Forward error correction in wideband digital RF transport systems

• US 20070195905A1
• Filed: 02/21/2006
• Published: 08/23/2007
• Est. Priority Date: 02/21/2006
• Status: Abandoned Application

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Schatz, Paul
• Application Number:
  US11/358,586
• Publication Number:
  US 20070195905A1
• Time in Patent Office: Days
• US Class Current: 375/265
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end

Abstract

Systems and methods for forward error correction in wideband digital RF transport systems is provided. In one embodiment, a method for transmitting digital data in a wideband digital RF transport system is provided. The method comprises receiving a first digital signal, wherein the digital signal includes a stream of digital RF packets, each digital RF packet comprising one or more data samples representing a digitized wideband RF spectrum; encoding error correction data into the stream of digital RF packets based on an error correction algorithm to produce a stream of modified packets; and transmitting a second digital signal comprised of the stream of modified packets via a communications medium.

Claims

1. A method for transmitting digital data in a wideband digital RF transport system, the method comprising:

receiving a first digital signal, wherein the digital signal includes a stream of digital RF packets, each digital RF packet comprising one or more data samples representing a digitized wideband RF spectrum;

encoding error correction data into the stream of digital RF packets based on an error correction algorithm to produce a stream of modified packets; and

transmitting a second digital signal comprised of the stream of modified packets via a communications medium.

2. The method of claim 1, wherein receiving a first digital signal comprises receiving a signal modulated based on one or more of an Advanced Mobile Phone System (AMPS) modulation protocol, a code division multiple access (CDMA) modulation protocol, a Wide-band CDMA (WCDMA) modulation protocol, a time division multiple access (TDMA) modulation protocol, a Global System for Mobile communications (GSM) modulation protocol, a Cellular Digital Packet Data (CDPD) modulation protocol, an Enhanced Data rates for GSM Evolution (EDGE) modulation protocol, a General Packet Radio Service (GPRS) modulation protocol, an Integrated Digital Enhanced Network (iDEN) modulation protocol, and an Orthogonal Frequency Division Multiplexing (OFDM) modulation protocol.

3. The method of claim. 1, wherein transmitting a second digital signal further comprises transmitting the second digital signal via one or more of fiber optic cable, wire cable, coaxial cable, twisted pair cable, and a wireless communication link.

4. The method of claim 1, wherein encoding error correction data into the stream of digital RF packets further comprises executing a error correction algorithm based on one or more of block coding, convolutional coding, turbo coding, Reed-Solomon coding, BCH coding, Hamming coding, a Viterbi algorithm, 1xEV-DO coding, check bits, digital fountain code, differential space-time code, erasure codes, binary Golay codes, ternary Golay codes, Hagelbarger code, a low-density parity-check (LDPC) code, Reed-Muller code, and space-time trellis codes (STTCs).

5. The method of claim 1, further comprising one or both of:

multiplexing the stream of digital RF packets into a serialized stream of digital RF packets; and

multiplexing the stream of modified packets into a serialized stream of modified packets.

6. The method of claim 1, further comprising:

digitally up-converting the stream of digital RF packets from a baseband modulation frequency to a broadcast channel frequency.

7. The method of claim 1, further comprising:

receiving the second digital signal from the communications medium; and

decoding the stream of modified packets to determine whether the stream of modified packets arrived error-free.

8. The method of claim 7, wherein, when a modified packet of the stream of modified packets is determined to have arrived error-free, the method further comprises:

stripping error correction data from the modified packet; and

outputting a restored digital RF packet.

9. The method of claim 7, wherein, when a modified packet of the stream of modified packets is determined to have arrived with one or more errors, the method further comprises:

reconstructing a digital RF packet based on the error correction data encoded in the modified packet; and

outputting a corrected digital RF packet.

10. The method of claim 7, further comprising:

generating an analog wideband RF spectrum signal based on decoded digital RF packet from the second digital signal.

