公开(公告)号：CA2117254A1

公开(公告)日：1993-04-15

申请号：CA2117254

申请日：1992-08-17

Applicant: MOTOROLA INC

Inventor： GOREHAM STEVEN A ,  VANDERSPOOL JAN P II

IPC: H04Q7/06 ,  H04H20/67 ,  H04J3/06 ,  H04L7/00 ,  H04Q7/08 ,  H04Q7/12 ,  H04Q7/36

Abstract: A simulcast transmission system (10) and method provides for time synchronizing data transmissions from a plurality of transmission stations (16, 18). The transmission stations (16, 18) include transmission clocks (36) for controlling the time of transmission of synchronization timing signals and data. The synchronization timing signals indicate a local time of transmission which are transmitted in response to system timing signals received from the control station (12). The control station (12) comprises apparatus (20) for generating and distributing the system timing signals, apparatus (26) for receiving the synchronization timing signals from the transmission stations, and apparatus (20, 22, 28) for generating and distributing time adjustment factor signals to the transmission stations (16, 18) in response to receiving the synchronization timing signals. The transmission clocks (36) are adjusted in response to the time adjustment factor signals for controlling the time of transmission of the data signals.

公开(公告)号：CA2120528A1

公开(公告)日：1993-04-15

申请号：CA2120528

申请日：1992-08-24

Applicant: MOTOROLA INC

Inventor： VANDERSPOOL JAN P II ,  GOREHAM STEVEN A

IPC: H04B7/005 ,  H04B7/145 ,  H04B7/26 ,  H04H20/67 ,  H04J3/06 ,  H04Q7/36

Abstract: A control station 12 initiates a system timing signal transmission which is re-transmitted from a satellite 14. In response to receiving the system timing signal, the control station 12 then generates a time correction factor which is distributed to a plurality of transmission stations 16, 18. The transmission stations 16, 18 in response to receiving the system timing signal transmission and the time correction factor distributed from the control station 12 generate a time adjustment factor which is used to correct the local transmission clocks 36, 36', thereby providing time synchronization of data transmissions generated from the transmission stations 16, 18.

公开(公告)号：EP1074095A4

公开(公告)日：2002-07-17

申请号：EP99918713

申请日：1999-04-20

Applicant: MOTOROLA INC

Inventor： VANDERSPOOL JAN P II

IPC: G01S5/10 ,  H04B17/00 ,  H04W64/00 ,  H04B7/005 ,  H04Q7/20 ,  H04Q7/34 ,  H04Q7/38

CPC classification number: H04W64/00 ,  G01S5/10 ,  H04B17/364

Abstract: Base stations (101-105) transmit, and a remote unit (117) receives a radio frequency (RF) location signal. The remote unit (113) then computes an observed-time-difference (OTD) for each base station at particular time t1. Observed differences in received signal times, and are reported to a Mobile Location Center (MLC) (111). Additionally, a Real-Time-Difference receiver (115) receives an RF signal from two or more base stations. The Real Time Differences between the base stations (101-105) are computed at a second time. These differences are also reported to the MLC (111). The MLC (111) computes an estimated RTD for the time period t1 via standard curve fitting algorithms, or simple interpolating algorithms. A corrected Time Difference of Arrival (TDOA) as determined by the remote unit (117) is computed based on the OTD measurements and the estimated RTD measurements.