Inverse Discrete Fourier Transform IDFT) obtains the circulation time domain cross-correlation function of sequence to carry out contrary discrete Fourier transform (DFT);
III, detect described time domain cross-correlation function, draw the testing result that whether comprises random access code by the circulation peak detector.
Consult Fig. 7, the detailed process of described peak value detection and RTD estimation module is as follows:
1) the circulation auto-correlation function is divided into N
CS(the random access sequence sign indicating number cyclic shift number that system supports, and N
CS≤ T
PRE/ T
CP) section;
2) carry out following flow process for each section:
2a. each section is total to E sample input circulating register;
2b. use the L number value to the E-1 register as the Noise Estimation sample;
Whether satisfy decision threshold 2c. judge No. 0 pairing sample of register;
If it is 2cI., then be judged as the random access sequence sign indicating number and sent, and the cyclic shift number of times is inclined to one side when convert obtaining first footpath greater than thresholding;
If 2cII. the cyclic shift number of times surpasses D, then explanation does not exist random access sequence sign indicating number, process ends;
If, get back to the 2b place and re-execute 2cIII., then, the cyclic shift counter is increased by 1 with the displacement of the value ring shift left in the shift register less than thresholding.
Subcarrier number M in searching times D in the above flow process and cyclic shift length of window E and the RACH subchannel, cell coverage area (CP length T
CP) and the cyclic shift number N that supports of system
CSRelevant, it satisfies following relation.
E＝ceil(M/N
CS)
D＝ceil(T
CPM/T
PRE)
D≤E
Multipath spreading parameter L meets the following conditions:
Step G: when in the described information that receives, comprising random access code, obtain the RTD of subscriber equipment according to described random access code;
Cyclic shift number of times in the detailed process of above-mentioned Fig. 7 peak value detection and RTD estimation module and the corresponding relation of RTD are shown below:
N in the formula
CSIt is the reading of judging cyclic shift counter when the random access sequence sign indicating number is arranged first.Formula can draw the RTD that is handed down to subscriber equipment thus.
Step H: issue described RTD to described subscriber equipment.
Issue RTD behind described subscriber equipment, subscriber equipment promptly can utilize described RTD transmitting time, realizes uplink synchronous.
More than the invention provides accidental access method the 4th execution mode and have following technique effect at least:
1) the detection performance of random access sequence sign indicating number increases significantly
Consult Fig. 8, can find, reach 10 at the same time
-2The false dismissal probability condition under, adopt detection performance (lineae trapezoidea) that embodiment of the present invention obtained to be better than prior art LTE system at the detection performance (circular lines) of random access code 4dB nearly at random access code.
The main cause that produces performance gain is: after up channel was divided into the plurality of sub channel, the subchannel of arrowband dropped in the coherence bandwidth, therefore can overcome frequency selective fading; Adopted amplitude preferably can avoid whole narrow band signal to fall into the deep fading zone again simultaneously.
Therefore, can detect the random access sequence sign indicating number expeditiously and carry out processes such as follow-up uplink synchronous, communication efficiency is improved.
Certainly, down channel is divided into the plurality of sub channel, also can make the bandwidth of subchannel be equal to or greater than coherence bandwidth, because the subchannel bandwidth after cutting apart is littler than undivided total bandwidth, obviously the technique effect that these execution modes reached also is better than prior art.
2) can reduce the computational complexity of algorithm greatly
Owing to adopted the up subchannel of arrowband, adopted FDM and CDM to distinguish the user simultaneously, therefore under the prerequisite that does not reduce access-in resource, shortened the sequence length that is used to insert, thereby reduced user's relevant matches amount of calculation, the computation complexity of network side receiver can have been reduced by one more than the order of magnitude.
In other embodiments, be the LTE system of 5MHz for system bandwidth, can support the RACH channel of 4 1.25MHz.At this moment can adopt the method among the present invention equally,, utilize the TDD channel reciprocity to select the RACH channels transmit random access sequence sign indicating number of that little bandwidth of up channel decline for use for 1.25MHz according to descending channel information.
One of ordinary skill in the art will appreciate that all or part of step that realizes in the above-mentioned accidental access method execution mode is to instruct relevant hardware to finish by program, described program can be stored in the computer read/write memory medium, this program can comprise the content of aforementioned each execution mode of accidental access method of the present invention when carrying out.Here the alleged storage medium that gets, as: ROM/RAM, magnetic disc, CD etc.
