CN101488931A - Transmitting, capturing method for OFDM, device and system therefor - Google Patents
Transmitting, capturing method for OFDM, device and system therefor Download PDFInfo
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Abstract
An embodiment of the invention discloses an Orthogonal Frequency Division Multiplexing (OFDM) synchronous channel transmission and capture method, device and system by using the method, which solves OFDM down synchronizing problem and broadcast channel capture problem. In the embodiment of the invention, the frame number of frame in superframe is scrambled for synchronizing channel so that the frame number of the frame where the synchronizing channel is can be obtained when a terminal captures the synchronizing channel. The boundary of superframe and frame where the broadcast channel is can be located by the frame number so that the broadcast channel of each superframe having one transmission can be captured. The method is mainly used in OFDM and OFDMA system.
Description
Technical field
The present invention relates to the orthogonal frequency division multiplexi in the broadband wireless communications field, be particularly related to the transmission method and the equipment of the synchronizing channel in the orthogonal frequency division multiplexi, and the catching method of broadcast channel and equipment, and the system that adopts above-mentioned synchronization channel transmissions method and broadcast channel catching method.
Background technology
OFDM (OFDM) technology is divided into some orthogonal sub-channels with channel, converts high-speed data signal to parallel low speed sub data flow, is modulated on each subchannel and transmits.Because the signal bandwidth on each subchannel is less than the correlation bandwidth of channel, so each subchannel can regard the flatness fading channel as, thereby can eliminate intersymbol interference.In OFDM (OFDMA) system, the user can the selective channel condition preferably subchannel carry out transfer of data, and in whole frequency band, send, thereby guaranteed that each subcarrier is all used by the more excellent user of respective channels condition unlike the OFDM technology.
Fig. 1 is a kind of frame structure based on OFDM or OFDMA system, and frame structure comprises: a series of superframe, and each superframe comprises a plurality of frames, and every frame comprises a plurality of subframes, and each subframe comprises a plurality of OFDM symbols.At least comprise broadcast channel (BCH) in the superframe, and one or more synchronizing channel (SCH).The effect of synchronizing channel is to make terminal can catch serving BS and synchronous with the base station maintenance, and synchronizing channel can also allow terminal recognition provide the sector of service for it simultaneously.
The structure of synchronizing channel mainly comprises following two kinds:
A kind of structure of synchronizing channel as shown in Figure 2, base station periodic transfer synchronizing channel and broadcast channel, synchronizing channel comprises two channels: primary synchronization channel (P-SCH) and auxiliary synchronization channel (S-SCH).Primary synchronization channel is positioned at the penult OFDM symbol of preamble (preamble) subframe, the primary synchronization channel that all sectored transmissions are the same, realize quick Time and Frequency Synchronization, auxiliary synchronization channel is positioned at last OFDM symbol of preamble subframe, the carrying sector mark is used to distinguish different sectors.Broadcast channel takies other OFDM symbols of preamble subframe, is used for carrying OFDM or OFDMA system parameters.
The structure of another kind of synchronizing channel as shown in Figure 3, base station periodic transfer synchronizing channel and broadcast channel, synchronizing channel is positioned at first OFDM symbol of preamble subframe, the carrying sector mark is used to distinguish different sectors and realizes quick Time and Frequency Synchronization.Broadcast channel takies other one or several OFDM symbols of preamble subframe, is used for carrying OFDM or OFDMA system parameters.
The base station may be inequality to the cycle of synchronizing channel and broadcast channel transmission, and for example, the normal now scheme that adopts is: synchronizing channel can every frame transmission primaries, the then every superframe transmissions of broadcast channel once, its superframe structure signal is as shown in Figure 4.
When adopting the transmission cycle of Fig. 4, because terminal is when the search synchronizing channel, can in same superframe, produce four more intense relevant peaks, can determine the position of four frame boundaries in the superframe by these four stronger relevant peaks, thereby can more easily capture synchronizing channel.Because the transmission cycle of broadcast channel and the transmission cycle of superframe are consistent, just can capture broadcast channel so need identify the border of superframe.But because terminal and do not know the position of every frame in superframe, so just can not determine the position of superframe boundaries, and every superframe only transmits a broadcast channel (Figure 4 shows that transmitting broadcasting channel in first frame of superframe), cause terminal not know and promptly can't correctly catch broadcast channel at which concrete frame-grab broadcast channel.
