A method of reducing collisions between messages in a communication network, and device for its implementation

 

(57) Abstract:

The invention relates to cellular telephone systems, specifically to a system for increasing the reliability of the cellular telephone system in environments with multipath transmission of signals, or in conditions in which a large number of mobile phone units simultaneously try to access the base station. The technical result - reducing collisions between messages in the communication system. Collisions between messages simultaneously transmitted by multiple transmitters spread spectrum, reduced by the allocation message according to the available resource of the receiver. Transmitters can be mobile stations, and the receiver may be a base station in D (with parallel access code and seal channels) cellular telephone system. Each mobile station uses one or more methods of randomization to distribute messages. When the first randomization mobile station delay time their transmissions to the number of elementary parcels PN-code, which expands the transmitted signal. The noise function generates the identification number number that is uniquely associated with this mobility and the mobile station inserts a random delay between successive transmissions or samples if she does not receive confirmation after a specified period of interruption. A specified number of such transmissions is called a sequence of samples. When the fourth randomization mobile station inserts a relatively long random delay between successive sequences of samples, if she does not receive confirmation of any sample in the sequence. The noise level is reduced by minimizing the transmit power. The mobile station increases with the increment of the power of consecutive samples within each sequence of samples. The first sample of each sequence of samples is transmitted at a given level. 2 C. and 13 C.p. f-crystals, 6 ill.

The present invention relates to cellular telephone systems. More specifically, the present invention relates to a system for increasing the reliability of the cellular telephone system in environments with essentially multibeam transmission of signals or conditions in which a large number of mobile phone units simultaneously try to access the base station.

Many communication systems have many transmitters that are arbitrarily require access to one or more receivers. Local area network (LAN) is another example. In any such system, when multiple transmitters are trying to access at the same time, messages may overlap or "collide" with each other. The receiver cannot distinguish overlapping messages.

Two such Protocol multicostata, usually called " protocols "Aloha" and "Aloha split channels" described in Bertsekas and other Data Networks, Chapter 4, Prentice-Hall, Englewood Cliffs, 1987. In the Protocol "Aloha" each transmitter may transmit a message at any time. After discovering that the transmitted message has overlap, the transmitter waits for a random delay time and repeats the transmission of the message. In Aloha with channelized all messages are placed in the time interval of a given length. After discovering that the transmitted message has overlap, the transmitter makes the delay for an arbitrary number of time intervals and then repeats the message. In both random delay is introduced to prevent simultaneous transmission from a transmitter.

The use of modulation multiple access, code division multiple access (CDMA) is one of several ways to reduce restrictions in communication systems where there are a large number of users Sisson control transmission power in a CDMA cellular telephone system, and device for its implementation", and in the patent application U.S. N 07/543496, entitled "Method of generating the waveforms in a CDMA cellular telephone system and the system for its implementation", which are used in the present invention as analogues.

In the above-mentioned patent describes technology multiple access, where a large number of mobile stations, and each has a transmitter that communicates via the base station, also known as the points of contact of the cells using CDMA signals spread spectrum communications. Base stations connected to mobile telephone switching station (MTSO), which, in turn, is connected to the telephone network (PSTN).

Using CDMA spread spectrum maximizes the number of mobile stations that can communicate with the base station at the same time, because the same frequency band is shared by all stations. Each mobile unit has a pseudo-random (PN) code that is uniquely associated with it and which the mobile station uses to expand transmitted its signal. In the above patent, this PN code is called "long PN code". When initialized the call, i.e., the base cancernet extension signal, transmitted by the mobile station. Similarly, the mobile station can receive and resolve the extension of the signal transmitted by the base station. In some systems, the signals can also be modulated reference PN code.

However, for certain types of messages it is better to use the overall length of the PN-code, the unique long code for each mobile station. The message transmitted by the mobile station, trying to make a call, is an example of such messages. The mobile station wishes to make a call, you may send such requests in General "channel access", use the appropriate common PN code. The base station may monitor the access channel by eliminating the extension of the signal, using the appropriate code. The access channel is used as the message type used to make the call, relatively short compared to the voice message and the receiver can more easily control a relatively small number of access channels, the greater the number of individual channels of exchange of information with which mobile stations are associated with their unique long PN codes.

The access channel may be used n the time different from the time of the call. For example, the access channel may be used for the mobile station to answer an incoming call, carried out by the base station through the transmission channel signal search (personal) call.

Under all conditions discussed above, many mobile stations can transmit on the access channel at the same time. When two mobile stations perform transmission at the same time and not many rays, messages arrive at the base station are separated in time by a delay equal to the difference of double the distance between each mobile station and the base station. However, simultaneously transmitted messages will overlap if two or more stations are in the same range. Under most conditions, the base station can distinguish messages, since the time between arrivals of messages to the base station exceeds one PSH-interval.