The present invention also provides subscriber equipment first execution mode, comprises channel cutting unit 910, channel quality analysis unit 920, channel selected cell 930 and transmitting element 940.
Described channel cutting unit 910 is used for Random Access Channel is divided into the plurality of sub channel; Described channel quality analysis unit 920 is used for the reciprocity according to the up-downgoing channel, cuts apart the channel quality of the subchannel that obtains according to the described channel cutting unit 910 of the information analysis of described down channel; Described channel selected cell 930 is used for the plurality of sub channel in described Random Access Channel, selects up subchannel according to the described plurality of sub quality of channel that described channel quality analysis unit 920 draws; The up subchannel that described transmitting element 940 is used to adopt described channel selected cell 930 to select to obtain sends random access code.
Above first embodiment of the invention as can be seen, because present embodiment change prior art adopts accidental channel to upload the mode of random access code but at first adopts channel cutting unit 910 that Random Access Channel is divided into the plurality of sub channel, reduce the channel fading problem that upstream bandwidth causes greater than correlation bandwidth, next adopts the channel quality of channel quality analysis unit 920 according to the described Random Access Channel subchannel of the information analysis of down channel, adopt channel selected cell 930 to select up subchannel to send described random access code then according to subchannel quality, select up subchannel according to channel quality selectively, obviously improve the success rate that recipient's random access code detects, and then improve the efficient that inserts at random, avoid prior art to be difficult to detect the technological deficiency of described random access code owing to channel fading causes the recipient.
In other embodiments:
Described channel cutting unit 910 specifically is used for Random Access Channel is divided into the subchannel of some bandwidth less than coherence bandwidth;
Described channel quality analysis unit 920 is used to analyze the channel quality that draws described subchannel, comprise the decline situation of analyzing each several part channel in the described down channel, draw channel quality respectively with the described corresponding Random Access Channel subchannel of the decline negative correlation of described down channel each several part channel.Described channel selected cell 930 is used for selective channel, comprises selecting the Random Access Channel subchannel corresponding with local channel in the little down channel of channel fading as up subchannel.
The present invention also provides the network equipment first execution mode, comprises receiving element 1010, judging unit 1020, time delay acquiring unit 1030 and issues unit 1040.
Described receiving element 1010 is used to receive the information of utilizing the Random Access Channel subchannel to send;
Described judging unit 1020 is used for judging whether the information that described receiving element receives comprises random access code;
Described time delay acquiring unit 1030 is used for when the information that described judgment unit judges goes out to receive comprises random access code, obtains the RTD of subscriber equipment according to described random access code;
The described unit 1040 that issues is used to issue the RTD of described time delay acquiring unit acquisition to described subscriber equipment.
The corresponding the invention described above subscriber equipment of the above-mentioned network equipment first execution mode, unlike the prior art be to adopt receiving element 1010 to receive the information of utilizing the Random Access Channel subchannel to send; Whether comprise random access code in the information that adopts judging unit 1020 to judge that described receiving element receives, therefore improve the success rate that recipient's random access code detects, improve the efficient of access at random with the invention described above subscriber equipment first execution mode.
What deserves to be explained is that channel cutting unit 910, channel quality analysis unit 920, channel selected cell 930 and transmitting element 940 in aforementioned subscriber equipment first execution mode of the present invention can be integrated in the processing module; In like manner, each unit in the aforementioned network equipment of the present invention first execution mode also can be integrated in the processing module; Perhaps, any two or more in each unit of aforementioned each execution mode can be integrated in the processing module.
What deserves to be explained is that also each unit in subscriber equipment of the present invention, the network equipment execution mode both can adopt the form of hardware to realize, but the part that software is realized can adopt also the form of software function module to realize.Correspondingly, subscriber equipment of the present invention, network equipment execution mode both can be used as independently production marketing or use, sold in the computer read/write memory medium or used but the part that software is realized also can be stored in.
To sum up, the present invention can produce following technique effect at least:
1, improves the be detected as power of network side to the random sequence sign indicating number;
2, reduce the computational complexity of algorithm.
More than a kind of method, the network equipment and subscriber equipment that inserts at random provided by the present invention is described in detail by specific embodiment, the explanation of above embodiment just is used for helping to understand method of the present invention and thought thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present invention, the part that all can change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.