Generally speaking, as long as broadcast channel is not when transmitting with synchronous channel fully, all can causes because of locating broadcast channel and cause and correctly to catch broadcast channel.
Summary of the invention
On the one hand, embodiments of the invention provide a kind of synchronization channel transmissions method of OFDM, can make things convenient for catching of broadcast channel when transfer synchronous channel.
On the other hand, embodiments of the invention also provide a kind of broadcast channel catching method of OFDM, at broadcast channel and when not exclusively channel transmits together in company with the step, can correctly catch broadcast channel.
On the one hand, embodiments of the invention also provide a kind of base station, are convenient to catching of broadcast channel when transfer synchronous channel again.
Again on the one hand, embodiments of the invention also provide a kind of communication terminal, at broadcast channel and when not exclusively channel transmits together in company with the step, can correctly catch broadcast channel.
Again on the one hand, embodiments of the invention also provide a kind of ofdm system, at broadcast channel and when not exclusively channel transmits together in company with the step, make communication terminal can capture the broadcast channel of base station.
For achieving the above object, embodiments of the invention adopt following technical scheme:
A kind of synchronization channel transmissions method of OFDM comprises:
Extract the frame number of at least one frame in the superframe;
Utilize described frame number to synchronization channel scrambling;
Synchronizing channel in the frame of described frame number correspondence after the transmission scrambling.
A kind of broadcast channel catching method of OFDM comprises:
The frame number of recorded announce channel place frame;
Catch synchronizing channel;
The synchronizing channel that captures is carried out descrambling, obtain the current frame number of this synchronizing channel place frame;
Frame number and current frame number according to broadcast channel place frame are caught broadcast channel.
A kind of base station comprises:
Extraction module is used for extracting the frame number of at least one frame of superframe;
Scrambling module utilizes described frame number to synchronization channel scrambling;
Broadcast module is used for transmitting broadcasting channel at least one frame of superframe; And in the frame of described frame number correspondence the synchronizing channel of transmission after the scrambling.
A kind of communication terminal comprises:
Memory module is used for the frame number of recorded announce channel place frame;
Trapping module is used to catch synchronizing channel;
Descrambling module is used for the synchronizing channel that captures is carried out descrambling, obtains the current frame number of this synchronizing channel place frame;
Described trapping module is caught broadcast channel according to the frame number and the current frame number of broadcast channel place frame.
A kind of ofdm system comprises base station and communication terminal;
Described base station comprises:
Extraction module is used for extracting the frame number of at least one frame of superframe;
Scrambling module utilizes described frame number to synchronization channel scrambling;
Broadcast module is used for transmitting broadcasting channel at least one frame of superframe; And in the frame of described frame number correspondence the synchronizing channel of transmission after the scrambling;
Described communication terminal comprises:
Memory module is used for the frame number of recorded announce channel place frame;
Trapping module is used for catching the synchronizing channel that the base station broadcast module is transmitted;
Descrambling module is used for the synchronizing channel that captures is carried out descrambling, obtains the current frame number of this synchronizing channel place frame;
The broadcast channel that described trapping module is caught broadcast module transmission in the base station according to the frame number and the current frame number of broadcast channel place frame.
The described embodiment of the invention of technique scheme, when a synchronizing channel is transmitted in the base station in every frame, and in every superframe during broadcast channel of transmission, need utilize this synchronizing channel under the frame number of frame in superframe to synchronization channel scrambling.Terminal can be determined frame boundaries by the power of relevant peaks, catches the synchronizing channel in the frame then, and to obtaining the frame number of frame under this current synchronizing channel of catching behind its descrambling.The position of broadcast channel channel can be determined by the frame number of current frame number and broadcast channel place frame, and then broadcast channel can be correctly caught.Can capture broadcast channel by the embodiment of the invention, solve broadcast channel effectively and when not exclusively channel transmitted together in company with the step, the broadcast channel that causes was caught inaccurate problem.