Some of the working conditions contribute to the emergence of overlays. Blending can occur when a large number of mobile stations close to the edge of the cell at the same time, the condition causing the shutdown of the mobile stations. Transmission channel DOS and the same distance from the base station while they are on the edge of the cell.

It is also possible, when a large number of mobile users attempt to simultaneously make calls for other reasons, for example due to natural disasters. Simultaneous transmission of messages from multiple mobile stations on the access channel may exceed the maximum throughput of the processor at the base station.

The probability of overlapping access channel increases with the number of mobile stations and with increasing multipath (multiple) reflections. Multipath complicates the problem, because while the main signals of the two messages can be separated in time by more than one chip (interval), for the components of multipath transmission is not available. Moreover, as follows from the conjunction of the declared U.S. patent N 07/432552, entitled "Diversity receiver in a CDMA cellular mobile telephone system", filed on 7 November 1989, posted a receiver of a base station may have multiple correlators, which combine the received multipath components to improve the quality of communication. However, between multipath components may be ambiguity, which reduces the efficiency times oasim invention method, described below.

Disclosure of the invention.

The present invention reduce interference between multiple transmitters spread spectrum operating at the same time, and improves the distribution of messages among the resources available to the receiver. The present invention, in General, applicable to any communication system having multiple transmitters, trying necoordinirovannami to communicate with the receiver, including a local area network. In the illustrative embodiment of the present invention, the transmitters are movable (mobile) stations that are broadcasting on the access channel, and the receiver is a base station in a CDMA cellular communication network.

Each mobile station uses one or more methods of randomization for messages of its access channel. Randomization have the effect of separating the messages to reduce overlaps. The first randomization separates the signals of channel access by adding a random delay to each signal, and the second randomization separates them by arbitrary changes broadening direct sequence of each signal.

In the first randomization, called "PSH-random greater than or equal to one interval, but much less than the length of the message. On the contrary, the system of communication with the non-extended range Protocol Aloha split channels, shall, after the overlay is usually to wait for an appointment confirmation. If an overrun occurs, usually detected by the exclusion of confirmation, the mobile station must wait a random time delay, typically a few intervals before re-sending the message. Since the present invention is addressed to systems with spread spectrum, blending, of course, be reduced by the difference in the ranges described above and even more by adding PSH-random delay, which is usually much less than the length of the interval.

Although true randomization would be the ideal method of pseudorandomization, so that the base station can receive the amount of delay used by the mobile station, which is required for demodulation of the message. Delay PSH-randomization can be created using pseudorandomization using noise algorithm, which corresponds to a unique number associated with that mobile station. The input number can be an electronic serial number (ESN) of the station. An additional advantage of knowing the amount of delay added mobile station can more quickly detect the signal which the mobile station later passes on the information channel.

PSH-randomization more understandable in the context of the scenario, including the number of mobile stations simultaneously transmitting on the edge of the cell, i.e., at equal distance from the base station. In such a scenario, PSH-randomization increases the effective distance from each mobile station to the base station to an arbitrary value.

Multipath increases the difficulties experienced by the base station in the differentiation of signals simultaneously transmitted from different mobile stations. Low latency PSH-randomization may be insufficient to separate multipath components, which otherwise could be used spaced receiver (radio receiver system with diversity) to improve reception in multipath propagation.

The second randomization, called "channel randomisity", can be used to improve transmission quality in such conditions of multipath propagation. As discussed in the above patents and corresponding application, CDMA transmitter extends (in the W-code. In the channel randomization mobile station randomly changes the PN-code, which extends the signal of channel access (treatment). Change PN-code effectively creates a large number of channels of circulation. The base station has a receiver that corresponds to each possible channel. Even in conditions of multipath propagation, the base station can distinguish the simultaneous transmission of different channels of circulation.

When using channel randomization, the base station may send the mobile station a parameter representing the maximum number of channels of circulation, i.e., the maximum number of different PN-codes that it can take. The base station transmits the maximum setting of the channels of circulation to the mobile station during periodic communication sessions with the transmission of system information or "excess" between the base station and mobile (mobile) station.

The base station may be unable to distinguish between simultaneous transmissions transmission, if it takes more gear than the channels of circulation. For this reason, the mobile station may use a third randomized, called "inertia", in addition to PSH-randomly, attempts to communicate with the base station, called "breakdown". If the base station successfully recognizes and takes a sample, it transmits the acknowledgement to the mobile station. If the mobile station does not accept the confirmation of their test after the expiration of a specified period of time, it tries the other samples. A specified number of such samples is called the "sequence of samples treatment". The entire sequence of samples of the treatment can be repeated many times if the mobile station does not accept the confirmation of any sample in the sequence.

When randomization power loss (with delay), the mobile station includes an arbitrary delay between successive samples. Before sample mobile station generates a random number within a given range and holds the sample by an amount proportional to the random number.

