# Method for locating subscriber's mobile station

**FIELD: radar engineering and cellular communication systems for locating mobile stations.**

**SUBSTANCE: proposed method is distinguished from prior art in saving satellite measurement results incorporating abnormal errors and reducing weight of these erroneous measurements followed by repeated searching for subscriber's mobile station location using corrected weighting coefficient. This operation is executed until sum of weighed error measures corresponding to corrected location of subscriber's mobile station using refined weighting coefficients reduces below threshold value. Corrected estimate of subscriber's mobile station location obtained in this way is assumed as final estimate of subscriber's mobile station location.**

**EFFECT: enhanced precision and reliability of locating subscriber's mobile station.**

**3 cl, 5 dwg**

The present invention relates to the field of radar and can be used in cellular communication systems to determine the location of a mobile station (MS).

Constant improvement of quality and expansion of services in cellular mobile communication makes it relevant to the decision problem of determining the location of the subscriber MS.

This task has a very wide range of applications. The location of the MS (location), you need to find the users who need medical, police or other assistance for the implementation of the control functions of the machinery, for example, ″ emergency″ or taxi, for special police or military purposes and the other One of the common ways the location is a method using satellite navigation systems, among which the most common is the system Global Positioning System (GPS) (GPS SPS Signal Specification, June 2, 1995, 2nd Edition)[1]. GPS is a system of transmitters satellite signals, which convey information on the basis of which you can determine the location of the observer. Fully functioning GPS includes more than 21 satellites, approximately evenly spaced around six circular orbits, with four satellites each, the orbits are at an angle of 55 degrees relative to the equator and are separated on the other multiples of 60 degrees longitude. The orbits have the radius 26,560 km and approximately circular. The orbital period of a satellite around the Earth is 11,967 hours. The GPS system is designed in such a way that at least four GPS satellite can be seen from the most distant points on the Earth's surface. This allows you to use the GPS system to determine the observer's position anywhere on the Earth. Each satellite are cesium or rubidium atomic clock, providing synchronization signals transmitted by the satellites. In the GPS system is constantly monitoring hours on satellites and, if necessary, corrects hours for each satellite.

Each GPS satellite continuously transmits navigation signals. In transmitted signals contain information about when this signal was transmitted, what are the coordinates of the satellite were in the moment and so the distance between the satellite and the GPS receiver can be determined by measuring the time delay between the time of signal reception by the GPS receiver and the time when the signal was transmitted by the satellite. The GPS receiver generates the same signal as the satellite, allowing the GPS receiver can estimate the time delay between signals. But as the clock of the GPS receiver is not exactly synchronized with the atomic clocks on the satellites, the GPS receiver estimates pseudoresistance.

Most who frequent reception of signals while the location is in an urban environment, therefore, most measurements of pseudoresistance will contain errors associated with indirect distribution of signals in an urban environment.

Therefore, the challenge is to determine measurements which satellites contain abnormally large errors, i.e. errors that can lead to large errors in determining the location. Another equally important task is the task of reducing the impact of these measurements on the final estimate of the MS location.

The solution of these problems it is necessary to increase the accuracy of the positioning MILLISECONDS.

One way to determine the satellites with abnormally large errors and reduce the impact of these measurements on the final evaluation of the location described in US patent N No. 5,841,399 "Fault Detection and Exclusion Used in a Global Positioning System GPS Receiver" J. Yu, H 04 B 7/185; G 01 S 5/02, Nov. 24, 1998 [2].

In the patent [2] proposed during location to be a weighted sum of the measures of the measurement errors of the distances from all the BS, and for the measure of error to take the squared difference between the measured distance and the distance to the estimated location of the MS. Find the location of the MS corresponding to the minimum weighted sum of measures of the errors, using the measurements of all base stations (BS), and compare its value with a threshold, which decides about the presence of erroneous measurements. If p is into decision errors, the amount for each BS weighted sum of the measures of the errors from all the BS, in addition to this. For each amount find the location of the MS corresponding to the minimum for this amount. Then find among the many data weighted amounts are the minimum and compare it with the threshold. These operations are repeated until such time as the weighted sum shall not be less than the threshold, then the received coordinates of the MS is taken for the final or decide that location failed.

The disadvantage of this solution is the impossibility of reliable detection of erroneous measurements in the case when two or more measurements of pseudoresistance contain anomalous errors, which is very typical in the case of locations in an urban environment. When abnormal errors contained in two or more dimensions, there can be a situation where the removal of one neosovetskogo measurement will lead to the fact that the value of the weighted sum of errors does not exceed the threshold, then the estimate of the location will be adopted for the final, which will lead to an increase in the error in the estimated location.