Description of drawings
Fig. 1 is the frame assumption diagram of OFDM and OFDMA system in the prior art;
Fig. 2 is the structure chart of first kind of synchronizing channel and broadcast channel in the prior art;
Fig. 3 is the structure chart of second kind of synchronizing channel and broadcast channel in the prior art;
Fig. 4 is the schematic diagram of synchronizing channel and broadcast channel transmission cycle in the prior art;
Fig. 5 is the base station schematic diagram of first embodiment of the invention;
Fig. 6 is the flow chart of catching of first embodiment of the invention;
Fig. 7 is the terminal structure schematic diagram of first embodiment of the invention;
Fig. 8 is the flow chart of catching of second embodiment of the invention;
Fig. 9 is the terminal structure schematic diagram of second embodiment of the invention;
The base station schematic diagram of Figure 10 third embodiment of the invention;
Figure 11 third embodiment of the invention catch flow chart;
Figure 12 is the base station schematic diagram of fourth embodiment of the invention;
Figure 13 is the flow chart of catching of fourth embodiment of the invention;
Figure 14 is wherein a kind of terminal structure schematic diagram of fourth embodiment of the invention;
Figure 15 is the another kind of terminal structure schematic diagram of fourth embodiment of the invention.
Embodiment
Embodiments of the invention utilize the frame number of frame in superframe that synchronizing channel is carried out scrambling, like this at capture terminal after synchronizing channel, just can be by the synchronizing channel descrambling be obtained frame number, and catch every superframe transmissions broadcast channel once by frame number.
Embodiments of the present invention is described in detail below in conjunction with accompanying drawing.
Embodiment 1:
In the present embodiment, synchronizing channel has comprised primary synchronization channel (P-SCH) and auxiliary synchronization channel (S-SCH), include 4 frames in the superframe of this base station transmits, low two of the frame number of every frame is followed successively by: 00,01,10,11, and every frame transmission primaries synchronizing channel, and broadcast channel of every superframe transmissions (in frame number is 00 frame, carrying broadcast channel).As shown in Figure 5, the base station is as follows to the processing of auxiliary synchronization channel:
At first, generate a S-SCH sequence, the carrying sector mark is used to distinguish different sectors; Secondly, extract the frame number of present frame in superframe, and utilize the frame number of present frame in superframe to the S-SCH scrambling, because every superframe has only four frames in the present embodiment, so can come scrambling with low two of frame number, if the frame number that comprises in every superframe is more, then can utilize in the frame number more figure places to come scrambling; Then the S-SCH after the scrambling is carried out subcarrier mapping and orthogonal frequency division modulated is handled, last periodic transfer synchronizing channel (P-SCH and S-SCH) according to frame, and according to the periodic transfer broadcast channel BCH of superframe.
In above-mentioned scrambling process, can be by frame number and P-SCH simultaneously to the S-SCH scrambling, to improve the fail safe of S-SCH scrambling.
In order can to communicate with the base station, communication terminal must be on time and frequency and base station synchronization, has write down the frame number of broadcast channel place frame in this communication terminal in advance, and its concrete synchronizing process is specially as shown in Figure 6:
601, catch synchronizing channel, comprise P-SCH and S-SCH, utilize P-SCH to realize time synchronized and Frequency Synchronization then;
602, the S-SCH signal that receives is carried out the rectification operation of OFDM, and separate the subcarrier map operation, obtain the S-SCH after the scrambling;
603, the S-SCH after the scrambling is carried out descrambling, obtain S-SCH and the present frame frame number in superframe;
604, with the S-SCH sequence of local storage and descrambling to the S-SCH signal carry out relevantly, obtain sector mark, be used for discerning the sector at this communication terminal place;
605, the relatively frame number of BCH place frame of regulation and the frame number that descrambling obtains, if both are identical, just represent broadcast channel and in current synchronizing channel of catching in same frame, then in this present frame, continue to catch BCH, and execution in step 606; Otherwise return step 601;
606, decoding BCH obtains system parameters entrained among the BCH.
Corresponding to the method for above-mentioned transfer synchronous channel and broadcast channel, and the method for catching broadcast channel, embodiments of the invention provide the base station of transfer synchronous channel and broadcast channel, and the communication terminal of catching broadcast channel.