When inertial (sustainable) randomization mobile station includes an arbitrary delay before each sequence of samples of the treatment. Before beginning the sequence of sample handling mobile station compares a randomly generated number with the given parameter inertia. The inertia parameter is verojatno the tion begins the sequence of samples of treatment, only if the random number is in the range of numbers specified by the inertia. If you are using the inertia, the mobile station performs the test at predetermined intervals as long as the test is not completed or will not confirm the a sample.

Finally, if the mobile station does not accept confirm any of the samples within a given number of sequences of samples of the treatment, she may abandon attempts.

In a cellular telephone system, the mobile station uses the channels of circulation for any nonverbal transmission to the base station. The mobile station may, for example, to request communications with the base station when the mobile user initializes the call. The mobile station may also be responsible for the channel to transmit (a message) from the base station to confirm the incoming call. In the latter situation, the base station may schedule their transmission on the transmission channel search call for more efficient processing of responses from the mobile stations, which can be expected within a certain period of time. Because the base station has some control over the situation, there is no need to require podio, can reduce the influence on each other by passing with a minimum capacity necessary to ensure that their signals were accepted by the base station. The mobile station transmits its first test at a power level that is somewhat smaller than its assessment necessary to reach the base station. This moderate rating can be given value, or it may be calculated in response to the measured level of the signal that the mobile station has or receives from the base station. The preferred implementation refers to the mobile station to measure adopted from the base station power. This received power (energy) is the transmitted power, reduced for losses in transit. Then, the mobile station uses this assessment taking into account the constant correction and adjustment factors, to set the initial transmit power. These adjustment factors can be sent to mobile station with the base station. Some of these coefficients correspond to the radiated power from the base station. Since the loss in the path from the mobile station to the base station is essentially the same as the area from the base to the mobile station, the signal is passed to the base station the options (factors) correction. After sending the first trial treatment at this minimum power level, the mobile station increases the power of consecutive samples in each sequence of samples of treatment on a given discrete value.

The foregoing, together with other features and advantages of the present invention will be better understood from the following description, claims and accompanying drawings.

Brief description of drawings

The invention is further illustrated by examples of its implementation with reference to the accompanying drawings, in which:

Fig. 1 depicts a timing diagram showing two signals with spread spectrum, which are demodulated (processed to eliminate scatter) single correlator at the receiver of the base station;

Fig. 2 is a chart of the impact of multipath propagation on the signals;

Fig. 3 is a timing diagram showing two signals with spread spectrum, which are demodulated by a separate correlators in the receiver of the base station;

Fig. 4 is a timing diagram showing a lot of trial treatment;

Fig. 5 is a block diagram of the preferred alternative implementation of the transmitter of the channel deposits.

The best variant embodiment of the invention.

In Fig. 1 two signals 10 and 12 channel demodulated on the receiver (not shown), which generates the corresponding picky 14 and 16 of the correlation. The signal 12 is supplied immediately after the signal 10, as, for example, a transmitter that emits a signal 12, is farther away from the receiver than the transmitter emitting a signal 10. The signals 10 and 12 may be signals with spread spectrum direct sequence CDMA cellular telephone system (not shown). In this embodiment, the transmitters are transmitting channel of the mobile stations, and the receiver is a receiver channel of the base station.

If the difference between the arrival time of the signal 10 and the signal 12 to the receiver of the base station is less than one chip (discharge) PN-code, which they have been modulated, the receiver may not be able to distinguish between the signals 10 and 12. This may be true for Fig. 1, when, for example, two mobile stations removed less than 120 meters (m), and the channel has a level of discharge in 1,2288 megahertz (MHz). It is considered that the imposition occurs when the receiver cannot distinguish the signals.

Each mobile station uses the "Panzie on the same channel. When PSH-randomization transmitter of the first mobile station may delay the signal 12 to the location of the delayed signal 18 and the second transmitter of the mobile station may delay the signal 12 to the location of the delayed signal 20. The noise function is preferred to generate the delay, because it enables the base station to determine the delay used by the mobile station. Then the base station can calculate the distance to the mobile station by measuring the total delay of a message received at a mobile station and subtracting the additional delay PSH-randomized.

The noise function is shown below (expression 1), uses an electronic serial number (ESN) associated with the mobile station, to create a delay. The noise function creates a delay PSH in the range from 0 to 512 units (bits chips) generator sequences PN-codes, which modulates the signal. Note that the maximum delay is much smaller than the delay created by other randomization discussed below. The base station can apply the indicator range, PROBE_PN_RAN, mobile station during system initialization or at other times. The delay range, R, is defined asnachamie 16-bit ESN;

H - the most significant 16 bits of the ESN;

D - number 14-fold relative to the least significant 12 bits of the ESN;

X represents the greatest integer less than or equal to X; represents bit-wise exclusive OR operation; and all other operations are integer arithmetic.