Closest to the claimed solution is the method described in US patent No. 5,831,576 â€œIntegrity Monitoring of Location and Velocity Coordinates from Differential Satellite Positioning System Signals, H 04 B 7/185; G 01 S 5/02, Nov. 3, 1998 [3].

This method of location is that:

1) take N signal the location, corresponding to each of the N BS;

2) on receipt of the signals of location estimate pseudoresistance from MS to each of the N BS;

3) for each BS determines a measure of the error in the estimated pseudoresistance to MS as the squared difference between the amount of estimated pseudoresistance with an estimated clock skew and the distance to the estimated location of the MS;

4) for each BS determines the weighting coefficient measures the error;

5) summarize the weighted error measures;

6) compare the weighted measures of the error threshold;

7) for the initial location of the MS receive that for which the sum of the weighted measures of error is minimal;

8) if the sum of the weighted error measures, corresponding to the initial location of the MS, greater than a threshold, determine the difference between the maximum weighted measures of the errors corresponding to the initial location of the MS;

9) if the difference between the maximum weighted error measures, which correspond to the initial location of the MS exceeds the threshold, then the weighted error measures exclude weighted measure of the error, which corresponds to the satellite with a maximum weighted measure of the error;

10) as the final estimate of the location of the MS receive that for which the sum of the weighted measures of error is minimal.

According to this method for determining octopole the program uses the signals of the navigation satellite systems.
One of the main features of satellite navigation systems is the precise synchronization of the transmitted signals. This allows to estimate the distance to the satellites by measuring the time delay between the time of transmission of signals from the satellites and reception of data signals on the MC. But even if there are no errors in the measurement of time delays due to inaccurate clock synchronization MS and the global time navigation satellite system, the calculated distance will not coincide with the true distances from the satellite to the MC. Distances, the resulting estimate the time delays of the signals (pseudoresistance)will differ from the true distances on the same unknown value is equal to the time clock skew MS, and global time navigation satellite system, multiplied by the speed of light. Then the distance from the MS to the satellite will be sum of pseudoresistance pr_{i}up to the satellite and an unknown clock skew τ multiplied by the speed of light:

range_{i}=pr_{i}+τ · c, where i∈ [1,N] (1)

On the basis of the above, for each satellite can be formed equation that resembles the following:

pr_{i}+τ · c=i∈ [1,N] (2)

where {x_{i},y_{i},z_{i}}, - coordinated the ATA i-th satellite.
Thus is constituted a system of N equations. The solution to this system of equations is to estimate the MS locationand evaluation of a temporary mismatchhours MS and the global time navigation satellite system. To solve this overdetermined system applies the method of least squares, namely, for each satellite is formed a measure of the error between the estimated distance to the satellite and the distance between the satellite and the intended location of the MS {x, y, z}

i∈ [1,N] (3)

The total measure of error measurements for all satellites is defined as the weighted sum of the squared values of the error measures generated for each satellite,

where σ

2 |

i |

For the estimation of the MS locationaccepted this pointin which the function (4) reaches its absolute minimum. In the described method, the minimum of function (4) is searched by the method of Newton. To detect abnormally large errors in the way proposed value function is AI F(x,y,z,τ
) (4) at the pointto compare with the threshold h_{FA}. Threshold values for different values of false alarm probability P_{FA}and the number of degrees of freedom, defined as μ =N-4, listed in this patent. A value of false alarm probability P_{FA}is set based on the requirements of the system locations.

If the value of the function Fin found the minimum does not exceed the threshold h_{FA}then the coordinatesundertake a final evaluation of the location. Otherwise, it is considered that the measurement of pseudoresistance contains anomalous errors that can lead to large errors in the estimation of location. To determine in what measure pseudoresistance contains anomalous errors, form a weighted measure of the error for each satellite in the following way:

i∈ [1,N] (5)

where S_{i,i}-diagonal elements of the matrix S.

Then there are two maximum weighted measures of errors,and forms the difference

Δ res=-, (6)

which is compared with a threshold:

whereand
- the probability that the weighted measures of error for satellites J_{1}and J_{2}will take the corresponding values ofand. If the difference (6) is greater than the threshold (7), i.e.,

then from the system of equations used to find the estimate of the location of the MS deletes the measurement. J_{1}the satellite and the operations described above are repeated again. Otherwise, it is considered that it is impossible to detect anomalous errors in this set of measurements, and the resulting coordinatesundertake a final evaluation of the MS location.

