CN101425846A - Synchronous burst timing based on beacon frame structure and sequence number detection method and apparatus - Google Patents
Synchronous burst timing based on beacon frame structure and sequence number detection method and apparatus Download PDFInfo
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Abstract
The invention relates to a synchronous abrupt timing and synchronous sequence code detection method based on a beacon frame. Based on the invention and that the time required by a communication system (i.e. WRAN) recognizing the radio is not longer than that of the synchronous abrupt timing and synchronous sequence code detection in the common time slot (1-30), the time of the beacon detection always satisfies the requirement of a WRAN system in an in-frame or inter-frame condition.
Description
Technical field
The present invention relates to field of wireless communications systems, particularly in the wireless zone system (wireless regional access network) and other is based on how carrying out synchronization burst in the IEEE802.22.1 beacon system in the communication system of cognitive radio technology regularly and the method that detects the corresponding synchronous sequence number based on cognitive radio.
Background technology
Present IEEE802.22 with and under relevant communication standard and relevant documentation such as TG802.22.1 in, do not point out how to utilize the communication between devices cycle to carry out synchronization burst regularly and the detection of corresponding sequence number.
Along with the appearance of the cognitive radio technology of using based on dynamic spectrum and unlicensed band equipment, also increase day by day for the demand of rapid and reliable radio control channel.This type of control channel can be created by utilizing wireless beacon (beacon).Most typical requirement for these beacons is that beacon must be very strong to various wireless channel performances.In addition, for fear of the interference to authorized wireless devices and other unauthorized wireless device, beacon must be very short, and transmitting power is very low.Beacon in the IEEE802.22.1 standard is exactly a kind of typical beacon that satisfies above condition.Usually, in the IEEE802.22.1 agreement, two class beacon transmitting apparatus are arranged, be referred to as optimum beacon transmitting apparatus (PPD) and suboptimum beacon transmitting apparatus (SPD) respectively.PPD has the control leading role that whole beacon is sent.Therefore, in most cases, the peripherad SPD of PPD and based on the network of cognitive radio (for example: each client device in the wireless zone Access Network (WRAN) (CPE:Consumer Premise Equipment) sends beacon.At some particular time-slot, thus SPD need discontinuously to PPD send that bootstrap information helps that PPD merges that complete channel that all bootstrap informations form accumulation occupies and geographical position or the like information broadcast to each CPE.
Fig. 1 has provided the superframe structure that comprises the communication between devices time slot in the IEEE802.22.1D2 agreement.A superframe 101 is made of 31 time slots.Each time slot comprises 32 DQPSK symbols.The 1-30 of superframe common time slot is made up of two parallel logic channels.First logic channel is a synchronizing channel 102.Second logic channel is beacon channel 103.Synchronizing channel 103 is made of a series of synchronization burst.This superframe also comprises a special time slot (time slot O), this time slot carries out section two-way time (turnaround time) of Code And Decode by enough PPD and SPD, receiving cycle RTS (Request To Send) 104 and carry out the ANP cycles (Acknowledgement/No Acknowledgement Period) 105 that ACK/NACK sends and form.In the RTS cycle 104, the beacon that PPD monitors from each SPD of cycle sends solicited message; In the ANP cycle 105, whether PPD broadcasts its decision to each SPD decision and is sent beacon information and which SPD to be sent beacon by by SPD.
When (for example: when WRAN) needing work, at first equipment such as CPE in the system and base station BS all need to carry out frequency spectrum perception based on the wireless cordless communication network of understanding.And for the authorized frequency bands low power consuming devices that works in the TV broadcast band that is subjected to IEEE802.22.1beacon protection, thereby equipment such as CPE in the cordless communication network and BS need correct these beacon signals that receive to draw channel that complete authorized user works and geographical position or the like useful information.
Just as described in Figure 1, a Beacon frame is made of jointly synchronizing channel and beacon channel.Synchronizing channel and beacon channel send on the I of physical channel channel and Q channel respectively.
Fig. 2 go out in the modulation function block diagram of beacon equipment transmitting terminal.
Each Bit data among synchronization burst (I channel) and the beacon PPDU (Q channel) at first passes through I channel and the Q channel of logic to physical mappings to physical channel; After differential QPSK (DQPSK) modulation, form modulation symbol then; Each DQPSK modulation symbol is washed into mode filter and is modulated on each carrier wave and forms modulation signal through forming chip and passages through which vital energy circulates behind the pseudo random sequence spread spectrum.
