Summary of the invention
The technical problem that the present invention will solve is; Above-mentioned power consumption to prior art is big; And the defective of the process more complicated of particular communication equipment being controlled according to the practical communication demand; Provide a kind of wireless communication method, power consumption little, and can control particular communication equipment according to the practical communication demand.
The technical solution adopted for the present invention to solve the technical problems is: construct a kind of wireless communication method, be used for when main equipment has communication requirement, sending information to specific slave unit, this wireless communication method comprises:
S1. main equipment is according to communication requirement; By specific encoder formation sequence sign indicating number; And in Preset Time, send said sequence code continuously to each slave unit, wherein, said specific encoder is the feedback shift register that is made up by particular polynomial; And the coefficient of said particular polynomial is relevant with communication requirement with exponent number; Polynomial coefficient and initial value all are not 0 entirely, and said Preset Time is more than or equal to the rest period and detection phase sum of said slave unit, and said rest period constitutes a dormancy awakening cycle with the phase of detection sum;
S2. specific slave unit receives one section continuous in the said sequence code in the detection phase, and the use decoder corresponding with said encoder decipher this section sequence code, and operates accordingly according to decode results.
In wireless communication method of the present invention, when communication requirement was waken up for all slave units are broadcasted, the sequence code that said encoder produced was the m sequence, and each slave unit all comprises and the pairing decoder of said encoder.
In wireless communication method of the present invention; When communication requirement is waken up for the slave unit of particular group is organized; The combination of the binary system group number of the slave unit that said particular polynomial coefficient is said particular group and preset first fixed sequence program, and all comprise in the slave unit of said particular group and the pairing decoder of said encoder.
In wireless communication method of the present invention; In communication requirement is when specific slave unit is carried out single waking up; Said particular polynomial coefficient is the combination of at least a portion of binary system ID number and preset second fixed sequence program of at least a portion of binary system ID number or the said specific slave unit of said specific slave unit, and comprises in the said specific slave unit and the pairing decoder of said encoder.
In wireless communication method of the present invention; In communication requirement is during to specific slave unit sending controling instruction; Said particular polynomial coefficient is binary system ID number at least a portion of said specific slave unit and the combination of the pairing binary sequence of said control command, and comprises in the said specific slave unit and the pairing decoder of said encoder.
In wireless communication method of the present invention; When communication requirement opens or closes the valve instruction for sending to specific slave unit; Said particular polynomial coefficient is that at least a portion of binary system ID number of said specific slave unit is instructed the combination of pairing binary sequence with the preset valve that opens or closes; And pairing binary sequence is different respectively with closing the valve instruction to open the valve instruction, comprises and the pairing decoder of said encoder in the said specific slave unit simultaneously.
In wireless communication method of the present invention; After specific slave unit is using the decoder that is made up of specific feedback shift register that this section sequence code is deciphered; From the sequence code that is received, take out code element with the exponent number equal number; And the use initial value identical with the specific feedback shift register of main equipment comes the specific feedback shift register of the said specific slave unit of initialization; Baud rate according to current communication calculates the time that main equipment begins to launch said sequence code again; And calculate main equipment finishes to send sequence code in Preset Time time in time synchronously and/or again according to the time of being calculated and main equipment, and the times prior that specific slave unit sends sequence code in the end of being calculated is carried out dormancy.
In wireless communication method of the present invention; When said specific slave unit comprises at least two decoders; Said specific slave unit is after receiving said sequence code; Adopt the method for souning out to use said at least two decoders that said sequence code is deciphered successively, and operate accordingly according to decode results.
In wireless communication method of the present invention; In said step S1; After producing sequence code; To the logical zero in the sequence code or 1, carry out graceful Chester coding, non-return-to-zero coding or return-to-zero coding, in Preset Time, send the sequence code after carrying out graceful Chester coding, non-return-to-zero coding or return-to-zero coding continuously then to each slave unit.
In wireless communication method of the present invention,
The step that specific slave unit among the said step S2 carries out corresponding operating according to decode results comprises:
Number to deciphering the continuous output 0 in back is counted;
When whether the number of judging output 0 continuously surpassed preset limit value, then polynomial exponent number and the coefficient according to employed decoder carried out the operation of corresponding demand;
Perhaps
During to said sequence code negate, the step that the specific slave unit among the then said step S2 carries out corresponding operating according to decode results comprises after main equipment produces said sequence code:
Number to deciphering the continuous output 1 in back is counted;
When whether the number of judging output 1 continuously surpassed preset limit value, then polynomial exponent number and the coefficient according to employed decoder carried out the operation of corresponding demand.