This invention allows for cases where the magnitude of the error in a single measurement pseudoresistance far exceeds the magnitude of the errors in the other dimensions of pseudoresistance, successfully detect in which of the measurement is given by this error and delete this satellite measurements from the system of equations, which can be used to find an estimate of the location of MS.

However, this invention has several significant drawbacks.

The exception of measurements of the satellite from the system of equations can lead to a significant increase in the geometric factor GDOP (Geometric Dilution of Precision), i.e. the deterioration of accuracy ("Network satellite navigation system", 2nd ed., per rabotno and expanded Ed. Professor Wasserchemie. "Radio and communications", M., 1993) [4]. Due to this can significantly increase the standard deviation of the estimate of the location (RMS). As a result, the actual error may be much larger than when estimating location using measurements of the satellite, contains an abnormally large error.

Most often determine the location of the MS is in an urban environment, and therefore abnormally large errors caused by multipath propagation of the signal can be contained in several dimensions of pseudoresistance. This may cause the values of multiple weighted measures of error will be approximately equal and

then according to the described method of determining the location estimate of the location of the MS or will be used to measure containing anomalous errors that will adversely affect the accuracy of the estimated location, or will be given of the denial in a location that is unacceptable in some circumstances.

The objective of the proposed method, - improving the accuracy and reliability positioning subscriber MS.

To solve this problem in the method of determining the location of the subscriber MS, namely, that receive N signals locations corresponding to each of the N base stations, on the accepted signals locate the estimate pseudoresistance from MS to each of the N base stations, for each BS determines a measure of the error in the estimated pseudoresistance to the subscriber MS, for each BS determines the weighting coefficient measures the error sum of weighted error measures and compare them with the threshold for the initial location of the subscriber MS accept that for which the sum of the weighted measures of error is minimal,

added the following operations:

- if the sum of the weighted measures of errors corresponding to the initial location of the subscriber MS, less than threshold, then specify the weights of the measures of the errors in such a way that,

for BS, for which a weighted measure of the error corresponding to the initial location of the subscriber MS, less the weighted average error measures for all BS, weights measures errors leave without changes

for BS, for which a weighted measure of the error corresponding to the initial location of the subscriber MS, more than the average weighted error measures for all BS, weights measures reduce errors,

- adjust the location of the MS using the adjusted weights,

- determine the sum of the weighted measures of errors corresponding to the adjusted location of the subscriber MS, using the adjusted weights,

- if the sum of the weighted measures of error, the corresponding adjusted mestopolozheniya.html MS, less than threshold, the specification of weights of measures of errors and correction of the location of the subscriber MS continue until such time as the weighted sum of the measures of the error drops below a threshold,

for a final assessment of the location of the subscriber MS accept that for which the sum of the measure of error, weighted adjusted weights is minimal.

A measure of the error in the estimated pseudoresistance to the subscriber MS is defined as the squared difference between the amount of estimated pseudoresistance with an estimated clock skew and the distance to the intended location of the subscriber MS.

Weights measures reduce errors, normalizing them to a weighted measure of the error.

Comparative analysis of methods of determining the location of the MS with the prototype shows that the proposed invention is substantially different from the prototype, as it allows to improve the accuracy and reliability positioning subscriber MS.

Comparative analysis of the proposed method with other technical solutions in this field of technology is not allowed to reveal the characteristics stated in the characterizing part of the claims.

Graphics used to illustrate the proposed solution.

Figure 1 - figure, reflecting the information about the character development in the area where the lock is required.

Figure 2 - illustration of a cellular network that includes MS and BS.

Figure 3 - example of a structural scheme for the implementation of the proposed method.

4 is an embodiment of the processing unit estimates a coordinate MILLISECONDS.

5 is a drawing, qualitatively illustrating the relationship of the assessment of the probability of presence of an abnormal errors, characteristics of development of the area and the elevation angle of the satellite.

The proposed method consists in the following:

1) take N signal locations corresponding to each of the N BS;

2) on receipt of the signals of location estimate pseudoresistance from MS to each of the N BS;

3) for each BS determines a measure of the error in the estimated pseudoresistance to MS as the squared difference between the amount of estimated pseudoresistance with an estimated clock skew and the distance to the estimated location of the MS;

4) for each BS determines the weighting coefficient measures the error;

5) summarize the weighted error measures;

6) compare the weighted measures of the error threshold;

7) for the initial location of the MS receive that for which the sum of the weighted measures of error is minimal;

8) if the sum of the weighted measures of errors corresponding to the initial location of the MS, less than threshold, specify the weighting coefficients of the measures of the errors in the following way:

a) for BS, for which a weighted measure of the error, the relevant boundary is the location of the MS, less than a weighted average measure of the error for all the BS, weights measures errors leave without changes

b) for BS, for which a weighted measure of the error corresponding to the initial location of the MS, more than the average weighted error measures for all BS, weights measures reduce errors,

(C) adjusting the location of the MS using the adjusted weights,

d) determine the sum of the weighted measures of errors corresponding to the adjusted location of the MS using the adjusted weights,

(e) if the sum of the weighted measures of errors corresponding to the adjusted location of the MS, less than threshold, the specification of weights of measures of errors and correction of the location of the MS continue, in accordance with item 8-a to 8-d, up until the sum of the weighted measures of error drops below a threshold,

9) as the final estimate of the location of the MS receive that for which the sum of the measure of error, weighted adjusted weights, minimum.

In the proposed method of positioning the term BS refers to satellites, terrestrial, BS, and various ground-based emitters satellite signals BS, as well as various combinations thereof. One of the main features navigation satellite systems and cellular systems, CDMA systems, the multiple access, code-division multiplexing), is the precise synchronization of the transmitted signals. This allows to estimate the distance to the satellites by measuring the time delay between the time of transmission of signals from the satellites and the time of receiving data signals in MILLISECONDS.

Figure 1 and figure 2 depicts a situation that is possible at locations in an urban environment. These figures illustrate how the can be located satellites and the surrounding buildings around the MS, a possible configuration of the cellular network, as well as what information is available about the character development in the area, where the location.

However, even if there are no errors in the determination of the distance related to noise, fading and megalocephaly, communications line failure, the clock synchronization of the MS and the global time navigation satellite system, the calculated distance will not coincide with the true distances from the satellite to the MC. And will differ by the same unknown value is equal to the time clock skew MS and the global time navigation satellite system, multiplied by the speed of light. Then the distance from the MS to the satellite will be sum of pseudoresistance (pr_{i}) to the satellite and an unknown clock skew (τ )multiplied by the speed of light,

range_{i}=pr_{i}+τ · c, where i∈ [1,N]. (9)

For each of the th satellite is formed a measure of the error between the distance to the satellite, equal to the sum of pseudoresistance expected clock skew τ multiplied by the speed of light, and the actual distance between the satellite and the alleged MS coordinates {x,y,z}

i∈ [1,N] (10)

where {x_{i},y_{i},z_{i}} the coordinates of the i-th satellite.

The total measure of error measurements for all satellites is defined as the weighted sum of the squared values of the error measures generated for each satellite

where W is the weight, which are based on measurement accuracy pseudoresistance for each satellite. The higher the measurement accuracy pseudoresistance, the more weight this dimension is included in the function (11).

For the estimation of the MS locationaccepted this pointin which the function (11) reaches its absolute minimum.

The minimum of the function (11) can be found well-known mathematical techniques, such as gradient method, described in the Handbook, Korn, ″ Handbook of mathematics″ , M, 1996 [5].

If we assume that measurement pseudoresistance for satellites contain only independent of the error described by a Gaussian distribution with zero mathematical expectation and variance of D_{i}=σ

2 |

i |

pr_{i}=pr

0 |

i |

_{i}i∈ [1,N] (12)

where pr

0 |

i |

_{i}error described by a Gaussian distribution with zero mathematical expectation and variance

D_{i}=σ

2 |

i |

and as the weighting factor, in the formula (11), take the reciprocal of the variance of this error, ie,

then the point estimate for the position of MS, the distribution of the random variablewill describe the distribution Chi-square with N-4 degrees of freedom (Brown, R.G., "Receiver Autonomous Integrity Monitoring", in "Global Positioning System: Theory and Applications, Volume 2", eds. B.W. Parkinson and J.J. Spilker Jr., American Institute of Aeronautics and Astronautics, 1996 [6]). This fact can be used to detect anomalous errors in the measurement of pseudoresistance. In most cases, the reception of navigation signals occurs in urban areas, and therefore the majority of metering the deposits pseudoresistance contain errors,
due to multipath propagation of the signal, noise and fading. Therefore, the obtained values ofmay not coincide with the true MS location {x_{0},y_{0},z_{0}}. Errors in the measurement of pseudoresistance caused by noise, describes a Gaussian distribution with zero mean. Such errors will be called normal. Abnormal'll call errors due to multipath propagation of the signal. The presence of abnormal errors in the measurement of pseudoresistance may be determined by the method described in [6]. To detect the presence of an abnormal error function value(11) at the pointis compared with the threshold h_{FA}. The threshold h_{FA}can be found from the transcendental expression

where R_{FA}- the probability that when the threshold is exceeded, the error in the measurements of pseudoresistance will be only normal. A value of P_{FA}is set based on the requirements of the system locations.