In Fig. 2 two signals 22 and 24 channel demodulated by the correlator receiver (not shown), which generates the appropriate picky 26 and 28 of the correlation. As shown in Fig. 1, the signal 24 comes at once (shortly) after the signal 22. The signals 22 and 24 detained using the method described above. The presence of multipath propagation creates multipath picky 30 and 32 of the correlation in the signals 22 and 24, respectively. But for picka 32 correlation about picka 26 posted correlation receiver of the base station should join picky 26 and 30, in order to improve the reception signal 22. However, the receiver may not be able to distinguish the signal 22 from the signal 24 if multibeam pincers 32 correlation adopted within one lobe (chip) picka 28 correlation. If picky 26, 28, 30 and 32 will be located very close to each other, the receiver will not be able to determine what pincers associated with any signal and, therefore, does not see the 24, the signal 24 will be shifted to the right in Fig. 2, and the pincers 32 correlation will not interact with the pincers 26 correlation. Then the receiver spaced signals of the base station can assume that the multipath components (emerging) close to one another, such as picky 26 and 30, are connected with the same transmitted signal 22 and, therefore, can be combined. Similarly, the base station receiver may assume that picky 28 and 32 are connected with the signal 24 and to combine them. Such assumptions are correct, because of multipath delay is usually less than one chip.

In Fig. 3 two signals 34 and 36 of channel demodulated by two separate correlators of the receiver (not shown). Two of the transmitter of the mobile stations (not shown) using the "channel randomization to modulate their respective signals 34 and 36 respectively different PN-codes, making the receiver of the base station requires the use of various correlators for demodulation. Although the signals 34 and 36 share the same frequency band, they must occupy different channels of circulation, as modulated using different PN codes. The receiver demodulates the signal 34, using the PN-code, the soy in the form of noise. This property, which allows the receiver to distinguish the signals 34 and 36, even in the presence of multipath propagation, it is well known in communication systems with spread spectrum. For each of the access channels, where the receiver of the base station can be received simultaneously with the reception of other channels, the base station must have a receiver that uses a PN code corresponding to this channel.

When channel randomization transmitter randomly selects an access channel from a specified range ACC_CHAN. The base station may submit this ACC_ CHAN mobile station during system initialization or at any other time in the process. Although the number of access channels, of which the mobile station may select, limited hardware considerations and bandwidth of the system, the preferred maximum of 32.

Even if you use PSH-randomization and channel randomization, the overlay message can occur if more than one transmitter selects the same channel access and pass the message on it at the same time. The transmitters can use the "randomize power loss" and "inertial" for additional distribution of messages in primenimye PN-randomization. Recent methods, as well as PN and channel randomization, are discussed below with reference to a timing diagram shown in Fig. 4, the system shown in Fig. 5, a timing diagram is shown in Fig. 6.

According Fig. 5, the processor device 100 of the mobile station performs steps in accordance with Fig. 6, beginning with step 102, in which the attempt communication with the base station (shown). The processor device may be any processor means, known to experts in the art, such as, for example, a microprocessor or microcontroller, a programmable matrix of logic elements for a group of characters or other type of logical device. The process may be initiated whenever the mobile station (not shown) must send information to the base station. The mobile station attempts to communicate by transmitting one or more trial access" 104, 106, 108, 110, 112, 114, 116, 118 and 120 to the base station. The sample consists of a single message and has a maximum duration of one "slot". The slot is a time interval system with which the base and mobile stations are synchronized in a CDMA cellular telephone system described above. Although the actual length of the slot is not critical which may be of the order of 60 MS. Thus, the delay PN-randomization is a very small part of the slot.

When trying to use the mobile station continues to transmit samples access to until one such sample will not receive confirmation from the base station. Thus, if overlap occurs, the message is not confirmed by the mobile station tries to make another sample. The specified number of samples treatment is called "sequence of samples. In Fig. 4 sequence 122 sampling consists of sampling access 104, 106 and 108, the sequence of 124 samples consists of samples 110, 112 and 114, and the sequence 126 sample consists of samples 116, 118 and 120.

Call initialization generates a signal 128 initialization, which is fed to the processor device 100. In step 130, the processor device 100 includes a reference sample PROBE, setting it to zero, and sets to zero the counter of the sequences of SEQ samples. In step 132, the processor device 100 calculates the noise function, described above, to obtain the delay PSH-randomization. The processor device 100 outputs a signal 134 delay, which corresponds to the PSH on the clock 136. The processor device 100 issues an informational data (soo is VCE. Data encoded messages 142 modulated PN long code 144, which is generated by the generator 146 sequences PN long code. As discussed above, generated by a specific PN long code 144 corresponds to the used channel access. This modulation is described in the aforementioned U.S. patent and related applications. Although to perform modulation is a block 152, a schema-based Exclusive-OR can be used any known design, this is equivalent, for example the multiplier. Finally, in response to the signal 134 delays the clock 136 generates sync signals 156, 158 and 160 on these elements, which ultimately delayed transmitted signal 164.