Claims (11)
1. a method that inserts at random is characterized in that, comprising:
Random Access Channel is divided into the plurality of sub channel according to coherence bandwidth, and the bandwidth that makes described subchannel is less than coherence bandwidth;
According to the reciprocity of up-downgoing channel, according to the channel quality of the described Random Access Channel subchannel of the information analysis of described down channel;
Select up subchannel according to the channel quality of described plurality of sub channel;
The up subchannel that adopts described selection to obtain sends random access code.
2. method according to claim 1 is characterized in that, the step that described information analysis according to down channel draws the channel quality of described Random Access Channel subchannel comprises:
Analyze the decline situation of each several part channel in the described down channel, draw channel quality respectively with the described corresponding Random Access Channel subchannel of the decline negative correlation of described down channel each several part channel.
3. method according to claim 2 is characterized in that, described channel quality according to the plurality of sub channel selects the step of up subchannel to comprise:
Select the Random Access Channel subchannel corresponding as up subchannel with the little down channel local channel of channel fading.
4. method according to claim 1 is characterized in that, the step that described information analysis according to down channel draws the channel quality of described Random Access Channel subchannel comprises:
Obtain the channel quality of described Random Access Channel subchannel according to the reciprocity of pilot tone in the described down channel and TDD channel.
5. method according to claim 1 is characterized in that, the step that the up subchannel that described employing selection obtains sends random access code comprises:
The up subchannel that adopts described selection to obtain, and adopt first ascending time slot behind the up-downgoing transfer point to send random access code.
6. a method that inserts at random is characterized in that, comprising:
The information that reception utilizes the Random Access Channel subchannel to send; Described subchannel is divided into the plurality of sub channel with described Random Access Channel according to coherence bandwidth and obtains, and the bandwidth of described subchannel is less than coherence bandwidth;
Judge in the described information that receives and whether comprise random access code;
When in the described information that receives, comprising random access code, obtain the round trip time delay RTD of subscriber equipment according to described random access code;
Issue described RTD to described subscriber equipment.
7. method according to claim 6 is characterized in that, whether comprises in the information that described judgement receives that the step of random access code comprises:
The frequency-domain expression of local sequence and the described information of reception are carried out the frequency domain dot product;
Carry out the circulation time domain cross-correlation function of contrary discrete Fourier transform (DFT) IDFT acquisition sequence;
Detect described time domain cross-correlation function by the circulation peak detector, draw the testing result that whether comprises random access code.
8. a subscriber equipment is characterized in that, comprising:
The channel cutting unit is used for Random Access Channel is divided into the plurality of sub channel according to coherence bandwidth, and the bandwidth that makes described subchannel is less than coherence bandwidth;
Channel quality analysis unit is used for the reciprocity according to the up-downgoing channel, cuts apart the channel quality of the subchannel that obtains according to the described channel cutting unit of the information analysis of described down channel;
The channel selected cell is used for selecting up subchannel according to the described plurality of sub quality of channel that described channel quality analysis unit draws;
Transmitting element, the up subchannel that is used to adopt described channel selected cell to select to obtain sends random access code.
9. subscriber equipment according to claim 8 is characterized in that,
Described channel quality analysis unit is used to analyze the channel quality that draws described subchannel, comprise the decline situation of analyzing each several part channel in the described down channel, draw channel quality respectively with the described corresponding Random Access Channel subchannel of the decline negative correlation of described down channel each several part channel.
10. subscriber equipment according to claim 9 is characterized in that,
Described channel selected cell is used for selective channel, comprises that the corresponding Random Access Channel subchannel of the little down channel local channel of selection and channel fading is as up subchannel.