If the value ofin found the minimum does not exceed the threshold h_{FA}it is considered that the error in the estimation of the location of the MS is caused only by the presence of Gaussian errors, and coordinatesberotsana final evaluation location.
Otherwise, it is considered that the measurement of pseudoresistance to contain anomalous errors that can lead to large errors in the estimation of location. In case of exceeding the value ofthreshold h_{FA}you must determine which of the measurements pseudoresistance contains anomalous errors and, if possible, to reduce the impact of these errors on the final evaluation of the location. This method is proposed to solve this problem as follows. The values of the weighted squares of the errors for each satellite, defined as follows:

res_{i}=W_{i}f

2 |

i |

compared with threshold

If the values of the weighted square error (15) for a given satellite is greater than the threshold (16), the value of the weighting factor corresponding to the satellite, is changed as follows:

i∈ [1,N]. (17)

Then searched for a new assessment of the location, i.e. the minimum of the function (11), using the new weights (17). The procedure described above is repeated as long as the value function (11) at the point of minimum
will not become less than the threshold h_{FA}.

Thus obtained coordinatesundertake a final evaluation of the MS location.

The process of locating can be performed using the device, the block diagram of which is shown in figure 3, which consists of M demodulators 1 signals the location of M units 2 calculate the distance between the MS and each BS, M blocks 3 estimates of the signal-to-noise M blocks of 4 estimates of the probabilities of the presence of an abnormal error and block 5 generate estimates of coordinates. The demodulators 1 signal locations are on the MC. Blocks 3 estimates of the signal-to-noise and blocks of 4 estimates the probability of the presence of an abnormal errors are also in the composition of MILLISECONDS.

M demodulators receive signals from locations, each of the corresponding BS. From the first outputs of the demodulators 1 to the inputs of blocks 2 distance calculations are values of the time intervals between transmission and reception of the respective signals location. In blocks 2 distance calculations on these values formed the value of the distance according to the formula pr_{i}=c(t_{i}-t), where t is the transmission time of the signal BS, t_{i}the time of admission to the MS signal from the i-th BS.

On the second and third outputs of each of the demodulators 1 signal locations to form estimates of the amplitude and noise power, respectively. These values do the and the first and second inputs of each of the blocks 3 estimates of the signal-to-noise.

Obtained in the demodulator 1 estimation of signal amplitude and the noise power is fed to the input unit 3 estimates of the signal-to-noise ratio, where is formed the corresponding estimate. To the input unit 4 forming assess the probability of the presence of an abnormal error r receives data from the network about the elevation angles of the satellites, as well as information about the area in which the MS is. Depending on the elevation angles of the satellites and information about the building in unit 4's estimation of the probability of presence of an abnormal error r. Assessment of the probability of presence of an abnormal error r can be formed, for example, as follows:

,

where α c_{i}- the elevation of the i-th satellite, participating in the location, Na is the average height of buildings in the vicinity of the proposed location of the MS, Lc is the average distance between buildings in the vicinity of the proposed location of MS. Figure 5 shows a picture that is qualitatively illustrates the relationship of the assessment of the probability of presence of an abnormal error r, characteristics of development of the area and the elevation angle of the satellite.

Option execution unit 5 to generate estimates of coordinates is presented in figure 4.

Unit 5 generate estimates of coordinates contains the node 6 forming weight coefficients W_{i}node 7 generate summary measures of measurement errors F{X), node 8 determine the minimum is formed of the function F{X),
node 9 comparison of the generated function with threshold and node 10 the formation of new weights W_{i}.

Unit 5 generate estimates of coordinates is as follows.

At the input node 6 forming coefficients receives information about the distribution channel, namely the signal-to-noise and estimation of probability of presence of anomalous errors for each BS.

The weighting coefficients W_{i}are based on measurement accuracy pseudoresistance for each satellite. The higher the measurement accuracy pseudoresistance, the more weight this dimension is included in the total measure of measurement errors.