At step 162, the processor device 100 determines tries whether the mobile station to reply to the message from the base station or she is trying to initiate a request for communication with the base station. A call initiated by a user that is an example of attempts of the request, than trying to answer. If, as in Fig. 4, requires you request, the processor device 100 proceeds to step 166. However, if the requested address, the mobile station must perform the randomization and a loss of power at step 168. When randomization with pony option. Then in step 170, the processor device 100 should expect RS slots before proceeding to step 166. Processing device 100 may count the slots for the delay, because it takes the signal 172 counter slots from clock 136.

In step 166, the processor device 100 performs the same request/response test described above. If you want to try the query processor device generates the test inertia, which introduces a random delay in one or more slots between consecutive sequences of samples of the treatment. In the presence of the test inertia processor device 100 generates a random probability RP at the beginning of the slot at step 174. Given the parameter P represents the probability with which the next sequence of samples access. In step 176, the processor device 100 compares P with RP. If RP is less than P, the test inertia passes and the processor device 100 proceeds to step 178. If the test inertia fails, the processor device 100 repeats the test immediately before the beginning of the next slot (interval). If the processor device 100 determines that it is required to attempt to answer than try the query in step 166, it goes to the Sha, the base station may schedule sessions, need answers, so many mobile stations will respond essentially simultaneously.

In the example of Fig. 4, which represents the attempt of the request, the processor device 100 starts to step 174 at the beginning of the slot during the 180. Because the mobile station is attempting to make a request, it performs a test of persistence. The test does not pass, and re-entered immediately before the slot in the 182. If this second attempt the test passes, and the processor device 100 proceeds to step 178.

The processing device 100 performs channel randomization in step 178. It generates a random number RA in the range from zero to ACC_CHAN, which is a given parameter that represents the maximum number of channels of circulation. RA corresponds to the channel that will be transmitted sequence 122 samples of treatment. The processor device 100 sends a signal 183 selecting the channel on the generator 146 sequences PN-codes.

In step 184, the processor device 100 initializes the signal transmission 186 power for a given initial level INIT_PWR served on the transmitter 188 power in Fig. 5. In the CDMA cellular communication system, or any system of communication with the extension of the United signals many transmitters. The low level of background noise allows the receiver to more easily distinguish the desired signal from the spread spectrum of the noise. To minimize noise, the present invention minimizes power of each mobile station transmits. INIT_PWR is set to a value that is below the level usually required for the base station to receive messages. The processor device 100 preferably evaluates INIT_ PWR using the measured power level of the signals previously or currently received from the base station. Although part of the receiver of the mobile station is not shown, it is described in one or more of the above-mentioned U.S. patents and related applications.

In step 190, the processor device 100 turns off the system timer status access (not shown) that can be used to specify the processor device 100 that the mobile station has not received the message, which was expected from the base station in a given period of time. This timer should be turned off during attempts to contact it.

At step 192, the message is transmitted in a sample of 194 access the selected channel RA access. As shown in Fig. 4, PN-randomization additionally delays the start of the opening slot 60 MS, highlighted in Fig. 4 for clarity. The height of the sample 104 appeal is its relative power level. At the end of transmission of the sample 104 access during 196 processor device 100 includes a timer TA break internal confirmation. The specified parameter ACC_TMO pause indicates the length of the time interval that the processor device 100 must wait for confirmation of the sample 104. If the processor device 100 receives the signal 198 confirmation in the pause period, it proceeds to step 200 and aborts the attempt to query the channel. Then it can perform other actions that are not the subject of the present invention. When the period of time ACC_ TMO expires without receiving processor device 100 confirmation, it proceeds to step 202. In Fig. 4, the timer TA expires at time 204.

In step 206, the processor device 100 increases by the increment PROBE the value of its internal counter samples. In step 208, it compares PROBE with NUM_ STEP, which is a given parameter that specifies the number of samples of the treatment that must be performed in each sequence of samples of treatment, if no acknowledgement is received. In Fig. 4 NUM_STEP equal to three, since the sequence of 122 samples of treatment by the processor 210, the device 100 starts the randomization and the power loss of the samples. Randomization of samples with loss of power such randomization power loss described above, the difference is that randomization of samples with loss of power is performed between successive samples of the treatment sequence of samples of the treatment, while randomization with the loss of power is performed before each sequence of samples of the treatment. (The value) PROBE_BKOFF can be equal or not equal to the value of BKOFF. In step 210, the processor device 100 generates a random number RT in the range from zero to PROBE_BKOFF+1, which is a given parameter. In step 212, the processor device 100 waits RT slots. For example, in Fig. 4 RT is equal to "2", and the processor device 100 waits two slots up until the slot will not start at time 214.