In wireless communication method of the present invention,
After main equipment produces said sequence code, said sequence code carried out scrambling or when merging, the specific slave unit among the then said step S2 goes earlier to disturb or goes and merges, and deciphers and operates accordingly according to decode results.
The present invention also constructs a kind of wireless telecommunication system, comprises main equipment and at least one slave unit, and main equipment sends information to specific slave unit when communication requirement is arranged, and said main equipment comprises:
Coding unit; Be used for according to specific encoder formation sequence sign indicating number, wherein, said specific encoder is the feedback shift register that is made up by particular polynomial; And the coefficient of said particular polynomial is relevant with communication requirement with exponent number, and polynomial coefficient and initial value all are not 0 entirely;
Transmitting element is used in Preset Time sending said sequence code continuously to each slave unit, and said Preset Time more than or equal to rest period of said slave unit with survey the phase sum, said rest period constitutes a dormancy awakening cycle with the phase of detection sum;
Said specific slave unit comprises:
Receiving element is used for receiving said sequence code in the detection phase;
Decoding unit is used to use the decoder corresponding with said encoder that said sequence code is deciphered;
Control unit is used for operating accordingly according to decode results.
The technical scheme of embodiment of the present invention has following beneficial effect: need not synchronous in time between the Wireless Telecom Equipment of participating in communicating by letter; Antijamming capability is strong, has solved the problem of identification and false wake-up, has improved reliability and confidentiality; Can shorten the detection phase of slave unit, reduce the slave unit receive window time, thereby reduce the power consumption of communication system.
Embodiment
In the flow chart of wireless communication method embodiment one of the present invention as shown in Figure 1, this wireless communication method is used for when main equipment has communication requirement, sending information to specific slave unit, and it specifically comprises:
S1. main equipment is according to communication requirement; By specific encoder formation sequence sign indicating number; And in Preset Time, send said sequence code continuously to each slave unit, wherein, said specific encoder is the feedback shift register that is made up by particular polynomial; And the coefficient of said particular polynomial is relevant with communication requirement with exponent number; Polynomial coefficient and initial value all are not 0 entirely, and said Preset Time is more than or equal to the rest period and detection phase sum of said slave unit, and said rest period constitutes a dormancy awakening cycle with the phase of detection sum;
S2. specific slave unit receives one section continuous in the said sequence code in the detection phase, and the use decoder corresponding with said encoder decipher this section sequence code, and operates accordingly according to decode results.
Be example with linear feedback shift register as encoder and decoder below; Specify the operation principle of this wireless communication method; What need statement is that the use nonlinear feedback shift register also belongs within the scope of the present invention as encoder and decoder.
Usually, exponent number is n polynomial repressentation is following:
f(x)=c
0+c
1x+c
2x
2+...+c
nx
n (1)
X in the formula
iOnly indicate its coefficient (1 or 0) and represent c
iValue, itself does not have practical significance x, does not need to calculate yet.Its coefficient and exponent number are then extremely important, are to accomplish important parameter of the present invention.
The encoder that main equipment constitutes through the multinomial of selecting different coefficients or exponent number for use, the sequence code of generation sends to slave unit, and it represents different implications.Slave unit receives one section continuous in the said sequence code in the detection phase; And use one or more relevant decoders that said sequence code is carried out one or many decoding; If judgement is relevant after using certain decoder; Then slave unit is waken up, and according to the coefficient and the exponent number of this decoder, operates accordingly.Be the sequence code that main equipment generates, when waking slave unit up, also carry information.According to these information, slave unit can be accomplished corresponding operation.Like this, not only reduce power consumption, and improved communication efficiency.
At first; In main equipment; Main equipment is according to communication requirement, and by specific encoder formation sequence sign indicating number, this specific encoder is the feedback shift register that is made up by particular polynomial; And the coefficient of said particular polynomial is relevant with communication requirement with exponent number, polynomial coefficient be not entirely 0 and initial value be not 0 entirely yet.Formula (1) combines feedback shift register structure in the main equipment shown in Figure 2, can be characterized by:
In the formula:
Expression mould 2 adds or XOR, and n is the rank of feedback shift register, and this polynomial coefficient c
0=1, c
1, c
2... c
nCan not all be 0, and a
0, a
1... a
N-1Initial value can not all be 0, this polynomial coefficient c
1, c
2... c
nRelevant with communication requirement with exponent number n, also promptly, the coefficient or the exponent number of the employed feedback shift register of different communication requirements (encoder) are inequality.