The weighting coefficients W_{i}can be formed, for example,

in the following way:

W_{i}=b_{i}· c_{i},

where b_{i}=1 for signal locations taken at high enough signal-to-noise ratio, providing a good accuracy of measurement.

b_{i}<1 for the location signals received with a low signal-to-noise;

with_{i}=1, for signal locations where the value of the likelihood that the presence of an abnormal errors below a threshold;

with_{i}<1, to signal the location where the value of the likelihood that the presence of an abnormal error above or equal to the threshold. This threshold is chosen based on the results of field tests of the algorithm location.

Not excluded and on what other methods of forming the weighting coefficients, which will improve the estimation accuracy of the coordinates.

The weights from the output node 6 of the formation of the weights and the measured distance from the input unit 5 to generate estimates of the coordinates of the MS is received on the input node 7 generate summary measures of measurement errors. For each satellite is formed a measure of the error (see equation (10)) between the distance to the satellite is equal to the sum of pseudoresistance expected clock skew τ multiplied by the speed of light, and the actual distance between the satellite and the alleged MS coordinates {x,y,z}:

The total measure of measurement errors is generated according to the formula (11). Formed the total measure of the measurement error comes from the output node 7 generate summary measures of measurement errors on the input node 8 determine the minimum total measures of measurement errors. In it for the estimation of the MS locationaccepted this pointin which the function (11) reaches its absolute minimum.

The minimum of the function (11) can be found well-known mathematical techniques, such as gradient method described in [5]. Assessment of the location of the MS and the value of aggregate measures of measurement errors at the point of this assessment is coming from the output node 8 of the determination of at least the input node 9 a comparison which compares C is achene summary measures of measurement errors with a threshold.

To detect the presence of anomalous errors the value of the function F{x,y,z,τ ) (11) at the pointis compared with the threshold h_{FA}. The threshold h_{FA}can be found from the transcendental expression (14).

Node 9 compare the value of the functionin found the minimum value is compared with a threshold. If the value ofin found the minimum does not exceed the threshold h_{FA}it is considered that the error in the estimation of the location of the MS is caused only by the presence of Gaussian errors, and coordinatesundertake a final assessment of the location and transmitted to the output processing unit estimates the coordinates of the MS 5. Otherwise, the total measure of the error of measurement is transmitted from the output node 9 of the comparison to the input node 10 the formation of the new weights. It is believed that the measurement of pseudoresistance contains anomalous errors that can lead to large errors in the estimation of the location and you must determine which of the measurements pseudoresistance contains anomalous errors and, if possible, to reduce the impact of these errors on the final evaluation of the location. In the node 10 of the formation of new weights for the total extent of measurement errors are determined by the values of the weighted squares of osibo is for each satellite according to the formula (15) and compared with the threshold (16).

If the values of the weighted square error (15) for a given satellite is greater than the threshold (16), the value of the weighting factor corresponding to the satellite varies according to the expression (17).

Then the new weights from the output node of the formation of new weights is transmitted to the input node to generate summary measures of measurement errors, which searched for a new assessment of the location, i.e. the minimum of the function (11), using the new weights (17).

Thus, in the proposed method, in contrast to the known methods it is proposed not to remove dimensions satellites containing anomalous errors, and to reduce the weight of these erroneous measurements, and then to look up the location of the subscriber MS using the adjusted weights. This operation is performed until such time as the weighted sum of the measures of the errors corresponding to the adjusted location of the subscriber MS, using updated weights will not become less than the threshold. Thus obtained was adjusted to assess the location of the subscriber's MS is taken as the final estimate of the location of the subscriber MS.

Thus, the obtained solution is an adaptive way of assessing the accuracy of measurements and changes the weights of the measurements on the basis of the obtained estimates. The proposed method allows to determine the proportion of each dimension in the final decision. This method of evaluation, in contrast to most of the known methods, which aimed at excluding measurements with large errors from consideration allows to use all available measurements. This provides a higher quality assessment in conditions where it is not possible to allocate sufficient to solve the navigation task, the number of measurements with small errors.

