Digital signal transmitter synchronization system

• US 20060143677A1
• Filed: 02/16/2006
• Published: 06/29/2006
• Est. Priority Date: 03/30/2001
• Status: Active Grant

• Current Assignee: S. Merrill Weiss
• Original Assignee: S. Merrill Weiss
• Inventors: Weiss, S. Merrill
• Granted Patent: US 7,667,780 B2
• Time in Patent Office: Days
• US Class Current: 725/117
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/615 Signal processing at physical level signal processing in analog two-way television systems H04N7/173
• CPC Class Codes: H04N 5/38 Transmitter circuitry for the transmission of television signals according to analogue transmission standards H04N5/14 takes precedence

Abstract

Methods, and apparatus for carrying out the methods, are disclosed for synchronizing a plurality of RF transmitters that are supplied with a common digital information signal for carrier modulation and subsequent transmission on a common channel throughout a prescribed region, whereby the digital signal receivers within the region may receive transmissions on the channel from more than one transmitter. The method involves inserting reference signals into the data sent to the transmitters in order to place them into known states at specific times relative to the digital signals sent to them for transmission. As a result of this method, the digital signals transmitted by each of the transmitters will be identical to one another so that the receivers will be able to identify one received signal as the main signal and the others as echoes. If necessary, the signal transmitted by at least one of the synchronized transmitters may be delayed, such that identical digital signals received from at least two of the transmitters by receivers in the region will arrive at each receiver within a prescribed time window. The methods and apparatus also can be applied to one or a plurality of RF transmitters for purposes of synchronizing processes at the source of the signals and at the transmitters.

Claims

1. A method for synchronizing a plurality of digital RF transmitters that are supplied a common digital signal for RF modulation and subsequent transmission on a common channel throughout a prescribed region, whereby RF receivers within said region may receive transmissions on said channel from more than one transmitter, said method comprising the steps of:

generating a digital signal comprising informational data and formatting data;

inserting reference data into said digital signal;

transporting said digital signal with said reference data to said plurality of transmitters, each transmitter having channel coding, RF modulation and power amplification;

setting said channel coding of each transmitter at specific times into the same known states relative to said digital signal in response to receipt of said reference data;

at each transmitter, channel coding said digital signal, modulating the resultant channel coded digital signal onto a channel carrier and power amplifying the resultant modulated signal after the states have been set; and

transmitting the resultant amplified modulated signal at each transmitter,

whereby the modulated signals transmitted by said plurality of transmitters will be substantially identical to one another, so that said receivers in said region will be able to properly recover the informational data when receiving signals from multiple transmitters.

2-43. -43. (canceled)