11. The method of claim 7, further comprising one or both of:

de-multiplexing the decoded stream of modified packets into a digital wideband signal; and

de-multiplexing the stream of modified packets into a digital wideband signal.

12. The method of claim 7, further comprising one or both of:

digitally down-converting decoded digital RF packets to a baseband modulation frequency.

13. A computer-readable medium having computer-executable program instructions for a method for communicating digital RF data in a communications network, the method comprising:

inputting a stream of digital RF packets, wherein each digital RF packet comprises one or more data samples representing a digitized wideband RF spectrum;

encoding each digital RF packet of the stream of digital RF packets with error correction data; and

outputting a stream of error correction encoded data packets based on the digital RF packets.

14. The computer-readable medium of claim 13, wherein encoding each digital RF packet of the stream of digital RF packets further comprises executing a error correction algorithm based on one or more of block coding, convolutional coding, turbo coding, Reed-Solomon coding, BCH coding, Hamming coding, a Viterbi algorithm, 1xEV-DO coding, check bits, digital fountain code, differential space-time code, erasure codes, binary Golay codes, ternary Golay codes, Hagelbarger code, a low-density parity-check (LDPC) code, Reed-Muller code, and space-time trellis codes (STTCs).

15. The computer-readable medium of claim 13 further comprising applying a pre-emphasis function to the stream of error correction encoded data packets.

16. A computer-readable medium having computer-executable program instructions for a method for communicating digital RF data in a communications network, the method comprising:

inputting a stream of data packets, wherein each packet comprises one or more data samples representing a digitized wideband RF spectrum encoded with error correction data;

decoding each data packet to determine whether the one or more data samples were received without errors; and

outputting a stream digital RF packets, wherein each digital RF packet comprises one or more data samples representing the digitized wideband RF spectrum.

17. The computer-readable medium of claim 16, wherein decoding each data packet to determine whether the one or more data samples were received without errors further comprises executing a error correction algorithm based on one or more of block coding, convolutional coding, turbo coding, Reed-Solomon coding, BCH coding, Hamming coding, a Viterbi algorithm, 1xEV-DO coding, check bits, digital fountain code, differential space-time code, erasure codes, binary Golay codes, ternary Golay codes, Hagelbarger code, a low-density parity-check (LDPC) code, Reed-Muller code, and space-time trellis codes (STTCs).

18. The computer-readable medium of claim 16 further comprising applying a receive equalization function to the stream of data packets.

19. A communication network, the network comprising:

means for encoding a stream of digital RF packets with error correction data based on a forward error correction algorithm, wherein each digital RF packet of the stream of digital RF packets comprises one or more data samples representing a digitized wideband RF spectrum, the means for encoding further adapted to output a stream of error correction encoded digital RF packets; and

means for communicating a digital signal to a communication medium, the means for communicating responsive to the means for encoding, wherein the means for communication a digital signal is adapted to communicate the stream of error correction encoded packets to the communication medium.

20. A communications network comprising, the network comprising:

means for receiving a digital signal, wherein the digital signal comprises a stream of error correction encoded digital RF packets; and

means for decoding the stream of error correction encoded digital RF packets based on a forward error correction algorithm, the means for decoding further adapted to extract from each digital RF packet of the stream of error correction encoded digital RF packets one or more data samples representing a digitized wideband RF spectrum.

21. The network of claim 20, wherein the means for decoding is further adapted to determine whether each digital RF packet of the stream of error correction encoded digital RF packets was received error-free by the means for receiving a digital signal.

22. The network of claim 21 wherein, when the means for decoding determines a digital RF packet of the stream of error correction encoded digital RF packets was received error-free, the means for decoding is further adapted to:

remove error correction data from the digital RF packet; and

output a restored digital RF packet.