In addition, the right-hand component of formula (2) equal sign is all moved on to the left side, distortion can get:
Can obtain the feedback shift register of a new tape input according to formula (3), as shown in Figure 3, if the coefficient c of the proper polynomial of this feedback shift register and feedback shift register shown in Figure 2
0, c
1, c
2... c
nIdentical, exponent number n is also identical, then as this feedback shift register input a
nThe time, no matter its initial value is any value, when displacement n time, all irrelevant initial values in this feedback shift register are removed after (also can use preceding n correct code element, directly initialization shift register receiving), then later displacement, it exports perseverance is 0.Like this, one section sufficiently long sequence code that slave unit will receive, be input to decoder after, after abundant continuous 0 value of output, the code element that decidable receives has correlation, is the main equipment emission, this process is the judgement correlation.
Therefore, from formula (2), can find out, be the feedback shift register of n for exponent number, and its coefficient has 2
nFollow the example of for-a kind.When the n value was enough big, following the example of of its coefficient was then abundant, like this, just for the main equipment of low-consumption wireless communication system more optional multinomial and encoder is provided.Main equipment according to the communication needs, is selected specific multinomial before initiating communication, certainly, this polynomial coefficient and exponent number and slave unit have had agreement in advance.
For the decoder of employing formula (3) in the slave unit, as long as its coefficient and exponent number just can be judged the correlation of a segment information of reception the same with the main equipment use.But if main equipment only adopts a kind of multinomial, then slave unit can use corresponding a kind of decoder for decoding to get final product.If main equipment adopts a plurality of multinomials, then slave unit is because before beginning decoding, one section sequence code of this intercepting that can not know for sure, and main equipment produces with which multinomial, then need adopt heuristic definite, and concrete steps are following:
Main equipment possibly adopt M kind multinomial to certain specific slave unit.Slave unit then need carry out M time and sound out when deciphering.It is since the 1st kind of multinomial; Sound out always and decipher M multinomial, during, if N is (1≤N≤M) inferior exploration decoding; Judged correlation; Think then and found N multinomial with the multinomial of this emission of main equipment coupling that then slave unit is waken up and according to the meaning of N multinomial representative, completion is operated accordingly.Preferably; If this operation is can not be by the instruction of misoperation (such as valve-off); Slave unit can continue to receive more code element continuously again, adopts N the pairing decoder of multinomial again, and repeatedly its correlation is judged in decoding; And according to the number of times of successfully judging correlation and decoding total degree, whether decision carries out this operation.If M exploration do not judge that all correlation, the data that this reception then is described are that error code has taken place for noise or communication, do not do any operation, slave unit gets into rest period from detector, surveys the arrival of phase up to the next one.Certainly,, also can carry out M decoding parallel decoding,, judge whether the information of receiving that main equipment is sent according to decode results if adopt processor at a high speed to accomplish work decoding in the slave unit, and by that decoder completion.
In wireless communication system of the present invention, because main equipment possibly be directed against a plurality of slave units, and accomplishes different communication requirements, then the multinomial number of main equipment employing possibly be far longer than M.Wherein, some multinomial wakes up or broadcasting command such as broadcasting to all slave units; Some only to a part of slave unit, wakes up or group command such as group; Some is only to certain specific slave unit, wakes up or orders such as single slave unit, perhaps to the on/off valve order of some slave units.In the practical application, dissimilar communication requirements can be selected the different multinomial of coefficient or exponent number for use.
Wake up or order for broadcasting,, can select the m sequence for use, to obtain best pseudo random sequence because the multinomial that needs is fewer.
Wake up or group command for group, can be with the binary system group number of non-zero directly as multinomial; Perhaps group number is related correspondingly with multinomial; Perhaps with in the binary system group number or front or rear insertion some are fixing 0 or 1, increase its exponent number value.But the polynomial coefficient that obtains can not be 0 entirely.