In step 216, the processor device 100 changes the signal transmission 186 power number, which causes the transmitter 188 power to increase the transmission power by the number of decibels (dB), equal to 0.5 from PWR_STEP, which is a given parameter. The processor device 100 then proceeds to step 190 and transmits the sample 106 access for increased energy (power level) on the same access channel, RA, at time 218, which goes through RN-h is rarawa from 220 to 222 moment. It generates power loss (slow), RT, of the "1" and waits one slot at step 212 as long as the slot is not started at the time 224. Sample 108 access is transmitted when an additional power level on the same channel access, RA, is 226, which is RN-chip later than the beginning of the slot at the point 224. Since the end of the period of break in time 230 was not accepted no confirmation from the base station and sample NUM_STEP have been transferred, the processing unit proceeds to step 232.

In step 232, the processor device 100 includes a system timer status access (not shown) and proceeds to step 234. Having completed the transmission of a sequence of 122 samples of access, the processor device 100 increases by the increment SEQ value of its internal counter sequences of samples. In step 236, the processor device 100 compares with SEQ MAX_ REQ_ or SEQ MAX_RSP_SEQ, where the first is a given parameter to specify the maximum number of sequences of samples access to complete before exiting the attempts of the request, and the latter is a given parameter to specify the maximum number of sequences of samples access to complete before exiting the attempts of the answer. If one of these max is, is the quiet are not the subject of the present invention.

If the test at step 236 shows that there must be additional sequence of samples, the processor device 100 proceeds to step 240, where it performs the randomization power loss (slow), as described above with reference to steps 168 and 170. For example, in Fig. 4, the processor device 100 at the time 230 generates a random number RS of "I" and waits one slot at step 242 until then, until the start of the slot at point 248. Then, the processor device 100 returns to step 166 to begin the sequence of 124 samples of access.

The processing device 100 performs the steps of generating a sequence of 124 samples of access in the same way as when generating sequence 122 samples access. If, as in this example, you want to attempt the request, the processor device 100 performs a test of persistence at step 174 immediately before the slot is 248. The test fails and repeats immediately before the slot is 252. The third test passes, and the processor device 100 proceeds to step 178.

The processing device 100 performs channel randomization in step 178. Because the processor in the PA, which sequence of 124 samples should be transferred, may not be the same as the channel through which was passed a sequence of 122 samples of access. In step 184, the processor device 100 initializes the signal 186 power transmission, and in step 190, the processor device turns off the system timer status access.

At step 192, the message is passed to the sample 110 access, additionally delayed until 254 from the beginning of the slot in the moment 252 by RN-randomization. The processor device 100 proceeds to step 202 after the expiry of the period of break in time 258 without obtaining signal 198 confirmation.

When randomization deceleration at step 210, the processor device 100 generates a random number RT "3", and the processor device 100 waits for three slots in step 212 as long as the slot is not started at the time 260. At step 192, the processor device 100 increases the power of the signal 164 and passes the sample 112 access at the increased power level at the moment 262, which is RN-chip later than the beginning of the slot in the torque 260.

Processing unit 100 passes through the above steps for the third time, because it does not accept the confirmation signal before expiration of the period of time 266. It generates for overset sequence 124 sample access and the processor device 100 adds SEQ in step 234. The processor device 100 then generates the randomization slow "I" at step 240, waits one slot at step 242 before the start of the slot in the moment 276. Then, the processor device 100 returns to step 166 to start a sequence of 126 samples of access.

If you want to try the query processing unit 100 performs a test of persistence at step 174. In the example shown in Fig. 4, the test inertia is held on the fourth attempt, before the start of the slot in the moment 284. In the sequence of 126 samples of the access probe 116 access indulges in a moment 286, sample 118 - point 294 and the sample 120 - point 302, as described above.

After the mobile station has transmitted the sample 304 and before the break timer has reached the value ACC_TMO, the processor device 100 receives the signal 198 confirmation from the base station at time 306. In response to the signal 198 confirmation processing unit 100 proceeds to step 200 and prevents the request.

Although Fig. 4 illustrates an attempt request, try to answer the same. In an attempt to answer any test inertia should not be conducted before a break of 104 access. Instead, randomization deceleration in steps 168 and 170 is Voditsa before sequences 122 and 124 samples access between sequences 124 and 126.

It is obvious that other embodiments of the present invention may be offered by an expert in the field of engineering with regard to the considered conditions. Therefore, the invention should be considered within the framework of the following claims, which includes options for implementation, with the involvement of the description and drawings.

1. Device for reducing collisions between transmitted messages in a communication network having a unique identification code and containing a processing unit for issuing the message, the generator of clock pulses to provide a time delay depending on the unique identification code, the encoder delay message delay time and a transmitter for transmitting the delayed message to the receiver at the time specified in accordance with the unique identification code.