Therefore, CPE in the cordless communication network and BS are for the correct beacon information that receives, need at first to receiving and carrying out synchronization burst (I channel) through the base band beacon signal behind the filter and regularly detect and the corresponding synchronous sequence number detection, thereby thereby the original position of knowing this asynchronous detection frame is further passed through corresponding demodulation, and steps such as decoding obtain corresponding bit information in the beacon channel (Q channel).
Fig. 3 (a) has provided the structure of each synchronization burst on the I channel among the IEEE802.22.1D2.Each synchronization burst is made of four part territories: 15 bit synchronous territories, and 7 bit synchronous sequence number territories, 8 bit verification territories and 2 bits keep the territory.For for the wireless receiver of WRAN system, this wireless receiver should be able to successfully be caught synchronization burst and corresponding synchronous sequence number.When being given in induction (sensing) window respectively and crossing over several continuous common time slots, Fig. 3 (b) and Fig. 3 (c) successfully catch the example of synchronization burst and corresponding synchronous sequence number under two kinds of worst conditions.Among Fig. 3 (b), the induction window begins to catch from second bit of synchronization field, therefore thereby the frequency expansion sequence of separating of receiving terminal needs continuous 47 the DQPSK modulation symbols of reception that slide can successfully obtain SYN territory, the synchronization field of verification territory and next synchronization burst.Among Fig. 3 (c), the sensing window begins to catch from second bit in SYN territory, therefore thereby the frequency expansion sequence of separating of receiving terminal needs 47 synchronization field, SYN territory and the verification territories that the DQPSK modulation symbol can successfully obtain next synchronization burst of reception of sliding continuously.Need the information of previous symbol and pulse shaping filter also to agree to have the requirement of certain rolloff-factor and WRAN system so consider the DQPSK symbol demodulation for the beacon signal detection time, the size of sensing window is decided to be 49 symbols (for example: symbol rate is 9.6091kbaud in the WRAN system, and the size that therefore is used for the induction window of synchronization burst timing and SYN detection is 49/9.6091=5.1ms).
For each beacon frame, at the 31st time slot, PPD or SPD forbid sending the beacon signal and are placed in the communication between devices cycle but as shown in Figure 1.Shown in Fig. 4 (a), this time slot still is made of 32 symbols: 1-5 symbol is two-way time, and 6-13 symbol is the RTS cycle, and 14-19 symbol is two-way time, and 20-27 symbol is the ANP cycle, and 28-32 symbol is two-way time.Wherein, the RTS cycle is used for each and wishes that the SPD that sends the beacon signal sends solicited message to PPD, perhaps sends information to confirm that NPD still is in active state by NPD (next-in-line protecting device) to PPD; The ANP cycle is used for PPD the solicited message of receiving in the cycle at RTS is responded.
So, when beginning to carry out synchronization burst from the 2nd bit of the 30th time slot of beacon frame or bit thereafter, the WRAN receiver regularly detects, then shown in Fig. 4 (b), in order successfully to catch 7 bit synchronous sequence number territories of the 30th time slot, the synchronization field of first time slot of 8 bit verification territories and next beacon frame, then the length of the needed induction window of WRAN receiver will can reach 81 symbols (being 8.42ms) for extreme case considerably beyond 49 symbols; Similarly, when beginning to carry out synchronization burst from the 17th bit (being the 2nd bit in SYN territory) of the 30th time slot of beacon frame, the WRAN receiver regularly detects, then shown in Fig. 4 (c), in order successfully to catch the synchronization field of first time slot of next beacon frame, SYN territory and verification territory, then the length of the needed induction window of WRAN receiver also will also reach 81 symbols for extreme case considerably beyond 49 symbols.In addition, when communication cycle between WRAN receiver slave unit (i.e. the 31st time slot) begins to carry out synchronization burst when regularly detecting, also be difficult to usually satisfy successfully realize in 49 symbols synchronization burst regularly and SYN detect.
Above situation be based on cognitive radio cordless communication network (such as: WRAN) institute unallowable.
Summary of the invention
The purpose of this invention is to provide the two-way time in a kind of communication between devices cycle (being the 31st time slot of each beacon frame) of the IEEE802.22.1beacon of making full use of frame, signal message, silence period and other the common synchronization burst that sends in RTS cycle and ANP cycle carry out effectively jointly synchronization burst regularly and SYN detect.