Wake up for single slave unit, can be with the identity recognition number (ID) of the binary system slave unit of non-zero or the part (following general designation ID) of ID, directly as multinomial; Perhaps that ID is related one to one with multinomial; Perhaps in the centre of ID or front or rear face insert one or more fixingly 0 or 1, as multinomial, but its coefficient can not all be 0.
For the control command of single slave unit, can adopt ID to add the mode of a fixing non-null sequence of preset binary system, obtain multinomial, this preset non-null sequence of binary system is corresponding with this control command; Certainly, this sequence also can be inserted in the middle of the ID, also can disperse to insert ID number the centre or before or after.Slave unit utilizes this multinomial decoding, after the judgement correlation, then can carry out this order, such as driving valve or closing valve.
Certainly; In another embodiment; If main equipment produces after the said sequence code said sequence code negate, then the step of carrying out corresponding operating according to decode results of the specific slave unit among the foregoing description step S2 comprises: to decipher the back continuously the number of output 1 count; When whether the number of judging output 1 continuously surpasses preset limit value, judge correlation, polynomial exponent number and the coefficient according to employed decoder carries out the operation of corresponding demand then.
About the step of operating accordingly according to decode results in the foregoing description; Also should be noted that; Because main equipment is when having certain communication requirement, exponent number, the specific multinomial of the feedback shift register in the exponent number of its employed feedback shift register, specific multinomial and the specific slave unit are identical, mate with the coding/decoding multinomial of the feedback shift register that guarantees main equipment and specific slave unit; Could export continuous 0; Thereby the receiver by slave unit is discerned, and operates accordingly, has solved the identification problem.For the random code that produces because of noise, after the substitution formula (3), entirely its output is not 0, and, export 0 probability continuously and form progression with the increase of input number of times and descend.Suitable when the exponent number of feedback shift register, when the number of the continuous output 0 of requirement is abundant again, let the probability of the continuous output a plurality of 0 of decoder level off to 0 because of noise, so just solved the problem of noise jamming (false wake-up).
In a specific embodiment; If communication requirement is all slave units to be broadcasted wake up, then the sequence code that encoder produced in the main equipment can be the m sequence, optional 20 rank of this m sequence; Be n=20, and each slave unit all comprise and the pairing decoder of said encoder.Certainly, the encoder in the main equipment also can be other sequence, as long as guarantee all to include in all slave units the decoder that the encoder with main equipment is complementary.
In another specific embodiment; If communication requirement is the slave unit of particular group to be organized wake up; Then the particular polynomial coefficient is the combination of binary system group number and preset first fixed sequence program of the slave unit of this particular group, and the binary system length after the combination is 19, and promptly exponent number is 19.And all comprise in the slave unit of this particular group and the pairing decoder of said encoder.Should be noted that why add a fixed sequence program at the back in group number, is because consider that group number is generally shorter, adds the probability that can reduce false wake-up behind the fixed sequence program.
In another specific embodiment; If communication requirement is for to carry out single waking up to specific slave unit; Then the particular polynomial coefficient is the combination of at least a portion of binary system ID number and preset second fixed sequence program of at least a portion of binary system ID number or the said specific slave unit of said specific slave unit, and comprises in the said specific slave unit and the pairing decoder of said encoder.In a specific embodiment, such as, get in ID number 16 and after its certain, insert one 1, be transformed to exponent number and be a multinomial of 17.
In another specific embodiment; If communication requirement is to specific slave unit sending controling instruction; Then this particular polynomial coefficient of the encoder of main equipment binary system ID number at least a portion that is this specific slave unit and the combination of the pairing binary sequence of said control command, and comprise in the said specific slave unit and the pairing decoder of said encoder, if at least a portion of ID number of specific slave unit is 16; Then open the valve instruction and can be provided with 5,21 altogether.
In another specific embodiment; If communication requirement opens or closes the valve instruction for sending to specific slave unit; Then the particular polynomial coefficient of the encoder of main equipment is that at least a portion of binary system ID number of said specific slave unit is instructed the combination of pairing binary sequence with the preset valve that opens or closes; And pairing binary sequence is different respectively with closing the valve instruction to open the valve instruction, and difference is the bigger the better.And comprise in the said specific slave unit and the pairing decoder of said encoder.If at least a portion of ID number of specific slave unit is 16, then closes the valve instruction and can be provided with 5,21 altogether.
At least a portion of more than using group number or ID number and a specific binary sequence are combined to form and wake up or when controlling multinomial, preferably the sequence code of the sequence code cycle length that produces of those combination backs.