11. a network equipment is characterized in that, comprising:
Receiving element is used to receive the information of utilizing the Random Access Channel subchannel to send; Described subchannel is divided into the plurality of sub channel with described Random Access Channel according to coherence bandwidth and obtains, and the bandwidth of described subchannel is less than coherence bandwidth;
Judging unit is used for judging whether the information that described receiving element receives comprises random access code;
The time delay acquiring unit is used for when the information that described judgment unit judges goes out to receive comprises random access code, obtains the RTD of subscriber equipment according to described random access code;
Issue the unit, be used to issue the RTD of described time delay acquiring unit acquisition to described subscriber equipment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007101275196A CN101335986B (en) | 2007-06-28 | 2007-06-28 | Method, network equipment and user equipment for random access |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007101275196A CN101335986B (en) | 2007-06-28 | 2007-06-28 | Method, network equipment and user equipment for random access |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101335986A CN101335986A (en) | 2008-12-31 |
| CN101335986B true CN101335986B (en) | 2011-11-02 |
Family
ID=40198226
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007101275196A Active CN101335986B (en) | 2007-06-28 | 2007-06-28 | Method, network equipment and user equipment for random access |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101335986B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103298136B (en) * | 2012-02-29 | 2016-11-23 | 华为技术有限公司 | A kind of accidental access method, terminal, base station and system |
| CN103079227B (en) * | 2013-02-05 | 2015-04-29 | 武汉邮电科学研究院 | Random access detection method and system used in LTE (Long Term Evolution) system |
| CN104993858B (en) * | 2015-06-01 | 2018-07-20 | 武汉拓宝科技股份有限公司 | A kind of TDD communication means |
| CN108024359B (en) | 2016-11-04 | 2022-01-14 | 华为技术有限公司 | Uplink access method, base station and user equipment |
| EP3471364B1 (en) | 2017-05-03 | 2023-08-09 | LG Electronics Inc. | Method for transmitting random access channel signal, user equipment, method for receiving random access channel signal, and base station |
| CN110247743B (en) * | 2018-03-08 | 2021-11-19 | 中国移动通信有限公司研究院 | Random access method, device, equipment and storage medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1371584A (en) * | 1999-08-27 | 2002-09-25 | 西门子公司 | Method for allocating transmission resources of uplink of radio transmission |
| CN1533199A (en) * | 2003-03-18 | 2004-09-29 | 大唐移动通信设备有限公司 | Method for detecting user's terminal random cut-in |
| CN1941689A (en) * | 2005-09-29 | 2007-04-04 | 上海原动力通信科技有限公司 | Method for dispatching sub-frequency band of time-division duplex OFDM system |
-
2007
- 2007-06-28 CN CN2007101275196A patent/CN101335986B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1371584A (en) * | 1999-08-27 | 2002-09-25 | 西门子公司 | Method for allocating transmission resources of uplink of radio transmission |
| CN1533199A (en) * | 2003-03-18 | 2004-09-29 | 大唐移动通信设备有限公司 | Method for detecting user's terminal random cut-in |
| CN1941689A (en) * | 2005-09-29 | 2007-04-04 | 上海原动力通信科技有限公司 | Method for dispatching sub-frequency band of time-division duplex OFDM system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101335986A (en) | 2008-12-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1571770B1 (en) | Apparatus and method for assigning a ranging channel and transmitting and receiving a ranging signal in an OFDM system | |
| KR100865251B1 (en) | Method and apparatus for pilot signal transmission | |
| EP1681821B1 (en) | Preamble sequences for a multicarrier communication system using a multiple input multiple output scheme | |
| EP3447941B1 (en) | Communication device and method | |
| KR100856249B1 (en) | Method for detecting initial action mode in a wireless communication system | |
| EP2439973B1 (en) | Detection method and apparatus based on random access process | |
| US7599327B2 (en) | Method and apparatus for accessing a wireless communication system | |
| EP2218227B1 (en) | Channel estimation for synchronized cells in a cellular communication system | |
| US9398617B2 (en) | Methods and apparatus for random access in a communication system | |
| US8331298B2 (en) | Structure and construction method of uplink control channel in mobile wideband wireless access system | |
| EP1811691A2 (en) | Apparatus and method for transmitting and receiving a RACH signal in SC-FDMA system | |
| US20100110873A1 (en) | Method of transmitting synchronization signal in wireless communication system | |
| EP3206328A1 (en) | Channel sounding using multiple sounding signal configurations | |
| CN101335986B (en) | Method, network equipment and user equipment for random access | |
| EP2621110A1 (en) | Reference signal generation apparatus and preamble sequence detection apparatus using the same | |
| JP2017527212A (en) | Simple RACH (SRACH) | |
| EP1762018A2 (en) | Method and apparatus for accessing a wireless multi-carrier communication system | |
| KR20050040988A (en) | Communication method for frequency hopping ofdm based cellular system | |
| KR20070077013A (en) | Wireless communication system and wireless communication method | |
| US8374452B2 (en) | Method and apparatus for fast cell search | |
| Zeng et al. | A novel OFDMA ranging method exploiting multiuser diversity | |
| US8630279B2 (en) | Method for generating downlink signal, and method for searching cell | |
| CN101094027B (en) | Transmitting and receiving method concealing signature sequence of sending structure of user's control information | |
| US11109330B2 (en) | Method for determining correction time in wireless communication system and apparatus therefor | |
| Hatamoto et al. | A study on a cell search method for dynamic parameter controlled OF/TDMA systems downlink |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |