J.J. Caffery, G.L. Stuber, "Overview of radiolocation in CDMA cellular systems," IEEE Comm. Magazine, vol. 36, Issue 4, April 1998, pp. 38-45.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....Mobile positioning is an essential feature of future cellular systems; it enables the positioning of cellular users in emergency 911 (E 911) situations. A recent government mandate for such services, given in [1] has led to the development of numerous mobile positioning systems (see, e.g. [2] and the many references therein) Such systems have many other applications, besides E 911 public safety, such as location sensitive billing, fraud protection, mobile yellow pages, and fleet management. In infrastructure based mobile positioning systems, the accurate estimation of the time and ....

....besides E 911 public safety, such as location sensitive billing, fraud protection, mobile yellow pages, and fleet management. In infrastructure based mobile positioning systems, the accurate estimation of the time and amplitude of arrival of the first arriving ray at the receiver(s) is vital (see [2], 3] Such estimates are used to obtain an estimate of the distance between the transmitter and the receiver(s) However, wireless propagation usually suffers from severe multipath conditions. In many of these cases, the prompt ray is succeeded by a multipath component that arrives at the ....

J. J. Caffery and G. L. Stuber. Overview of radiolocation in CDMA cellular systems. IEEE Communications Magazine, vol. 36, no. 4, pp. 38-45, April 1998.

....1 Introduction Mobile positioning is an essential feature of future cellular systems; it enables the positioning of cellular users in emergency 911 (E 911) situations. A government mandate for such services, given in [1] has led to the development of numerous mobile positioning systems (e.g. [2]) Such systems have many other applications, besides E 911 public safety, such as location sensitive billing, fraud protection, mobile yellow pages, and fleet management (see, e.g. 3, 4] In infrastructure based mobile positioning systems, the accurate estimation of the time and amplitude of ....

.... safety, such as location sensitive billing, fraud protection, mobile yellow pages, and fleet management (see, e.g. 3, 4] In infrastructure based mobile positioning systems, the accurate estimation of the time and amplitude of arrival of the first arriving ray at the receiver(s) is vital [2, 5]. Such estimates are used to obtain an estimate of the distance between the transmitter and the receiver(s) However, wireless propagation usually suffers from severe multipath conditions. In many of these cases, the prompt ray is succeeded by a multipath component that arrives at the receiver(s) ....

J. J. Caffery and G. L. Stuber. Overview of radiolocation in CDMA cellular systems. IEEE Communications Magazine, vol. 36, no. 4, pp.

....of arrival (AOA) of at least two distinct signals from known locations and (c) employing location fingerprinting schemes. Owing to the harsh multipath environment in indoor areas, techniques that use triangulation or direction are not very attractive and often can yield highly erroneous results [2 4]. Location fingerprinting refers to techniques that match the fingerprint of some characteristic of the signal that is location dependent. The fingerprints of different locations are stored in a database and matched to measured fingerprints at the current location of an MS. Some companies such as ....

J. Caffery Jr., G. Stuber, "Overview of Radiolocation in CDMA Cellular Systems", IEEE Comm. Mag, April 1998.

.... positioning system (GPS) receiver (e.g. 7] or by requiring only low accuracy of location [4] Traditional trilateration or triangulation approaches to accurate location determination rely on the device being located having a line of sight to one or more base stations with known location (e.g. [8]) Recently there has been some work into location determination, stimulated by findings presented by Capkun et al. 9] This work has highlighted the fact that it is possible for devices in a network to determine their own location by measuring only the distance to nearby devices. In all ....

J.J. Caffery and G.L. Stuber, Overview of Radiolocation CDMA Cellular Systems, IEEE Communications Magazine, April 1998.

....inteference cancellation algorithms previously applied to multiuser detection in [9] 10] 11] GSIC is applied here to a two dimensional radiolocation problem. Previous approaches to radiolocation for cellular communication systems use a combination of TOA and timedifference of arrival (TDOA) [12]. In the handshaking protocol considered in the sequel, TOAs, or equivalently RTTs are used to estimate ranges to each reference node from the master node. The use of squared range measurement differences allows for triangulation using a linear least squares algorithm, under the assumption of ....

J. J. Caffery, Jr. and G. L. Stiiber, "Overview of radiolocation in CDMA cellular systems," IEEE Commun. Mag., vol. 36, pp. 38-45, Apr. 1998.

....on the accuracy of mobile phone location. The FCC requires that by October 2001, the wireless operators locate the position of emergency callers with a root mean square error below 125m [9] Several radio location methods are proposed for locating the Mobile Stations (MSs) in cellular systems [2]: the Signal Strength method, the Angle of Arrival (AOA) method, the Time of Arrival (TOA) and Time Difference of Arrival (TDOA) methods. The Time of Arrival and Signal Strength methods use range measurements from the mobile device to several base stations to obtain its position. Thus, the ....

J.J. Caffery and G.L. Stuber, Overview of Radiolocation CDMA Cellular Systems, IEEE Communications Magazine, April 1998.

....infrastructure to obtain geolocation information. Each of these groups may be further divided into two. First, the MS uses signals transmitted by the BSs to calculate its own position and second, the BSs measure the signals transmitted by the MS and relay them to a central site for processing [3]. Theoretically, the position of a receiver can be estimated from the measurements of the arrival times, directions of arrival, or Doppler shifts of electromagnetic waves sent by various transmitters whose exact locations are known [4] Forward link hyperbolic location systems, often called ....

J.J. Caffery, Jr. and G.L. Stuber, "Overview of Radiolocation CDMA Cellular Systems," IEEE Communications Magazine, vol. 36, no. 4, pp. 38-45, April 1998.

....and radio distance for non line of sight paths. Another source of error, for both signal strength and timing based methods, is multipath propagation. This is not studied in this paper. An overview of radiolocation methods, including some methods to mitigate the NLOS problem, can be found in [6]. Positioning Methods Here, we propose three methods to estimate the position of an MS. The first, PGWC, is based on signal strength, the second, TWC, is based on time, and the third, PGWC TA, is a hybrid between time and signal strength methods. We will investigate the accuracy of these ....

....positions of all N BSs whose beacons the MS can decode. We call it UnWeighted Centroid (UWC) The CID method can be regarded as a special case of UWC with N = 1. Finally, the third benchmark method uses circular multilateration of propagation delays. This is sometimes known as Time of Arrival (TOA [6]) In our implementation of TOA, positions are calculated from the MS BS i propagation delays using a least squared error technique. Equal weights are used for the equations. When only two delays can be measured, the solution is ambiguous since two locations are possible. In this case, we select ....

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J.J. Caffery, G.L. Stber, "Overview of Radiolocation in CDMA Cellular Systems", IEEE Communications Mag., Vol. 36, No. 4, April 1998, pp. 38-45.

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J.J. Caffery, G.L. Stuber, "Overview of radiolocation in CDMA cellular systems," IEEE Comm. Magazine, vol. 36, Issue 4, April 1998, pp. 38-45.

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J.J. Caffery and G.L. Stu ber, "Overview of Radiolocation in CDMA Cellular Systems," IEEE Comm. Magazine, pp. 38-45, Apr. 1998.

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J. Caffery and G. L. Stuber, "Overview of radiolocation CDMA cellular systems," IEEE Communications Magazine, vol. 36, no. 4, pp. 38-45, April 1998.

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