For achieving the above object, a kind of synchronization burst timing and SYN detection method based on beacon frame structure comprise:
A) wireless communication system receiver based on cognitive radio receives from the beacon beacon signal based on the IEEE802.22.1 system;
B) the beacon signal of the sensitive time intercepting respective length that sets according to system of receiver;
C) the beacon signal to intercepting detects and symbol sebolic addressing before the demodulation or the bit sequence after the demodulation is carried out timing analysis, determine by communication between devices time slot in the beacon signal of intercepting or common synchronization burst time slot carry out synchronization burst regularly and SYN detect;
D) carry out the time slot type detection;
E) if communication time slot between selected equipment then is provided with according to the relevant information in silence period in the devices communicating time slot, RTS, ANP and the common synchronization burst time slot adjacent with this communication between devices time slot and the symbol sebolic addressing before the demodulation or the bit sequence after the demodulation are carried out current SYN detects and carry out synchronization burst regularly;
F), then detect and realize synchronization burst regularly, and detect the SYN territory and then obtain current SYN by the synchronizing sequence in the bit sequence of described receiver after to demodulation in the synchronization burst time slot if choose common synchronization burst time slot.
Based on the present invention, based on the communication system (as: WRAN) of cognitive radio only need with common time slot (1-30) thus in synchronization burst regularly and SYN time of detecting the identical time or still less making the beacon detection in the beacon frame or interframe satisfy the demand of WRAN system always.
Description of drawings
Fig. 1 shows the beacon superframe structure schematic diagram that comprises the communication between devices time slot in the IEEE802.22.1D2.0 draft standard;
Fig. 2 shows the modulation function block diagram of IEEE802.22.1beacon equipment transmitting terminal;
Fig. 3 comprises three width of cloth figure, wherein the structure of each synchronization burst on the I channel among Fig. 3 (a) demonstration IEEE802.22.1D2; Fig. 3 (b) shows when induction (sensing) window is crossed over several continuous common time slots and successfully catches one of example of synchronization burst and corresponding synchronous sequence number under two kinds of worst conditions; Fig. 3 (c) shows when induction (sensing) window is crossed over several continuous common time slots two of the example of successfully catching synchronization burst and corresponding synchronous sequence number under two kinds of worst conditions;
Fig. 4 comprises three width of cloth figure, and wherein Fig. 4 (a) shows each symbol division schematic diagram in the special communication between devices cycle time slot; When showing between induction (sensing) window line balance converter communication time slot, Fig. 4 (b) successfully catches one of time (not adopting the present invention) example of synchronization burst and corresponding synchronous sequence number under two kinds of worst conditions; Successfully catch under two kinds of worst conditions when Fig. 4 (c) shows communication time slot between induction (sensing) window line balance converter synchronization burst and corresponding synchronous sequence number time (not adopting the present invention) example two;
Fig. 5 demonstration is carried out synchronization burst timing and SYN testing process figure based on receiver of the present invention;
Fig. 6 comprises two width of cloth figure, and wherein Fig. 6 (a) shows the block diagram (timing analysis is finished) that carries out synchronization burst timing and SYN detection based on receiver of the present invention after the DQPSK demodulation; Fig. 6 (b) shows the block diagram (timing analysis is finished) that carries out synchronization burst timing and SYN detection based on receiver of the present invention before the DQPSK demodulation.