2. The device under item 1, characterized in that the transmitted delayed message is a signal spread spectrum direct sequence, advanced using psevdochumoy (PN) code sequence having the frequency of the basic assumptions, and the delay time is equal to or more than one elementary poselkovyh sequences for arbitrary choice of the specified PN-code sequence from a set of PN-code sequences in response to a random number, taken from a random number generator.

4. The device according to p. 3, characterized in that the processor device is additionally for receiving the confirmation signal in response to the confirmation, to measure the time between the transmission of a specific message and the specified confirmation signal and to signal a pause, if this time exceeds the specified parameter pause, and to provide additional messages in response to the signal a pause.

5. The device according to p. 4, characterized in that the processor device is advanced to count consecutive reports for submission to the counter samples and counter samples is reset upon reaching the specified maximum account of the trial, and to provide a signal power level to the transmitter to increase the power of each successive messages, and this power is at a predetermined minimum when the counter samples is in reset state.

6. The device under item 5, wherein the processing unit increases the power of each successive messages on the specified increment.

7. The device according to p. 6, characterized in that the processor device enters sauvestre the second random number.

8. The device according to p. 7, wherein the processing unit does not issue a message when the count of the samples is in the reset state, and the third random number is within a specific range of resistance.

9. A method of reducing collisions between messages in a communication network having multiple transmitters and at least one receiver, each transmitter has a unique identification code that generates the message delay message delay time, it is suitable to the specified identification code, and transmits the delayed message in the time limit specified in accordance with the unique identification code, and specified the transmitted message has a certain power level.

10. The method according to p. 9, characterized in that the transmitted delayed message is a signal spread spectrum direct sequence, advanced using psevdochumoy (PN) code sequence having the frequency of the basic assumptions, and the delay time is equal to or more than one elementary parcel.

11. The method according to p. 10, characterized in that prior to the specified transfer additionally carry out prostowanie delayed message to the selected PN code sequence.

12. The method according to p. 11, characterized in that the control confirmation signal from the receiver during a specified period of pause.

13. The method according to p. 12, characterized in that prior to the specified transfer additionally generate the first random number, choose the time period for deceleration of the specified range in response to the first random number, waiting a period of time slowing down.

14. The method according to p. 13, characterized in that the increase specified power level for a specified increment of power, increase the expense of the samples, compare the expense of samples with a given length of the sequence of samples and set the specified power level for a specified initial value, when the expense of samples equal to the given length of the sequence of samples.

15. The method according to p. 14, characterized in that it further repeatedly generate a second random number and compare it with the given parameter stability up until the second random number is within the range corresponding to the specified parameter stability.

 

Same patents:

The invention relates to the field of broadband mobile communications systems, in particular can be used in the direct channel standards UMTS and cdma2000, for adjusting the frequency of the reference oscillator required for coherent reception of messages, and can also be used when building satellite communication systems, where there may be large shift frequency

The invention relates to systems, spread spectrum communications, and more specifically to signal processing in the cellular telephone system

The invention relates to messaging systems with parallel access code and seal channels (CDMA), in particular to vnutristranichnoy the messaging system in which a fixed base stations are organized in groups of multiple use sequences

The invention relates to the field of radio engineering, in particular to cellular systems with code division multiplexing using the methods of a relay transmission to ensure continuity of communication of the mobile station with the base station

The invention relates to radio engineering, in particular to a device time synchronization for communication systems, including broadband signals

FIELD: data transfer networks, in particular Ethernet-based.

SUBSTANCE: device is made in form of multiple individually programmed single-port communication modules for access to common distributor bus 10, while each single-port communication module has: programmed micro-controller 1, made as access control block for transmitting environment Ethernet (MAC), containing processor with short command list (RISC CPU), and logic device 5 for distribution of data frames, including processing in real time scale and transmission to addresses frame destination ports of Ethernet data, received on said one-port communication module, transfer process is serial and is performed in save-and-send mode.

EFFECT: higher data distribution flexibility control.

2 cl, 7 dwg

FIELD: physics; control.

SUBSTANCE: invention relates to control for actuating safety equipment. The invention discloses a control unit and a method of actuating safety equipment, as well as a sensor for outputting an emergency signal. The control unit for actuating safety equipment includes at least one interface which outputs a digital information signal, which includes multiple simultaneously turned on current sources for acting on the front of the digital information signal.

EFFECT: providing electromagnetic compatibility of control signals.

10 cl, 6 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to wireless communication systems, where access to a communication channel is restricted with periodic intervals. A system and a method involve an assessment of the first probability of collisions in a channel at the beginning of the intermittent channel interval, where the assessed probability of collision is increased at detection of a transmission error in the section of one or more preceding channel intervals; setting of the size of a competitive transmission window at the beginning of the current channel interval in compliance with the assessed first probability of collisions in the channel; assessment of the second probability of collisions for the next channel interval; and dynamic size variation of the competitive transmission window for the next channel interval in compliance with the assessed second probability of collisions in the channel.

EFFECT: reduction of data losses at transmission.

