| US 7,529,487 B2 | ||
| System and method for transmitting data on return path of a cable television system | ||
| Frank H. Levinson, The Edge on Cairnhill, Calif. (US); Gerald F. Sage, Chico, Calif. (US); Arthur Michael Lawson, Morgan Hill, Calif. (US); and Willem A. Mostert, Issaquah, Wash. (US) | ||
| Assigned to Finisar Corporation, Sunnyvale, Calif. (US) | ||
| Filed on Aug. 13, 2007, as Appl. No. 11/838,167. | ||
| Application 11/838167 is a division of application No. 09/735710, filed on Dec. 12, 2000, granted, now 7,257,328. | ||
| Claims priority of provisional application 60/170413, filed on Dec. 13, 1999. | ||
| Prior Publication US 2007/0277213 A1, Nov. 29, 2007 | ||
| Int. Cl. H04B 10/00 (2006.01) | ||
| U.S. Cl. 398—135 | 2 Claims |
| 1. A return path transmitter for use in conjunction with a local system that generates an analog RF data signal to be conveyed
to a head end system, the return path transmitter comprising:
an optical signal receiver configured to receive a digital optical signal and generate therefrom a first digitized RF data
stream and a sample clock, wherein the optical signal receiver is further configured to demultiplex data within the received
digital optical signal into a first digitized RF data stream and a first non-RF data stream;
an RF signal receiver, coupled to the optical signal receiver, configured to receive and convert the analog RF data signal
into a second digitized RF data stream of digitized RF data samples at a rate determined by the sample clock;
a summing circuit configured to mathematically sum the first and second digitized RF data streams so as to generate a third
digitized RF data stream;
an optical transmitter configured to convert an output data stream into a serialized optical data signal for transmission
over an optical fiber, the output data stream including the third digitized RF data stream;
a data port for receiving a second non-RF data stream from a digital data source external to the return path transmitter,
the second non-RF data stream having a data rate of at least 5 Mb/s;
a full duplex drop and add circuit for extracting a portion of the first non-RF data stream and for replacing the extracted
portion of the first non-RF data stream with the second non-RF data stream so as to generate a third non-RF data stream;
a multiplexor coupled to the summing circuit and the full duplex drop and add circuit to receive the third digitized RF data
stream and the third non-RF data stream and to output a combined data stream; and
the output data stream converted by the optical transmitter includes the combined data stream.
|