As shown in Figure 5, base station in the present embodiment has increased scrambling module and extraction module than base station of the prior art, and concrete processing procedure is: at first, and by S-SCH sequence of sequencer generation of S-SCH, the carrying sector mark is used to distinguish different sectors; Secondly, extract the frame number of present frame in superframe by extraction module, and utilize the frame number of present frame in superframe to the S-SCH scrambling by scrambling module, because every superframe has only four frames in the present embodiment, so can come scrambling with low two of frame number, if the frame number that comprises in every superframe is more, then can utilize in the frame number more figure places to come scrambling; Then the S-SCH after the scrambling is carried out subcarrier mapping and orthogonal frequency division modulated is handled, last periodic transfer synchronizing channel (P-SCH and S-SCH) according to frame, and according to the periodic transfer broadcast channel BCH of superframe.
The rectification operation of the OFDM that communication terminal adopted that present embodiment provides, and it is identical with prior art to separate the subcarrier map operation, it is distinguished as shown in Figure 7, and this communication terminal also comprises:
Trapping module is used to catch synchronizing channel, comprises P-SCH and S-SCH, and P-SCH wherein is used to realize time synchronized and Frequency Synchronization;
Descrambling module is used for the S-SCH of the synchronizing channel that captures is carried out descrambling, obtains S-SCH, and the current frame number of this S-SCH place frame, and S-SCH wherein is used for discerning the sector at this communication terminal place;
Memory module is used to preserve the frame number of broadcast channel place frame;
Comparison module is used for the frame number of more current frame number and broadcast channel place frame, and when the frame number of current frame number and broadcast channel place frame was identical, the control trapping module was caught broadcast channel in the frame of current frame number correspondence.
Embodiment 2:
If broadcast channel is certain and synchronizing channel in same frame, can adopt the broadcast channel catching method among the embodiment 1, get along well synchronizing channel during when broadcast channel at same frame, the catching method among the embodiment 1 just can't capture broadcast channel.
For example: synchronizing channel is transmitted by first frame in the superframe and the 3rd frame, and broadcast channel is transmitted by second frame in the superframe, so when transmitting, only need to extract the frame number of first frame and the 3rd frame, frame number with synchronizing channel utilization correspondence carries out scrambling then, transmits the synchronizing channel after the scrambling again.
In order to capture broadcast channel during at same frame in broadcast channel discord synchronizing channel, another kind of synchronizing process also is provided in the present embodiment, the frame number of recorded announce channel place frame in advance in communication terminal as shown in Figure 8, is specially:
801, catch synchronizing channel, comprise P-SCH and S-SCH, utilize P-SCH to realize time synchronized and Frequency Synchronization then;
802, the S-SCH signal that receives is carried out the rectification operation of OFDM, and separate the subcarrier map operation, obtain the S-SCH after the scrambling;
803, the S-SCH after the scrambling is carried out descrambling, obtain S-SCH and the present frame frame number in superframe;
804, with the S-SCH sequence of local storage and descrambling to the S-SCH signal carry out relevantly, obtain sector mark, be used for discerning the sector at this communication terminal place;
805, determine the frame number of each frame in superframe boundaries and the superframe according to current frame number and frame length; Detailed process is: the integral multiple of frame length is calculated on the border of present frame forward or backward, can determine the border of other frames, utilizes the frame number of present frame to extrapolate the frame number of other frames then, so just can determine the border of each superframe;
806, in superframe, search broadcast channel place frame according to the frame number of broadcast channel place frame; And the control trapping module is caught broadcast channel in the frame that finds.Concrete operations are: the frame number by each frame number in the superframe and broadcast channel place frame compares, if equate, just catches broadcast channel in this frame, and execution in step 607; , otherwise then take the frame number of next frame in the superframe to come comparison, the broadcast channel in finding this superframe.
807, decoding BCH obtains system parameters entrained among the BCH.
Owing to extrapolated all frame numbers in the superframe (comprising the frame that does not carry synchronizing channel) in the said method, so just can in all frames, search, so that catch broadcast channel according to the frame number of broadcast channel place frame.
The structure of the base station that method is used of transfer synchronous channel and architecture of base station shown in Figure 5 are identical in the present embodiment, just scrambling module need be handled each frame in embodiment 1, and only needs to handle first frame and the 3rd frame in each superframe in the present embodiment.