1. The method of determining the location of the subscriber mobile station (MS), namely, that receive N signals locations corresponding to each of the N base stations (BS), on receipt of the signals of location estimate pseudoresistance from MS to each of the N base stations, for each BS determines a measure of the error in the estimated pseudoresistance to the subscriber MS, for each BS determines the weighting coefficient measures the error sum of weighted error measures and compare them with the threshold for the initial location of the subscriber MS accept that for which the sum of the weighted measures of minimum error, wherein if the sum of the weighted measures errors corresponding to the initial location of the subscriber MS, less than threshold, then specify the weights of the measures of the errors in such a way that for BS, which is a weighted measure of the error, the relevant boundary is the location of the subscriber MS, less than a weighted average measure of the error for all the BS, weights measures errors leave without changes, to the BS, which is a weighted measure of the error corresponding to the initial location of the subscriber MS, more than the average weighted error measures for all BS, weights measures reduce errors, correct the location of the MS using the adjusted weights, determine the sum of the weighted measures of errors corresponding to the adjusted location of the subscriber MS, using the adjusted weights, if the sum of the weighted measures of errors corresponding to the adjusted location of the subscriber MS, less than threshold, the specification of weights of measures of errors and correction of the location of the subscriber MS continue as long as the sum of weighted measures of error drops below a threshold, for a final assessment of the location of the subscriber MS take the one for which the sum of the measure of the weighted error of the adjusted weights is minimal.

2. The method according to claim 1, wherein the measure of error for the estimated pseudoresistance to the subscriber MS is defined as the squared difference between the amount of estimated pseudoresistance with an estimated clock skew and the distance to the intended location of the subscriber MS.

3. The method according to claim 1, otlichayushiesya, what weights measures reduce errors, normalizing them to a weighted measure of the error.

**Same patents:**

**FIELD: radio engineering.**

**SUBSTANCE: proposed method used for detecting mutual time mismatch of base stations in cellular radio communication systems, for instance in cellular radio communication systems of third generation, to detect location of mobile user includes joint statistical processing of all qualified time mismatch signals of base stations so as to determine mutual time mismatch of signals coming from any pair of base stations of radio communication system.**

**EFFECT: enhanced precision.**

**4 cl, 13 dwg**

FIELD: radio engineering.

SUBSTANCE: method involves arranging base stations supplying services to objects belonging to given region in pentagon vertices. Its two non-adjacent angles are equal to 90° and vertex with an angle of 132° is between them. The other angles are equal to 114°. Communication zones cover territory under service without gaps. Their base stations have circular pattern and two radii of communication zones r and R related to each other as r=0.575R. The stations having lesser serviceability radius form a square which side is equal to 1.827*l*.

EFFECT: reduced service zone overlay degree; coverage of uneven and convex earth surface types.

3 dwg

FIELD: satellite navigation; location of position of mobile objects in space.

SUBSTANCE: "m" monitoring and correcting stations are formed around TV center, where "m" is any integer of navigation spacecraft forming local differential corrections which are transmitted to TV center via radio channel and then to mobile object through TV center transmitter without impairing present broadcasting; mobile object determines its coordinates by signals of navigation spacecraft with local differential corrections taken into account; coordinates thus determined are transmitted to TV center via radio channel and then they are transmitted to traffic control station; traffic control signals formed at traffic control station are transmitted together with coordinates of mobile object to nearest dispatching station by satellite communication channels where target designation signals are formed and are transmitted to mobile object.

EFFECT: enhanced precision of positioning and possibility of performing control of mobile objects.

1 dwg

**FIELD: radio communications; single-ended radio communications between moving vehicles having common starting point.**

**SUBSTANCE: proposed method for radio communications using radio communication systems characterized in effective operation when a number of systems mounted on board moving vehicles are communicating at a time involves dropping of low-power intermediate transceiving stations equipped with nondirectional antennas to effect radio communications that ensures electromagnetic safety for persons on board moving vehicles. Mentioned intermediate transceiving stations are pre-installed in mentioned moving vehicles.**

**EFFECT: reduced mass and size of transceiving stations, enhanced noise immunity of on-board electronic facilities.**

**2 cl 7 dwg, 1 tbl**

**FIELD: communications engineering; mobile communication systems.**

**SUBSTANCE: proposed mobile communication system has base station system incorporating servicing sectors of base transceiving stations, subscriber terminals, and switching center common for all base station systems that has switch, communication controllers, and central controller; the latter has main processor, means for allocating radio channels in base transceiving stations, means for ordering radio channel access, recording unit for j groups of transceiving devices of base transceiving stations, unit for specifying radio channels from j groups of frequency bands, and unit for assigning priority of subscriber terminal access to radio channels. Subscriber terminal is primarily given priority of access to radio channels of frequency group covering innermost area in cell and only when they are unavailable due to location of subscriber terminal beyond this area or when all radio channels of this group are completely busy is the subscriber terminal given access to radio channel of frequency group bearing numbers j reduced by one sequentially and also with priority.**