Embodiment
Fig. 5 according to the wireless communication system based on cognitive radio of the present invention (for example: WRAN) carry out synchronization burst regularly and the flow chart of SYN detection method has provided.According to Fig. 5, as follows based on the step that the synchronization burst timing and the SYN of IEEE802.22.1beacon signal are detected of the present invention:
1. be in the data of normal condition transmitting-receiving communication system inside based on receiving equipment (for example: BS in the WRAN system or CPE) in the wireless wireless communication system of understanding;
2. the cycle of carrying out is the synchronization burst sensing of 5.1ms;
3., then carry out relevant with the sliding window that the PN frequency expansion sequence forms if based on receiving equipment in the wireless wireless communication system of understanding the beacon channel is carried out the threshold value that energy measuring reaches defined; If the beacon channel is carried out the threshold value that energy measuring does not reach defined, then restarting another cycle is the synchronization burst sensing window of 5.1ms;
4. correlated results is carried out integration and sample with the DQPSK character rate;
5., then form all 48 continuous DQPSK symbol sebolic addressings if successfully sampling obtains all effective DQPSK symbols; If it is less significant symbols that part DQPSK symbol is arranged, then prove and in these 48 symbol periods, have at least one symbol period of mourning in silence, therefore at first state to have at least one symbol and form 48 DQPSK symbol sebolic addressings of mourning in silence in these 48 symbol periods, comprising the symbol of mourning in silence;
6. carry out the time slot type detection.It is common time slot (1-30) or communication between devices cycle time slot (0 time slot or be referred to as the RTS/ANP time slot) by the sensing window capture that its effect is mainly used in detection.Below with regard to time slot type detection (a) after the DQPSK demodulation is carried out or (b) carries out subsequent step respectively before the DQPSK demodulation description:
● if the time slot type detection is for carrying out (a) after the DQPSK demodulation
7.DQPSK demodulation obtains hard bit information and silence period judgement VB vacancy bit position information;
8. determine that this sensing window is positioned at the time slot of which kind of type thereby bit information and silence period judgement VB vacancy bit position information is carried out timing analysis, and by the particular location to the analysis and judgement communication between devices cycle time slot of silence period discriminative information.Such as: the sensing window is positioned at common time slot fully, and perhaps part is positioned at common time slot, and part is positioned at the communication between devices time slot, and communication between devices time slot residing position in the sensing window is at front end, centre or rear end;
9. judge that whether leading at that time time slot type is communication between devices time slot (just time slot 0 or be referred to as the RTS/ANP time slot);
10. if leading at that time time slot type is not the communication between devices time slot, determine that the starting point of synchronization field in the synchronization burst carries out synchronization burst regularly thereby then the bit information after the DQPSK demodulation and 15 bit m-sequences are carried out coherent detection, then SYN is deciphered detection; If it is correct that SYN decoding detects, then carry out the detection of TG1 frame synchronization and beacon information.
11. if leading at that time time slot type is the communication between devices time slot, whether the communication cycle time slot is positioned at the end of sequence between then further judgment device.If be positioned at the end of sequence, current SYN Index=0 then be set, and carry out the detection of TG1 frame synchronization and beacon information; If be positioned at the middle-end or the front end of sequence, current SYN Index=30 then be set and carry out TG1 frame synchronization and the detection of beacon information.
● if the time slot type detection is for carrying out (b) before the DQPSK demodulation
7. to including the DQPSK symbol and thereby the sequence of symbol period of mourning in silence is carried out timing analysis and determined that this sensing window is positioned at the time slot of which kind of type, and by particular location to the analysis and judgement communication between devices cycle time slot of the symbol period of mourning in silence;
8. judge that whether current leading time slot type is communication between devices time slot (just time slot O or be referred to as the RTS/ANP time slot);
9., then at first carry out the DQPSK demodulation and obtain hard bit information and silence period discriminative information if leading at that time time slot type is not the communication between devices time slot.Determine that the starting point of synchronization field in the synchronization burst carries out synchronization burst regularly thereby the bit information after the DQPSK demodulation and 15 bit m-sequences are carried out coherent detection, then SYN is deciphered detection; If it is correct that SYN decoding detects, then carry out the detection of TG1 frame synchronization and beacon information.
10. if leading at that time time slot type is the communication between devices time slot, whether the communication cycle time slot is positioned at the end of sequence between then further judgment device.If be positioned at the end of sequence, current SYN Index=0 then be set, and carry out the detection of TG1 frame synchronization and beacon information; If be positioned at the middle-end or the front end of sequence, current SYN Index=30 then be set and carry out TG1 frame synchronization and the detection of beacon information.
The method flow chart is sent out in invention according to above-mentioned invention formation and Fig. 5, Fig. 6 (a) and Fig. 6 (b) provided respectively the timing analysis module be positioned at after the DQPSK demodulation and the wireless communication system before the DQPSK demodulation based on cognitive radio (for example: WRAN) carry out synchronization burst regularly and the block diagram of SYN detection reception.
In Fig. 6 (a), mainly comprise: signal intercepting trapping module; Energy measuring and filtering shaping module; The pseudo random sequence generation module; The Direct Sequence Spread Spectrum Signal detection module; The timing synchronization module, the symbol sampler module; The timing analysis module; The DQPSK demodulation module; Synchronization burst is detection module regularly; SYN decoding detection module.