16 cl, 13 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to a method of transmitting data telegrams (13a, 13b) from a transmitter (11a) to at least one receiver (11b), wherein the data telegrams (13a, 13b) to be transmitted are associated with a priority level which, during transmission of the corresponding data telegram (13a, 13b), specifies a priority to be considered. In the transmitter (11a) each priority level is associated with an intermediate storage area (17a, 17b); the data telegrams (13a, 13b) are transmitted over a physical communication medium (12) through different logical data connections (15a, 15b), wherein the number of logical data connections (15a, 15b) corresponds to the number of priority levels; data telegrams (13a) in the intermediate storage area (17a) associated with a lower priority level are transmitted through the logical data connection (15a) associated with said priority level until at least one data telegram (13b) is present in the intermediate storage area (17b) associated with a higher priority level, and the data telegram (13b) in the intermediate storage area (17b) associated with the higher priority level is transmitted through the logical data connection (15b) associated with the higher priority level.

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9 cl, 2 dwg

FIELD: physics, communications.

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13 cl, 5 dwg

FIELD: communication.

SUBSTANCE: invention relates to network communication technologies. Disclosed is method of serial interface in bus system containing two bus subscribers, exchanging messages by bus, wherein sent messages have logic structure corresponding to ISO 11898-1 standard for CAN protocol, said logical structure includes frame starting bit, arbitration field, control field, data field, cyclic redundancy code (CRC), acknowledgement field and sequence end frame, control field includes data length code containing information on data field length, characterised by that in presence of first mark (EDL) control field in messages comprises, in contrast to ISO 11898-1 standard for CAN protocol, more than six bits, wherein first mark (EDL) is implemented by recessive bit in control field, and in presence of first mark after recessive bit of first mark (EDL) in all information messages should be at least one dominant bit (r0, r1).

EFFECT: technical result consists in improvement of data transmission speed.

21 cl, 5 dwg

FIELD: information technology.

SUBSTANCE: present invention relates to network communication technologies. In method access to bus for sending any message is provided to a bus subscriber which becomes sender of said message, according to an arbitration method of corresponding standard ISO 11898-1 on CAN protocol, messages have a logic structure corresponding to CAN protocol standard, that is, consist of a start-of-frame bit, arbitration field, control field, data field, cyclic redundancy check (CRC) field, acknowledge field, and end-of-frame field, function of data transmission is checked during transmission by comparing a sent signal sent to bus connection unit with received signal (CAN_RX) received by the bus connection unit, method is characterised in that a sent signal (CAN_TX_DEL) delayed by a delay time (T_DELAY) compared to sent signal (CAN_TX) is held in sender, and undelayed sent signal (CAN_TX) or delayed sent signal (CAN_TX_DEL) is used for checking correct function of data transmission depending on a switchover.

EFFECT: technical result is faster data transmission in network.

33 cl, 3 dwg

FIELD: broadband cell radio communication systems, possible use for correcting frequency of supporting generator of mobile stations, necessary for provision of coherent message receipt mode.

SUBSTANCE: serial cyclic procedure of estimating mismatch and its compensation uses original algorithm for determining maximum of solving function by two of its values from the area where frequency is undetermined, thus making it possible to decrease frequency mismatch compensation time. Proposed procedure has increased interference resistance, because it uses additional digital supporting signal. Proposed algorithm can function with different, including substantial, values of original frequency mismatch. Algorithm is efficient both at beginning stage (in frequency capture mode) and during following automatic adjustment. Proposed variant of realization of frequency automatic adjustment allows precise adjustment of frequency of supporting generator even in case of very low signal-noise ratio for signal being received.

EFFECT: increased precision of estimation of frequency of input multi-beam signal, including cases with substantial frequency mismatches.

3 cl, 9 dwg

FIELD: modulation methods, possible use during transmission and receipt of information signals.

SUBSTANCE: in accordance to method, as encoding transformation, comparison of several bits of parallel, serial digital code or information units to sample of analog signal of given duration and certain shape is used.

EFFECT: direct transformation of digital signal or units of information by means of precisely generating analog signal from samples known in advance.

3 cl, 2 dwg

FIELD: communication systems.

SUBSTANCE: proposed method includes dynamic control of subscriber station transmitter considering noise level in vicinity of base station location and information load on base station by estimating quality of communication channel and accounting for network subscriber priority.

EFFECT: enhanced reliability of mobile communication system.

1 cl, 2 dwg

FIELD: information technologies.

SUBSTANCE: mobile device of wireless communication and methods for it include signal reception, saving of received signal part, identification of all possible pilot-signals by means of determination of information on slot border for saved part of signal, determination of information on frame border and/or information of scrambling code from saved part of signal by means of correlation of saved signal part with scrambling codes on the basis of information on slot border. In other versions of realisation searching is done in real time without signal saving.

EFFECT: increased probability of signal detection.

22 cl, 7 dwg

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