Corresponding to above-mentioned method for synchronous, present embodiment also provides another kind of communication terminal, the rectification operation of the OFDM that this communication terminal adopted, and it is identical with prior art to separate the subcarrier map operation, and it is distinguished as shown in Figure 9, and this communication terminal comprises:
Trapping module is used to catch synchronizing channel, comprises P-SCH and S-SCH, and P-SCH wherein is used to realize time synchronized and Frequency Synchronization;
Descrambling module is used for the S-SCH of the synchronizing channel that captures is carried out descrambling, obtains S-SCH, and the current frame number of this S-SCH place frame, and S-SCH wherein is used for discerning the sector at this communication terminal place;
Locating module is used for determining according to current frame number and frame length the frame number of superframe boundaries and each frame of superframe; Detailed process is: the integral multiple of frame length is calculated on the border of present frame forward or backward, can determine the border of other frames, utilizes the frame number of present frame to extrapolate the frame number of other frames then, so just can determine the border of each superframe;
Memory module is used to preserve the frame number of broadcast channel place frame;
Search module, be used for searching broadcast channel place frame at superframe according to the frame number of broadcast channel place frame; And the control trapping module is caught broadcast channel in the frame that finds.In general search module and be exactly take each frame number and broadcast channel place frame in the superframe frame number relatively, if equate, just in this frame, catch broadcast channel, otherwise then take the frame number of next frame in the superframe to come comparison, the broadcast channel in finding this superframe.
Embodiment 3:
In the present embodiment, synchronizing channel has only comprised primary synchronization channel (P-SCH), include 4 frames in the superframe of this base station transmits, low two of the frame number of every frame is followed successively by: 00,01,10,11, and every frame transmission primaries synchronizing channel, and broadcast channel of every superframe transmissions (in frame number is 00 frame, carrying broadcast channel).As shown in figure 10, the base station is as follows to the processing of primary synchronization channel:
At first, generate a P-SCH sequence, be used to carry out time synchronized and Frequency Synchronization, carry sector mark simultaneously, be used to distinguish different sectors; Secondly, extract the frame number of present frame in superframe, and utilize the frame number of present frame in superframe to the P-SCH scrambling, because every superframe has only four frames in the present embodiment, so can come scrambling with low two of frame number, if the frame number that comprises in every superframe is more, then can utilize in the frame number more figure places to come scrambling; Then the P-SCH after the scrambling is carried out subcarrier mapping and orthogonal frequency division modulated is handled, last periodic transfer primary synchronization channel (P-SCH) according to frame, and according to the periodic transfer broadcast channel BCH of superframe.
In order can to communicate with the base station, communication terminal must be on time and frequency and base station synchronization, the frame number of recorded announce channel place frame in advance in communication terminal, and its synchronizing process is specially as shown in figure 11:
1101, the P-SCH signal that receives is carried out the rectification operation of OFDM, and separate the subcarrier map operation, obtain the P-SCH of scrambling;
1102, the P-SCH to scrambling carries out descrambling, obtains P-SCH and the present frame frame number in superframe; Then with the P-SCH sequence of local storage and descrambling to the P-SCH signal carry out relevantly, realize time synchronized and Frequency Synchronization, and discern the sector at this communication terminal place.
1103, the relatively frame number of BCH place frame of regulation and the frame number that descrambling obtains, if both are identical, just represent broadcast channel and at current primary synchronization channel of catching in same frame, then in this present frame, continue to catch BCH, and execution in step 1104; Otherwise return step 1101;
1104, decoding BCH obtains system parameters entrained among the BCH.
When broadcast channel discord synchronizing channel during at same frame, calculate after the current frame number, can adopt the catching method among the embodiment 2 to capture broadcast channel.
Corresponding to the method for above-mentioned transfer synchronous channel and broadcast channel, and the method for catching broadcast channel, embodiments of the invention provide the base station of transfer synchronous channel and broadcast channel, and the communication terminal of catching broadcast channel.
As shown in figure 10, the base station in the present embodiment has increased scrambling module and extraction module than base station of the prior art, only the sequencer of the S-SCH among Fig. 5 need be changed into the sequencer of P-SCH.
The module that communication terminal in the present embodiment adopts and Fig. 7 or Fig. 9 are identical, and different is that the data that descrambling module is handled change to some extent, is specially:
Descrambling module is used for the data that capture are carried out descrambling, obtains P-SCH, and the current frame number of this P-SCH place frame, and P-SCH wherein is used for realizing time synchronized and Frequency Synchronization, and discerns the sector at this communication terminal place.