Wherein:
1. signal intercepting trapping module (for example: WRAN) utilize the sensing window of specific length to intercept corresponding beacon signal and be used for synchronization burst regularly and the SYN detection is mainly used in wireless communication system based on cognitive radio.In at present corresponding open debate of WRAN and respective document, the length that the sensing window is set is 5.1ms;
2. thereby energy measuring and filtering shaping module are mainly used in the beacon signal energy that detects intercepting and whether meet the requirements of thresholding and judged whether beacon information, and are shaped by filtering and form the chip samples that can be used for Base-Band Processing;
3. the pseudo random sequence generation module is mainly used in and generates local pseudo random sequence and be used to carry out the spread-spectrum signal despreading and detect;
4. the Direct Sequence Spread Spectrum Signal detection module is mainly used in the base-band spread-spectrum signal that receives is carried out relevant and carry out integration obtaining corresponding relevant peaks with the pseudo random sequence that the pseudo random sequence generation module produces;
5. thereby the timing synchronization module is mainly used in and produces the sampled point that the symbol timing base can obtain each modulation symbol;
6. the symbol sampler module is mainly used in the symbol sampler value that obtains each DQPSK modulation symbol under the cooperation of timing synchronization module;
Thereby the symbol sampler value of DQPSK modulation symbol is carried out demodulation acquisition bit information 7.DQPSK demodulation module is mainly used in; If comprise the time slot (time slot 0 that partly or entirely is used for communication between devices in the sensing window, or be referred to as the RTS/ANP time slot), then not only comprise hard bit decision information, also comprise some silence period discriminative informations in addition through output information behind the DQPSK demodulation module.Therefore the sequence through the output of DQPSK demodulation module has following form:
1011EEEEEEEEEE10110001011001...；
In above-mentioned sequence " E " existence be because following reason: if the beacon signal that intercepts in the sensing window has part or is positioned at the communication between devices cycle (time slot O, or be referred to as the RTS/ANP time slot), then silence period may appear.In this communication between devices time slot, have 16 symbol periods and be used for two-way time (turnaround time), shown in Fig. 4 (a).And in silence period, PPD or SPD do not send any data, therefore (for example: receiver WRAN) can't detect any useful information based on the wireless communication system of cognitive radio, thereby through occurring after the DQPSK demodulation " E " symbolic representation silence period discriminative information---the VB vacancy bit position (concrete decision criteria is looked each receiving system, but with regard to court verdict with common " 0 " bit and " 1 " bit information has evident difference).Therefore, can comprise following three kinds of silence period judgement VB vacancy bit position information in the sequence through the output of DQPSK demodulation module:
1) first silence period is ending and 5 sign bits of RTS between the cycle at time slot 1.Therefore, under this kind situation, can comprise continuous 10 in the sequence through the output of DQPSK demodulation module " E ";
2) second silence period is 6 sign bits between the cycle in RTS cycle and ANP.Therefore, under this kind situation, can comprise continuous 12 in the sequence through the output of DQPSK demodulation module " E ";
3) the 3rd silence period is at 5 sign bits between the time slot 30 of ANP cycle and next beacon frame initial.Therefore, under this kind situation, can comprise continuous 10 in the sequence through the output of DQPSK demodulation module " E ".
In addition, also have a kind of special circumstances when receiver designs, to need to consider.Under normal conditions, RTS has at least one SPD and sends the RTS solicited message to PPD in the cycle.But in some time period, RTS also can occur in the cycle sending the RTS solicited message without any SPD.So, under this kind situation, long silence period after first silence period and RTS cycle and second the common shape of silence period, we are referred to as the 4th silence period for the time being, through therefore comprising continuous 38 in the sequence of DQPSK demodulation module output " E ".
8. timing analysis module functions is by the difference in length of analyzing the silence period judgement VB vacancy bit position information in the sequence of DPQSK demodulation module output and the difference of front and back bit information, and then judge the residing time slot type of sensing window, communication between devices time slot residing position or the like in whole receiving sequence is various to be helped follow-uply carrying out that synchronization burst detects and the information of SYN detection.Its main analytic function is exemplified below (concrete bit distribution is referring to Fig. 4 (b) and Fig. 4 (c)):
If do not comprise any silence period judgement VB vacancy bit position information in a all sequences, prove that then all beacon signals that the sensing window is intercepted only are positioned at common time slot district (time slot 1-30);
If the b information of mourning in silence is in the latter half of sequence, the beacon signal that then proves sensing window intercepting is positioned at common time slot district and communication between devices time slot (time slot 2 and (or) time slot 1, and time slot 0);
If the c information of mourning in silence is in the first half of sequence, prove that then the beacon signal of sensing window intercepting is positioned at the common time slot district of communication between devices time slot and next beacon frame (time slot 0, next frame time slot 30 and (or) time slot 29);
If the d information of mourning in silence is in the mid portion of sequence, prove that then the beacon signal of sensing window intercepting is positioned at the common time slot district of this beacon frame, the common time slot district of communication between devices time slot and next beacon frame (time slot 1, time slot 0 and next frame time slot 30);
Situation to b, c and d three kinds of common time slots district and the coexistence of O time slot district, the timing analysis module needs further to analyze determine leading time slot type, and regularly detection module and SYN decoding detection module carry out according to leading time slot type that synchronization burst regularly detects and SYN decoding detects thereby judge follow-up synchronization burst.
