Rain fade mitigation in a data transmission system

• US 6,307,833 B1
• Filed: 02/16/1999
• Issued: 10/23/2001
• Est. Priority Date: 02/16/1999
• Status: Expired due to Term

• Current Assignee: Telesat Network Services, Inc. (MHR Holdings LLC (New York))
• Original Assignee: Loral Cyberstar, Inc. (MHR Holdings LLC (New York))
• Inventors: Barker, Keith R., Rafter, Mark T.
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): TRINH, DUNG N
• Application Number:
  US09/249,895
• Time in Patent Office: 980 Days
• Field of Search: 370/216, 370/317, 370/350, 370/519, 370/428, 370/349, 455/503, 455/504, 455/505, 455/506, 455/519, 375/347, 714/746, 714/774, 714/786
• US Class Current: 370/216
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/18523 Satellite systems for providing broadcast service to terrestrial stations, i.e. broadcast satellite service arrangements specially adapted for satellite broadcast receiving H04H40/90; picture transmission via satellite H04N1/00103; television transmission via satellite H04N7/20

Abstract

Rain fade mitigation methods and data broadcast systems that provide improved performance in a rain fade environment. The systems distribute data derived from a transmitting processor by way of a data distribution system to one or more receivers located at remote locations. The transmitting processor may include forward error correction processing software that is used to add forward error correction bits to data packets to be transmitted. When error correction bits are added to the data prior to transmission, the receivers include forward error correction software that processes the received data packets to reconstruct the original data. Data packets with or without error correcting bits may be transmitted two times to the remote locations, which times are separated by a time delay having a duration that is related to a rain fade event, which time delay is sufficient to allow data reconstruction in the presence of the rain fade event. The data packets may also be transmitted to the remote locations at a relatively slow transmission rate such that the time required to transmit the data to the one or more remote locations is greater than or equal to the time necessary to transmit the data plus the amount of time equal to an average rain fade event. The data packets are received at the remote locations and appropriately processed to reconstruct the original data.

Claims

1. A data broadcast system for distributing data to one or more remote locations in a rain fade environment, comprising:

a transmitting processor for forming data packets comprising data to be transmitted and forward error correction bits;

a data distribution system for transmitting the data packets to one or more receivers located at remote locations, which data packets are transmitted at a relatively slow transmission rate such that the time required to transmit the data to the one or more receivers is greater than or equal to the time necessary to transmit the data plus an amount of time sufficient to allow data reconstruction in the presence of a rain fade event, and

the receivers receiving the data packets and processing the received data packets using forward error correction processing to reconstruct the original data.

2. The system recited in claim 1 wherein the data broadcast system comprises a satellite.

3. The system recited in claim 1 wherein the data broadcast system comprises an RF data broadcast system.

4. The system recited in claim 1 wherein the number of forward error correction bits added to each packet is configurable.

5. A rain fade mitigation method for distributing data to one or more remote locations in a rain fade environment, comprising the steps of:

forming data packets comprising data to be transmitted and forward error correction bits;

transmitting the data packets and forward error correction bits to one or more remote locations, which data packets are transmitted at a relatively slow transmission rate such that the time required to transmit the data to the one or more receivers is greater than or equal to the time necessary to transmit the data plus an amount of time sufficient to allow data reconstruction in the presence of a rain fade event;

receiving the data packets and forward error correction bits at the one or more remote locations; and

forward error correction processing the received data pas packet and forward error correction bits to reconstruct the original data.

6. The method recited in claim 5 wherein the number or forward error correction bits added to each packet is configurable.