Granted Patent B2

US 7,020,473 · App. 10/773,364 · Granted Mar 28, 2006

Abstract

Claims (34)

1. A method for finding the position of a subscriber in a radio communications system, comprising:

combining transmission signals from subscribers to form a transmission sum signal, which is passed by cables from a base station to at least two antenna devices for transmission;

combining received signals which are received from respective subscribers via the at least two antenna devices, the received signals being combined to form a received sum signal, which is passed by cables to the base station;

associating each individual antenna device with an individual area for radio communication with subscribers within the area;

individually choosing cable lengths, which are used for signal transmission, for each antenna device;

measuring a round trip delay time for the transmission signal and the received signal of a sought subscriber using the individually chosen cable lengths;

determining which antenna device originated the received signal of the sought subscriber based on the round trip delay time; and

determining the position of the sought subscriber to be the area associated with the antenna device which originated the received signal.

2. The method as claimed in claim 1 , wherein the cable lengths are provided by an optical connecting cable.

3. The method as claimed in claim 1 , wherein the cable lengths are provided by a glass fiber cable.

4. The method as claimed in claim 1 , wherein the cable lengths are chosen to have cable length differences Δ between cables associated with adjacent antenna devices, and wherein the cable length differences Δ are determined using the formulae:

Δ= LNG ( i +1)− LNG ( i )≧Const, where

Const= r*v/c

where:

i is a sequential variable to identify a cable length LNG which is associated with an i-th antenna device,

r is the range of radio communication for an individual antenna device,

v=2*10E8 m/s is the glass fiber group velocity, and

c=3*10E8 m/s is the group velocity in air.

5. The method as claimed in claim 1 , wherein

the radio communications system is an indoor radio communications system, and

each antenna device is associated with an individual building area.

6. The method as claimed in claim 1 , wherein the transmission signals and the reception signals are combined with a common connecting cable.

7. The method as claimed in claim 4 , wherein

the radio communications system is an indoor radio communications system, and

each antenna device is associated with an individual building area.

8. The method as claimed in claim 7 , wherein the transmission signals and the reception signals are combined with a common connecting cable.

9. A method for finding the position of a subscriber in a radio communications system, comprising:

combining transmission signals from subscribers to form a transmission sum signal, which is passed by cables from a base station to at least two antenna devices for transmission;

combining received signals which are received from respective subscribers via the at least two antenna devices, the received signals being combined to form a received sum signal, which is passed by cables to the base station;

associating each individual antenna device with an individual area for radio communication with subscribers within the area,

using different cable lengths for cables of different antenna devices;

determining delay time differences cables for the received signal of a sought subscriber;

determining which antenna device originated the received signal of the sought subscriber based on the delay time differences; and

identifying the position of the sought subscriber as the area associated with the antenna device which originated the received signal.

Assignments (13)