Embodiment 4:
In the present embodiment, synchronizing channel has comprised primary synchronization channel (P-SCH) and auxiliary synchronization channel (S-SCH), include 4 frames in the superframe of this base station transmits, low two of the frame number of every frame is followed successively by: 00,01,10,11, and every frame transmission primaries synchronizing channel, and broadcast channel of every superframe transmissions (in frame number is 00 frame, carrying broadcast channel).As shown in figure 12, the base station is as follows to the processing of auxiliary synchronization channel:
At first, generate a S-SCH sequence, the carrying sector mark is used to distinguish different sectors; Secondly, extract the frame number of present frame in superframe, and utilize the frame number of present frame in superframe to the S-SCH scrambling, because every superframe has only four frames in the present embodiment, so can come scrambling with low two of frame number, if the frame number that comprises in every superframe is more, then can utilize in the frame number more figure places to come scrambling; Once more, need carry out discrete Fourier transform (DFT) (DFT) to the P-SCH after the scrambling; To carrying out the S-SCH after the DFT conversion, carry out subcarrier mapping and orthogonal frequency division modulated and handle then, last periodic transfer synchronizing channel (P-SCH and S-SCH) according to frame, and according to the periodic transfer broadcast channel BCH of superframe.
In order can to communicate with the base station, communication terminal must be on time and frequency and base station synchronization, the frame number of recorded announce channel place frame in advance in communication terminal, and its synchronizing process is specially as shown in figure 13:
1301, catch synchronizing channel, comprise P-SCH and S-SCH, utilize P-SCH to realize time synchronized and Frequency Synchronization then;
1302, the S-SCH signal that receives is carried out the rectification operation of OFDM, and separate the subcarrier map operation;
1303, this S-SCH signal that receives is carried out anti-discrete Fourier transform (DFT) (IDFT) operation, obtain the S-SCH of scrambling;
1304, the S-SCH to scrambling carries out descrambling, obtains S-SCH and the present frame frame number in superframe;
1305, with the S-SCH sequence of local storage and descrambling to the S-SCH signal carry out relevantly, obtain sector mark, be used for discerning the sector at this communication terminal place;
1306, the relatively frame number of BCH place frame of regulation and the frame number that descrambling obtains, if both are identical, just represent broadcast channel and in current synchronizing channel of catching in same frame, then in this present frame, continue to catch BCH, and execution in step 1307; Otherwise return step 1301;
1307, decoding BCH obtains system parameters entrained among the BCH.
Corresponding to the method for above-mentioned transfer synchronous channel and broadcast channel, and the method for catching broadcast channel, embodiments of the invention provide the base station of transfer synchronous channel and broadcast channel, and the communication terminal of catching broadcast channel.
When broadcast channel discord synchronizing channel during at same frame, calculate after the current frame number, can adopt the catching method among the embodiment 2 to capture broadcast channel.
As shown in figure 12, the base station in the present embodiment has increased scrambling module and extraction module and conversion module than base station of the prior art.The concrete processing procedure of this base station is: at first, by S-SCH sequence of sequencer generation of S-SCH, the carrying sector mark is used to distinguish different sectors; Secondly, extract the frame number of present frame in superframe by extraction module, and utilize the frame number of present frame in superframe to the S-SCH scrambling by scrambling module, because every superframe has only four frames in the present embodiment, so can come scrambling with low two of frame number, if the frame number that comprises in every superframe is more, then can utilize in the frame number more figure places to come scrambling; Once more, the S-SCH after utilizing conversion module to scrambling carries out discrete Fourier transform (DFT); Then the S-SCH after the scrambling is carried out subcarrier mapping and orthogonal frequency division modulated is handled, last periodic transfer synchronizing channel (P-SCH and S-SCH) according to frame, and according to the periodic transfer broadcast channel BCH of superframe.
The rectification operation of the OFDM that communication terminal adopted that present embodiment provides, and it is identical with prior art to separate the subcarrier map operation, it is distinguished as shown in figure 14, and this communication terminal also comprises:
Trapping module is used to catch synchronizing channel, comprises P-SCH and S-SCH, and P-SCH wherein is used to realize time synchronized and Frequency Synchronization;
Inverse transform block is carried out anti-discrete Fourier transform (DFT) to P-SCH and the S-SCH that captures;
Descrambling module is used for the S-SCH after the inverse transformation is carried out descrambling, obtains S-SCH, and the current frame number of this S-SCH place frame, and S-SCH wherein is used for discerning the sector at this communication terminal place;
Memory module is used to preserve the frame number of broadcast channel place frame;
Comparison module is used for the frame number of more current frame number and broadcast channel place frame, and when the frame number of current frame number and broadcast channel place frame was identical, the control trapping module was caught broadcast channel in the frame of current frame number correspondence.