**EFFECT: enhanced capacity, reduced frequency resource requirement and cost of system, reduced inherent noise and provision for electromagnetic compatibility.**

**4 cl, 3 dwg**

**FIELD: radio communications using cellular communication systems; operating cellular communication systems and those under design.**

**SUBSTANCE: proposed radio communications process using cellular communication system depending for its operation on frequency reuse and sector structure of cells that incorporates provision for electromagnetic compatibility with electronic means of other cellular communication systems includes intentional division of frequencies assigned to each sector into several groups of different frequencies and radio coverage of disjoint-contour areas nested one into other for each j group by means of transceiving devices, j frequency group covering only j area. Subscriber terminals are primarily assigned priority of access to radio channels of frequency group covering innermost area of sector and only when these frequencies are unavailable and subscriber terminal is beyond this area, or radio channels of this group are completely busy, can this subscriber terminal be given access, also with priority, to radio channels of frequency groups whose numbers are reduced by one.**

**EFFECT: enhanced system capacity, reduced frequency resource requirement, system cost, and inherent noise.**

**4 cl, 1 dwg**

**FIELD: radiophone groups servicing distant subscribers.**

**SUBSTANCE: proposed radiophone system has base station, plurality of distant subscriber stations, group of modems, each affording direct digital synthesizing of any frequency identifying frequency channel within serial time spaces, and cluster controller incorporating means for synchronizing modems with base station and used to submit any of modems to support communications between subscriber stations and base station during sequential time intervals.**

**EFFECT: enhanced quality of voice information.**

**12 cl, 11 dwg**

**FIELD: radio communications engineering; digital communications in computer-aided ground-to-air data exchange systems.**

**SUBSTANCE: proposed system designed to transfer information about all received messages irrespective of their priority from mobile objects to information user has newly introduced message processing unit, group of m modems, (m + 1) and (m + 2) modems, address switching unit, reception disabling unit whose input functions as high-frequency input of station and output is connected to receiver input; control input of reception disabling unit is connected to output of TRANSMIT signal shaping unit; first input/output of message processing unit is connected through series-connected (m + 2) and (m + 1) modems and address switching unit to output of control unit; output of address switching unit is connected to input of transmission signal storage unit; t outputs of message processing unit function through t respective modems as low-frequency outputs of station; initialization of priority setting and control units, message processing unit clock generator, and system loading counter is effected by transferring CLEAR signal to respective inputs.**

**EFFECT: enhanced efficiency due to enhanced throughput capacity of system.**

**1 cl, 2 dwg**

**FIELD: radio communications.**

**SUBSTANCE: proposed method intended for data transfer to mobile objects from stationary one residing at initial center of common mobile-objects route using electronic means disposed on stationary and mobile objects involves radio communications with aid of low-power intermediate transceiving stations equipped with non-directional antennas and dropped from first mobile object, these intermediate transceiving drop stations being produced in advance on first mobile object and destroyed upon completion of radio communications between mobile and stationary objects. Proposed radio communication system is characterized in reduced space requirement which enhances its effectiveness in joint functioning with several radio communication systems.**

**EFFECT: reduced mass and size of transceiver stations, enhanced noise immunity and electromagnetic safety of personnel.**

**2 cl, 7 dwg, 1 tbl**

**FIELD: radio communications.**

**SUBSTANCE: proposed method for single-ended radio communications between mobile objects having common initial center involves use of low-power intermediate transceiver stations equipped with non-directional antennas and dropped from mobile objects. Proposed radio communication system is characterized in reduced space requirement and, consequently, in enhanced effectiveness when operating simultaneously with several other radio communication systems.**

**EFFECT: reduced mass and size, enhanced noise immunity and electromagnetic safety of personnel.**

**2 cl, 7 dwg, 1 tbl**

**FIELD: radar engineering and cellular communication systems for locating mobile stations.**

**SUBSTANCE: proposed method is distinguished from prior art in saving satellite measurement results incorporating abnormal errors and reducing weight of these erroneous measurements followed by repeated searching for subscriber's mobile station location using corrected weighting coefficient. This operation is executed until sum of weighed error measures corresponding to corrected location of subscriber's mobile station using refined weighting coefficients reduces below threshold value. Corrected estimate of subscriber's mobile station location obtained in this way is assumed as final estimate of subscriber's mobile station location.**

**EFFECT: enhanced precision and reliability of locating subscriber's mobile station.**

**3 cl, 5 dwg**