1) for b kind situation, when silence period judgement drew sequence after the DQPSK demodulation and is made of complete time slot 1 and part time slot O, then the leading time slot type of proof was common time slot; When sequence was made of complete time slot 1 and part time slot 2 and part time slot 0, then the leading time slot type of proof was common time slot; When sequence is made of incomplete time slot 1 and part time slot 0 (herein, incomplete time slot is defined as and can not comprises 15 bit synchronous territories simultaneously, 7 bit synchronous sequence number territories and 8 bit verification territories), then the leading time slot type of proof is the communication between devices time slot;
2) for c kind situation, when silence period judgement drew sequence after the DQPSK demodulation and is made of next complete beacon frame slot 30 and part present frame time slot 0, then the leading time slot type of proof was common time slot; When sequence by complete next frame time slot 30 and part time slot 29 with when time frame part time slot 0 constitutes, then the leading time slot type of proof is common time slot; When sequence is made of incomplete next beacon frame slot 30 and part current time slots 0 (herein, incomplete time slot is defined as and can not comprises 15 bit synchronous territories simultaneously, 7 bit synchronous sequence number territories and 8 bit verification territories), then the leading time slot type of proof is the communication between devices time slot;
3) for d kind situation, because the information of mourning in silence is in the mid portion of sequence, then because time slot 0 has occupied most sensing time, therefore the time slot 1 of current beacon frame and time slot 30 necessity of next frame are imperfect time slot, and then the leading time slot type of proof is the communication between devices time slot.
Thereby synchronization burst regularly detection module be mainly used in reception and whether adopt synchronization burst regularly to detect from the information and the decision of the sequence after the DQPSK demodulation of timing analysis module.If leading time slot is common time slot, then with 15 bit m-sequences (the different respective change that take place of sequence generating mode that concrete sequence type adopts with synchronization field in the beacon frame); If leading time slot is the communication between devices time slot, then the result by timing analysis can judge the corresponding synchronous burst regularly easily;
10. SYN is deciphered detection module mainly with the living information that receives from the timing analysis module, deciphers detection thereby the information of synchronization burst timing detection module and the sequence after the DQPSK demodulation determine whether to adopt the decoding detection mode that the SYN territory is reached relevant verification territory.If leading time slot is common time slot, then by synchronization burst regularly the output of detection module determine the SYN territory in the sequence after the DQPSK demodulation and the position in corresponding verification territory, and by its decoding is detected, whether the sequence number (Index) of judging gained is correctly and export correct SYN.It should be noted that here that if carry out synchronization field that synchronization burst adopts regularly the time with the SYN territory when inconsistent synchronization burst sequence number in the time of should adjusting the output result this is ended up with current induction window is consistent; If leading time slot is the communication between devices time slot, then the result according to timing analysis judges whether this communication between devices time slot is positioned at the end of sequence.If be positioned at end, it is 0 also output that SYN then is set; If the communication between devices time slot is positioned at middle or front end, it is 30 also outputs that SYN then is set;
11. based on the wireless communication system of cognitive radio (for example: WRAN) after through synchronization burst detection module and SYN decoding detection module, will be regularly and the SYN result be used to carry out follow-up TG1 frame synchronization and beacon information detects the synchronization burst of gained.
Below illustrated for example after the timing analysis module is positioned at the DQPSK demodulation module, below Fig. 6 (b) in provide when the timing analysis module is positioned at before the DQPSK demodulation module, based on the wireless communication system of cognitive radio (for example: WRAN) carry out synchronization burst regularly and SYN detect the block diagram of reception.
In Fig. 6 (b), mainly comprise: signal intercepting trapping module; Energy measuring and filtering shaping module; The pseudo random sequence generation module; The Direct Sequence Spread Spectrum Signal detection module; The timing synchronization module, the symbol sampler module; The timing analysis module; The DQPSK demodulation module; Synchronization burst is detection module regularly; SYN decoding detection module.Wherein remove timing analysis the module function and middle describe consistent of Fig. 6 (a) of other all modules later on.Therefore, timing analysis module functions in the details drawing 6 (b) below.Other functions of modules are with reference to top description to Fig. 6 (a).