In another specific embodiment; When main equipment is carved with different communication requirements when different; For example certain time point need carry out single waking up to certain specific slave unit; Another time point need send to this specific slave unit again and close the valve instruction, then will inevitably comprise two decoders in this specific slave unit, and these two decoders are respectively with to produce two encoders of sequence code respectively corresponding because of two different communication requirements in the main equipment.After the sequence code that receives main equipment sometime and sent; Adopt the method for souning out to use these two decoders that the sequence code that is received is deciphered successively; Decoding coupling (promptly continuously output preset number 0 or 1) time; Can judge the communication requirement of main equipment according to employed decoder, and then operate accordingly.Certainly, the quantity of the decoder in the slave unit of the present invention does not limit two, and along with increasing of communication requirement, the quantity of the decoder in the slave unit can be any amount.But quantity is many more, and amount of calculation is just big more.In addition, also should be noted that if when comprising at least two decoders in the specific slave unit; Can be through the pairing polynomial exponent number of each decoder accuracy that improves decoding inequality in this slave unit be set; Correspondingly, the multinomial exponent number of the employed corresponding encoder of main equipment is also inequality, for example; Main equipment is being broadcasted all slave units when waking up, and the polynomial exponent number of employed encoder is 20; Main equipment is being organized a certain group of slave unit when waking up, and the polynomial exponent number of employed encoder is 19; Main equipment is when carrying out single waking up to some slave units, and the polynomial exponent number of employed encoder is 17; Main equipment is when some slave unit transmissions are driven valve or closed the valve instruction, and the polynomial exponent number of employed encoder is 21.
In addition, in order to improve the accuracy rate that slave unit leaves valve or closes valve, be example to close valve; After slave unit receives one group of sequence code; And use a plurality of 0 o'clock of certain decoder decoding back output wherein, and the multinomial coefficient of this decoder be ID number at least a portion and the combination of closing the valve instruction of this specific slave unit, to be main equipment to this specific slave unit send the communication requirement that this sequence code representative then is described closes valve and instruct; For avoiding misoperation; Can let receiver receive more code element continuously again, use this decoder repeatedly the sequence code of new reception to be deciphered, in repeatedly (for example 5 times) are deciphered at this; More than half (for example 3 times) are wherein arranged is correct, then closes the valve operation according to this pass valve instruction again.Likewise, drive valve too.
In a further advantageous embodiment, main equipment to the logical zero in the sequence code or 1, carries out graceful Chester coding, non-return-to-zero coding or return-to-zero coding after producing sequence code.Adopt Manchester's code, the receiver of slave unit is isolated bit synchronization signal easily fast, thereby can be shortened the detection phase.It is emphasized that the radio communication coded system of the form that other is any, such as the multi-system modulation, the different modulating mode all belongs within the scope of the present invention.
In a further advantageous embodiment; After main equipment produces sequence code, also can carry out scrambling or merging to said sequence code, correspondingly, specific slave unit is after receiving said sequence code; Earlier this sequence code is gone to disturb or go to merge, decipher again and operate accordingly according to decode results.In an example, scrambling is merged into a sequence code that is produced and a fixed sequence program sign indicating number is carried out XOR for a sequence code that is produced and a pseudo random sequence code are carried out XOR.Should be understood that disturbing and going to merge also is same computing.
The workflow of main equipment and slave unit is described respectively below in conjunction with Fig. 4:
The workflow of main equipment at first is described: main equipment is when having communication requirement, by specific encoder formation sequence sign indicating number, and in preset time T
sIntroversive each slave unit sends this sequence code continuously; This specific encoder is the feedback shift register that is made up by particular polynomial, and feedback shift register needs initialization before startup, but can not be 0 entirely; The coefficient of this particular polynomial is relevant with communication requirement with exponent number, and is not 0 entirely.Preset time T
s>=T+t, wherein T is the rest period of slave unit, and t is the detection phase, and rest period constitutes a dormancy awakening cycle with the phase of detection sum.After main equipment has sent sequence code, can get into proper communication with specific slave unit, the duration is T
cExchanges data finishes, and specific slave unit gets into dormancy.If after the intact sequence code that main equipment sends, need not continue to communicate with slave unit, then slave unit is accomplished corresponding operation back and is got into rest period, no longer continues to communicate by letter with main equipment.Obtain closing the valve order such as slave unit, automatically perform and close the valve operation, end of operation gets into rest period, at this moment T
wAnd T
cAll be 0.For the slave unit of communication failure, like slave unit 3, main equipment need start the mistake treatment mechanism to be handled.