Present embodiment also provides another kind of communication terminal, this communication terminal is to have increased an inverse transform block on the basis of Fig. 9, specifically as shown in figure 15, this inverse transform block is carried out anti-discrete Fourier transform (DFT) to P-SCH and the S-SCH that captures, and then the S-SCH after the inverse transformation is input to descrambling module and carries out descrambling.
Embodiments of the invention mainly are used in ofdm system and the OFDMA system, carry out Time and Frequency Synchronization, and the current affiliated sector of definite communication terminal.
The above; only be the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; can expect easily changing or replacing, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.
Claims (22)
1, a kind of synchronization channel transmissions method of OFDM is characterized in that comprising:
Extract the frame number of at least one frame in the superframe;
Utilize described frame number to synchronization channel scrambling;
Synchronizing channel in the frame of described frame number correspondence after the transmission scrambling.
2, the synchronization channel transmissions method of OFDM according to claim 1 is characterized in that, describedly utilizes described frame number also to comprise after the step of synchronization channel scrambling: the synchronizing channel after the scrambling is carried out discrete Fourier transform (DFT).
3, the synchronization channel transmissions method of OFDM according to claim 1, it is characterized in that, describedly utilize described frame number that synchronization channel scrambling is specially: to utilize described frame number to the primary synchronization channel scrambling in the synchronizing channel, perhaps utilize described frame number to the auxiliary synchronization channel scrambling in the synchronizing channel.
4, the synchronization channel transmissions method of OFDM according to claim 1 is characterized in that, described frame number is represented by the low level of the corresponding binary number of frame number.
5, a kind of broadcast channel catching method of OFDM is characterized in that comprising:
The frame number of recorded announce channel place frame;
Catch synchronizing channel;
The synchronizing channel that captures is carried out descrambling, obtain the current frame number of this synchronizing channel place frame;
Frame number and current frame number according to broadcast channel place frame are caught broadcast channel.
6, the broadcast channel catching method of OFDM according to claim 5 is characterized in that, described the synchronizing channel that captures is carried out also comprising before the step of descrambling: the synchronizing channel that captures is carried out anti-discrete Fourier transform (DFT).
7, the broadcast channel catching method of OFDM according to claim 5, it is characterized in that, describedly utilize described frame number that synchronization channel scrambling is specially: to utilize described frame number to the primary synchronization channel scrambling in the synchronizing channel, perhaps utilize described frame number to the auxiliary synchronization channel scrambling in the synchronizing channel.
8, the broadcast channel catching method of OFDM according to claim 5 is characterized in that, described frame number and current frame number according to broadcast channel place frame caught broadcast channel and comprised:
The frame number of more current frame number and broadcast channel place frame;
If current frame number is identical with the frame number of broadcast channel place frame, then in the frame of current frame number correspondence, catch broadcast channel.
9, the broadcast channel catching method of OFDM according to claim 5 is characterized in that, described frame number and current frame number according to broadcast channel place frame caught broadcast channel and comprised:
Determine the frame number of each frame in superframe boundaries and the superframe according to current frame number and frame length;
In superframe, search broadcast channel place frame according to the frame number of broadcast channel place frame;
In the frame that finds, catch broadcast channel.
10, the broadcast channel catching method of OFDM according to claim 5 is characterized in that, described frame number is represented by the low level of the corresponding binary number of frame number.
11, a kind of base station is characterized in that comprising:
Extraction module is used for extracting the frame number of at least one frame of superframe;
Scrambling module utilizes described frame number to synchronization channel scrambling;
Broadcast module is used for transmitting broadcasting channel at least one frame of superframe; And in the frame of described frame number correspondence the synchronizing channel of transmission after the scrambling.
12, base station according to claim 11 is characterized in that also comprising: conversion module is used for the synchronizing channel after the scrambling is carried out discrete Fourier transform (DFT).