23. The network of claim 21 wherein when the means for decoding determines a digital RF packet of the stream of error correction encoded digital RF packets includes one or more error, the means for decoding is further adapted to:

reconstruct one or more data samples representing a digitized wideband RF spectrum based on the error correction data encoded in the error correction encoded digital RF packets; and

outputting a corrected digital RF packet.

24. A wideband digital RF transport system, the system comprising:

a first communications network segment adapted to incorporate forward error correction data into one or more digitized data samples based on an error correction encoding algorithm, wherein the one or more digitized data samples represent a wideband RF spectrum signal, the first communications network segment further adapted to output a digital signal representing the forward error correction encoded data samples;

a second communications network segment adapted to receive the digital signal and apply an error correction decoding algorithm to the error correction encoded data samples; and

a communications medium coupled to the first communications network segment and the second communications network segment, the communications medium adapted to communicate the digital signal from the first communications network segment to the second communications network segment.

25. The system of claim 24, wherein the first communications network segment includes a base station comprising:

a call processing software module adapted to receive signals from an upstream communications network and generate digital RF packets based on the signals, the digital RF packets including one or more data samples representing a digitized wideband RF spectrum; and

a forward error correction encoder adapted to receive the digital RF packets and incorporate forward error correction data into the digital RF packets.

26. The system of claim 25, the base station further comprising:

at least one digital up converter adapted to receive the digital RF packets generated by the call processing software, the digital up converter further adapted to remodulate the digital RF packets from a baseband frequency to a broadcast channel frequency

27. The system of claim 25, the base station further comprising:

a wideband signal multiplexer adapted to convert a wideband digital RF signal into a serialized stream of digital RF packets; and

a signal transmitter coupled to the wideband signal multiplexer and adapted to transmit the serialized stream of digital RF packets via a communications medium.

28. The system of claim 25, wherein the forward error correction encoder is adapted to implement an error correction algorithm based on one or more of block coding, convolutional coding, turbo coding, Reed-Solomon coding, BCH coding, Hamming coding, a Viterbi algorithm, 1xEV-DO coding, check bits, digital fountain code, differential space-time code, erasure codes, binary Golay codes, ternary Golay codes, Hagelbarger code, a low-density parity-check (LDPC) code, Reed-Muller code, and space-time trellis codes (STTCs).

29. The system of claim 25, the base station further comprising:

a signal receiver adapted to receive a second digital signal from the communications medium, the second digital signal including a stream of error correction encoded digital RF packets having one or more data samples representing a digitized wideband RF spectrum; and

a forward error correction decoder coupled to the signal receiver and adapted to determine whether the error correction encoded data samples were received error free.

30. The system of claim 25, the base station further comprising:

at least one digital down converter adapted to receive decoded digital RF packets from the a forward error correction decoder and remodulate the digital RF packets to a baseband frequency.

31. The system of claim 24, wherein the second communications network segment includes a remote unit comprising:

a signal receiver adapted to receive the digital signal from the communications medium; and

a forward error correction decoder coupled to the signal receiver and adapted to decode the error correction encoded data samples, wherein the forward error correction decoder is further adapted to determine whether the error correction encoded data samples were received error free based on an error correction algorithm.

32. The system of claim 31, the remote unit further comrprises:

a digital to analog converter adapted to convert decoded data samples into a wideband RF spectrum signal; and

a wireless RF transmitter adapted to wirelessly broadcast the wideband RF spectrum signal.

33. The system of claim 31, the remote unit further comrprises:

a forward error correction encoder adapted to receive digital RF packets and incorporate forward error correction data into the digital RF packets; and

a signal transmitter coupled to communicate with the forward error correction encoder and adapted to transmit forward error correction encoded digital RF packets via the communications medium.

34. The system of claim 24, the first communications network segment further comprising a pre-emphasis function, the pre-emphasis network adapted to boosts high frequency components of the one or more digitized data samples.

35. The system of claim 24, the second communications network segment further comprising a receive equalization function, the receive equalization function adapted to implement a high pass filter on the digital signal and amplify the digital signal.