The workflow of each slave unit of explanation below: slave unit according to fixing cycle T+t alternation in the state of dormancy-reception one dormancy-reception.In time T, slave unit is dormancy, does not receive any data, and quiescent current is extremely low, reaches below several microamperes.In time t, slave unit is in the detection accepting state.At this moment, divide two kinds of situation to handle, if processor processes speed is enough high, but then parallel processing, while promptly receive the work decoding that carries out one or more decoders.Otherwise, can a plurality of continuous code element that receive be stored earlier, after finishing, reception carries out one or many decoding computing again.If all decode results are not all judged correlation, explain that then the sequence of receiving is noise or makes a mistake, this slave unit is not done any response and is got into rest period received signal.If certain decoder is judged correlation; The communication requirement of the sequence code representative of then representing main equipment and being sent is to point to this decoder of this slave unit; And judge it specifically is what communication requirement according to the coefficient of the proper polynomial of presently used decoder; Then, slave unit gets into waits for the efficient communication state, and the stand-by period is T
wAt T
wDuring this time, slave unit still is in accepting state, but can not proper communication.Send wake-up signal T at main equipment
sDuring end, the proper communication that master-slave equipment can be scheduled to is up to sign off.If take place that communication makes mistakes etc. problem, then get into the fault processing flow process.
Need to specify to be that when slave unit wakes bit stream up in reception, generally require main equipment at first to send a string bit synchronization sign indicating number (claiming midamble code again), slave unit carries out the separation of synchronised clock according to the bit synchronization sign indicating number.Because among the present invention; The pseudo random sequence that main equipment sends; In a segment encode was long, 0 number and 1 number were equal basically, and long continuous 0 or continuous 1 situation can not occur; It can be used as bit synchronization and uses, and just effect is worse than slightly and sends 01010101010...0101 sign indicating number clocklike.If in the receiving circuit of slave unit, the bit synchronization split circuit requires to send the bit synchronization midamble code of better quality, then can adopt graceful Chester coding to address this problem, and makes to receive the bit synchronization that function is isolated better quality.Like this, the sequence code that main equipment sent possesses bit synchronization, wakes and carry the multi-functional of information up.
In addition, in the sequence code that main equipment sent, also carry an important time reference information, after slave unit calculates this time reference information, can with main equipment on the deadline synchronously.What especially send at main equipment is under the situation of broadcasting when waking or organizing the sequence of waking up up; Then can make all slave units in the main equipment coverage; Perhaps one group of slave unit; Synchronous with main equipment in time, also accomplish synchronously in time thereby make between a plurality of slave units, be the time-based communication time benchmark after waking up.After calculating this time, just can calculate and wake the time T that communication is waited in the back up
w, as shown in Figure 4, so at T
wIn the time of waiting for, slave unit also can get into dormancy, can further reduce power consumption like this.Computing time, the concrete implementation method of benchmark was following:
When certain decoder of slave unit, judge correlation after, then confirmed the exponent number n and the coefficient of this decoder, and obtained the correct code element that receives more than or equal to n, therefrom take out n correct code element, called after sequence L here, the length of L is n.Slave unit uses these coefficients, produces an encoder identical with main equipment, and the use initialization value identical with the feedback shift register of main equipment come the feedback shift register in the initialization slave unit, and establishes variable k=0.Carry out the coding computing identical with main equipment then, shift register whenever moves one, and k adds 1; Value in the register can change simultaneously, value in the register and L is compared, not etc.; Then continue displacement and k and add 1, the value in register is with till L equates, at this moment; Obtain nonzero value k, if baud rate is b, then the window phase of slave unit and main equipment begin to send the time difference between moment of wake-up signal and are: k/b.If the time of processor calculating and processing is long, can not ignore because of the requirement of time reference precision, then need compensate (can use the computing time of processor timer or other method in the processor to obtain) to computing time.Do not considering under the situation of computing time compensation that so the moment that main frame begins to send wake-up signal is positioned at k/b before the moment that receives sequence L.And T
w=T
s-k/b.Need to prove that the sequence that feedback shift register produces all has some cycles.The sequence that linear feedback shift register produces, long period is 2
n-1, such as the m sequence, the cycle of nonlinear feedback shift register can be longer.In the practice, if T need calculate in system
wOr equipment needs time synchronized, and the sequence code that then feedback shift register produces in the main equipment transmits with certain baud rate, the time of in the sequence code one-period, sending should>=T
s, promptly at T
sTransmitting time in, can only send the sequence code in the one-period at most, otherwise may make mistakes computing time during benchmark.So, if adopt linear feedback shift register, then the m sequence is a best choice; If the employing nonlinear feedback shift register then can be selected the m sequence for use.