1. timing analysis module functions is by analyzing through the difference in length of the silence period symbol in the not demodulation DPQSK symbol sebolic addressing after the symbol sampler module and the difference of front and back symbolic information, and then judge the residing time slot type of sensing window, communication between devices time slot residing position or the like in whole receiving symbol sequence is various to be helped follow-uply carrying out that synchronization burst detects and the information of SYN detection.Its main analytic function is exemplified below (specifically distributing referring to Fig. 4 (b) and Fig. 4 (c)):
If do not comprise any silence period symbolic information in all symbol sebolic addressings of a, prove that then all beacon signals that the sensing window is intercepted only are positioned at common time slot district (time slot 1-30);
If the b information of mourning in silence is in the latter half of symbol sebolic addressing, the beacon signal that then proves sensing window intercepting is positioned at common time slot district and communication between devices time slot (time slot 2 and (or) time slot 1, and time slot 0);
If the c information of mourning in silence is in the first half of symbol sebolic addressing, prove that then the beacon signal of sensing window intercepting is positioned at the common time slot district of communication between devices time slot and next beacon frame (time slot 0, next frame time slot 30 and (or) time slot 29);
If the d information of mourning in silence is in the mid portion of symbol sebolic addressing, prove that then the beacon signal of sensing window intercepting is positioned at the common time slot district of this beacon frame, the common time slot district of communication between devices time slot and next beacon frame (time slot 1, time slot 0 and next frame time slot 30);
Situation to b, c and d three kinds of common time slots district and the coexistence of 0 time slot district, the timing analysis module needs further to analyze determine leading time slot type, and regularly detection module and SYN decoding detection module carry out according to leading time slot type that synchronization burst regularly detects and SYN decoding detects thereby judge follow-up synchronization burst.
1) for b kind situation, when the silence period symbol judgement drew the DQPSK modulation symbol sequence and is made of complete time slot 1 and part time slot 0, then the leading time slot type of proof was common time slot; When sequence was made of complete time slot 1 and part time slot 2 and part time slot 0, then the leading time slot type of proof was common time slot; When sequence is made of incomplete time slot 1 and part time slot 0 (herein, incomplete time slot is defined as and can not comprises 15 bit synchronous territories simultaneously, 7 bit synchronous sequence number territories and 8 bit verification territories), then the leading time slot type of proof is the communication between devices time slot;
2) for c kind situation, when the silence period symbol judgement drew the DQPSK modulation symbol sequence and is made of next complete beacon frame slot 30 and part present frame time slot 0, then the leading time slot type of proof was common time slot; When sequence by complete next frame time slot 30 and part time slot 29 with when time frame part time slot O constitutes, then the leading time slot type of proof is common time slot; When sequence is made of incomplete next beacon frame slot 30 and part current time slots 0 (herein, incomplete time slot is defined as and can not comprises 15 bit synchronous territories simultaneously, 7 bit synchronous sequence number territories and 8 bit verification territories), then the leading time slot type of proof is the communication between devices time slot;
3) for d kind situation, because the information of mourning in silence is in the mid portion of sequence, then because time slot 0 has occupied most sensing time, therefore the time slot 1 of current beacon frame and time slot 30 necessity of next frame are imperfect time slot, and then the leading time slot type of proof is the communication between devices time slot.
Except that above embodiment, under the requirement of certain receiver device complexity allows, thereby the joint-detection that can also be correlated with improves the reliability that detects.If current leading time slot is common time slot, also can be by to the silence period of communication between devices time slot, thus RTS and ANP relevant information detect checking whether with carried out the result that synchronization burst regularly detects and SYN detects by common time slot consistent; Equally, if current leading time slot is the communication between devices time slot, thus also can whether consistent by judged result is detected in the synchronization field information that exists in the incomplete common time slot or SYN territory.