13, a kind of communication terminal is characterized in that comprising:
Memory module is used for the frame number of recorded announce channel place frame;
Trapping module is used to catch synchronizing channel;
Descrambling module is used for the synchronizing channel that captures is carried out descrambling, obtains the current frame number of this synchronizing channel place frame;
Described trapping module is caught broadcast channel according to the frame number and the current frame number of broadcast channel place frame.
14, communication terminal according to claim 12 is characterized in that also comprising: inverse transform block is used for the synchronizing channel that captures is carried out anti-discrete Fourier transform (DFT), and outputs to descrambling module.
15, communication terminal according to claim 12 is characterized in that also comprising:
Comparison module is used for the frame number of more current frame number and broadcast channel place frame, and when the frame number of current frame number and broadcast channel place frame was identical, the control trapping module was caught broadcast channel in the frame of current frame number correspondence.
16, communication terminal according to claim 12 is characterized in that also comprising:
Locating module is used for determining according to current frame number and frame length the frame number of superframe boundaries and each frame of superframe;
Search module, be used for searching broadcast channel place frame at superframe according to the frame number of broadcast channel place frame; And the control trapping module is caught broadcast channel in the frame that finds.
17, a kind of ofdm system comprises base station and communication terminal, it is characterized in that,
Described base station comprises:
Extraction module is used for extracting the frame number of at least one frame of superframe;
Scrambling module utilizes described frame number to synchronization channel scrambling;
Broadcast module is used for transmitting broadcasting channel at least one frame of superframe; And in the frame of described frame number correspondence the synchronizing channel of transmission after the scrambling;
Described communication terminal comprises:
Memory module is used for the frame number of recorded announce channel place frame;
Trapping module is used for catching the synchronizing channel that the base station broadcast module is transmitted;
Descrambling module is used for the synchronizing channel that captures is carried out descrambling, obtains the current frame number of this synchronizing channel place frame;
The broadcast channel that described trapping module is caught broadcast module transmission in the base station according to the frame number and the current frame number of broadcast channel place frame.
18, ofdm system according to claim 17 is characterized in that, described base station also comprises conversion module, is used for the synchronizing channel after the scrambling is carried out discrete Fourier transform (DFT).
19, ofdm system according to claim 17 is characterized in that, described communication terminal also comprises inverse transform block, is used for the synchronizing channel that captures is carried out anti-discrete Fourier transform (DFT), and outputs to descrambling module.
20, ofdm system according to claim 17 is characterized in that, described communication terminal also comprises:
Comparison module is used for the frame number of more current frame number and broadcast channel place frame, and when the frame number of current frame number and broadcast channel place frame was identical, the control trapping module was caught broadcast channel in the frame of current frame number correspondence.
21, ofdm system according to claim 17 is characterized in that, described communication terminal also comprises:
Locating module is used for determining according to current frame number and frame length the frame number of superframe boundaries and each frame of superframe;
Search module, be used for searching broadcast channel place frame at superframe according to the frame number of broadcast channel place frame; And the control trapping module is caught broadcast channel in the frame that finds.
22, base station according to claim 17 is characterized in that, described synchronizing channel is primary synchronization channel or auxiliary synchronization channel; Described frame number is represented by the low level of the corresponding binary number of frame number.
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| CNA2008100007433A CN101488931A (en) | 2008-01-15 | 2008-01-15 | Transmitting, capturing method for OFDM, device and system therefor |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108282266A (en) * | 2018-01-22 | 2018-07-13 | 福建飞通通讯科技股份有限公司 | Audio signal processing method, apparatus and system |
| CN114374932A (en) * | 2020-10-14 | 2022-04-19 | 北京紫光展锐通信技术有限公司 | Wireless communication method and device, terminal and management equipment |
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2008
- 2008-01-15 CN CNA2008100007433A patent/CN101488931A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108282266A (en) * | 2018-01-22 | 2018-07-13 | 福建飞通通讯科技股份有限公司 | Audio signal processing method, apparatus and system |
| CN114374932A (en) * | 2020-10-14 | 2022-04-19 | 北京紫光展锐通信技术有限公司 | Wireless communication method and device, terminal and management equipment |
| CN114374932B (en) * | 2020-10-14 | 2023-06-06 | 北京紫光展锐通信技术有限公司 | Wireless communication method and device, terminal and management equipment |
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