Illustrating this wireless communication method below, is example with baud rate 19200bps here, calculates and adopts in the system of the present invention, the value of window (detection phase) t.Suppose to adopt the feedback shift register of rank n=20, its multinomial is preferably selected primitive polynomial for use.Then main equipment is when having communication requirement, and at first the value of each register of initialization (can not all be 0) according to the synchronised clock of 19200bps, with the sequence code of feedback shift register generation, is launched later on through baseband coding and modulation then successively, and the duration is T
sT
sValue comprehensively confirm according to the requirement of power consumption and other are required.Slave unit under the present technical conditions, generally will be waited for the time of 3 bytes from the dormancy to the accepting state, the separated in synchronization mechanism of receiver just can be isolated stable bit synchronization.Simultaneously, begin the correct code element that receives to decoder input, behind n bit of displacement input (n=20 here), the correct data that each register of decoder all is received refreshes, and old incorrect data are moved out of.At this moment, feedback shift register begins to export 0, behind continuous output K individual 0 (K can equal n, also can be a bit larger tham, or be slightly smaller than n, determines in the different application, adopts K=n here), has just found the signal relevant with communication requirement.Then find the time of wake-up signal cost to be at detector t:
t=(3*8+n+K)/19200=(3*8+20+20)/19200≈0.00333s=3.33ms
This time is exactly window time t of the present invention, need not double, and for more reliable, value is a little longer also passable, such as 3.5ms or 4ms.
Fig. 5 shows the building-block of logic of wireless telecommunication system embodiment one of the present invention; This wireless telecommunication system comprises main equipment 100 and at least one slave unit (only showing specific slave unit 200 among the figure), and main equipment 100 when communication requirement is arranged to specific slave unit 200 transmission information.Main equipment 100 comprises the coding unit 110 and transmitting element 120 that connects successively, and specific slave unit 200 comprises receiving element 210, decoding unit 220 and the control unit 230 that connects successively.In this embodiment; Coding unit 110 is used for according to specific encoder formation sequence sign indicating number; Wherein, Said specific encoder is the feedback shift register that is made up by particular polynomial, and the coefficient of said particular polynomial is relevant with communication requirement with exponent number, and polynomial coefficient and initial value all are not 0 entirely; Transmitting element 120 is used in Preset Time sending said sequence code continuously to each slave unit, and said Preset Time more than or equal to rest period of said slave unit with survey the phase sum, said rest period constitutes a dormancy awakening cycle with the phase of detection sum; Receiving element 210 is used for receiving said sequence code in the detection phase; Decoding unit 220 is used to use the decoder corresponding with said encoder that said sequence code is deciphered; Control unit 230 is used for operating accordingly according to decode results.The logical construction that should be appreciated that other slave unit is similar with the logical construction of this specific slave unit 200, different only be that certain or some employed polynomial coefficients of decoding unit is different.Certainly, a plurality of slave unit also might use identical decoder.Thereby can make main equipment use the different coding device to produce the different sequences sign indicating number according to different communication requirements; Have only the specific decoder of specific slave unit to carry out correct decoding to this sequence code; Therefore; Specific slave unit can be judged the communication requirement of main equipment according to employed specific decoder, thereby operates accordingly.What need special instruction is that main equipment among this paper and slave unit notion are relative definition.Any equipment in the system, when needing initiatively to initiate communication, it can remove to wake up and control miscellaneous equipment according to the step of the main equipment among this paper.The role who is master-slave equipment can exchange flexibly.
Should be noted that encoder and decoder that the present invention is mentioned can be realized also can being realized by software by hardware.The preferential software that adopts is realized, to reduce cost and to obtain better flexibility.
The above is merely the preferred embodiments of the present invention, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.All within spirit of the present invention and principle, any modification of being done, be equal to replacement, improvement etc., all should be included within the claim scope of the present invention.