Claims (9)
- One kind based on the synchronization burst of beacon frame structure regularly and the SYN detection method, comprising:A) wireless communication system receiver based on cognitive radio receives from the beacon beacon signal based on the IEEE802.22.1 system;B) the beacon signal of the sensitive time intercepting respective length that sets according to system of receiver;C) the beacon signal to intercepting detects and symbol sebolic addressing before the demodulation or the bit sequence after the demodulation is carried out timing analysis, determine by communication between devices time slot in the beacon signal of intercepting or common synchronization burst time slot carry out synchronization burst regularly and SYN detect;D) carry out the time slot type detection;E) if communication time slot between selected equipment then is provided with according to the relevant information in silence period in the devices communicating time slot, RTS, ANP and the common synchronization burst time slot adjacent with this communication between devices time slot and the symbol sebolic addressing before the demodulation or the bit sequence after the demodulation are carried out current SYN detects and carry out synchronization burst regularly;F), then detect and realize synchronization burst regularly, and detect the SYN territory and then obtain current SYN by the synchronizing sequence in the bit sequence of described receiver after to demodulation in the synchronization burst time slot if choose common synchronization burst time slot.
- 2. method according to claim 1 is characterized in that the beacon signal to intercepting in the described step c) detects and comprises:If the beacon channel is carried out the energy value that energy measuring reaches defined, then the sliding window with the formation of PN frequency expansion sequence is relevant;Correlated results is carried out integration and samples with the DQPSK character rate;If successfully sampling obtains effective DQPSK symbol, then form all 48 continuous DQPSK symbol sebolic addressings.
- 3. method according to claim 1 is characterized in that described step d) comprises: if being the DQPSK demodulation, the time slot type detection carries out afterwards,Then the DQPSK demodulation obtains hard bit information and silence period judgement VB vacancy bit position information;Hard bit information and silence period judgement VB vacancy bit position information are carried out timing analysis, determine that the sensing window is positioned at the time slot of which kind of type and the particular location of communication between devices time slot.
- 4. method according to claim 1 is characterized in that described step d) comprises: if being the DQPSK demodulation, the time slot type detection carries out before,Then carry out timing analysis with the sequence of the symbol period of mourning in silence, determine that the sensing window is positioned at the time slot of which kind of type and the particular location of communication between devices time slot including the DQPSK symbol.
- 5. method according to claim 1 is characterized in that the bit sequence that the beacon signal to intercepting carries out after the demodulation not only comprises bit information, also comprises carrying out the formed VB vacancy bit of demodulation position information in the silence period.
- 6. method according to claim 1, it is characterized in that beacon signal to intercepting detects and the sampling symbol sebolic addressing before the demodulation or the bit sequence after the demodulation carried out timing analysis being meant the difference of the silence period length by symbol sebolic addressing before the demodulation or the bit sequence after the demodulation and the difference of front and back bit information, and then judge the residing time slot type of sensing window, communication between devices time slot residing position or the like in whole receiving sequence is various to be helped follow-uply carrying out that synchronization burst detects and the information of SYN detection.
- 7. method according to claim 1, current SYN are meant that the sensing window intercepts all SYNs of terminal residing time slot or by the convenient decision of system design.
- 8. method according to claim 1 is characterized in that described sensitive time intercepted length is 5.1 milliseconds.
- One kind be used to receive based on the IEEE802.22.1beacon signal and carry out synchronization burst regularly and the receiver that detects of SYN comprise:The signal receiving processing module is used to receive and detect the beacon signal of certain-length, wherein mainly comprises: the signal intercepting, and signal energy detects, filtering, sequence is separated spread spectrum and is detected and the symbol sampler function;Demodulation module is used for the beacon signal of signal receiving processing module output is carried out symbol demodulation;The timing analysis module, be used for the particular sequence that signal receiving processing module or demodulation module are handled out is carried out timing analysis, thereby determine that it still is common time slot that the beacon signal that is intercepted mainly is positioned at the communication between devices cycle, and the signal that is intercepted is analyzed concrete the composition;Synchronization burst is detection module regularly, is used to receive from the sequence of demodulation module output and according to the output of timing analysis module carry out the beacon frame slot regularly;SYN decoding detection module is used for detecting to the residing sequence of time slots of beacon signal at that time number.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111903095A (en) * | 2018-01-17 | 2020-11-06 | 日本电信电话株式会社 | Detection device, method thereof, and program |
| WO2022252796A1 (en) * | 2021-05-31 | 2022-12-08 | 华为技术有限公司 | Online detection method based on heartbeat packet, and device |
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2007
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111903095A (en) * | 2018-01-17 | 2020-11-06 | 日本电信电话株式会社 | Detection device, method thereof, and program |
| CN111903095B (en) * | 2018-01-17 | 2022-02-11 | 日本电信电话株式会社 | Detection device and method thereof, and recording medium |
| WO2022252796A1 (en) * | 2021-05-31 | 2022-12-08 | 华为技术有限公司 | Online detection method based on heartbeat packet, and device |
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