Rotationally invariant non-coherent burst coding

• US 20080075176A1
• Filed: 09/25/2006
• Published: 03/27/2008
• Est. Priority Date: 09/25/2006
• Status: Active Grant

• Current Assignee: Alfred E. Mann Foundation For Scientific Research
• Original Assignee: Alfred E. Mann Foundation For Scientific Research
• Inventors: Karr, Lawrence J., Hess, Phillip B.
• Granted Patent: US 7,779,332 B2
• Time in Patent Office: Days
• US Class Current: 375/242
• CPC Class Codes: H03M 13/1505 Golay Codes
• CPC Class Codes: H03M 13/251 with block coding
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04J 13/16 Code allocation
• CPC Class Codes: H04L 1/0042 Encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit distortions, jitter, or to improve signal shape H04L1/0067 takes precedence
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0058 Block-coded modulation

Abstract

An apparatus, system and method can be arranged for coding and/or decoding with a phase invariant coding scheme that is useful for short burst signaling devices. 10-bit data is mapped into a 12-bit data with a non-coherent burst code mapper. A parity generator creates a 12-bit parity data to form a 24-bit extended binary Golay code from the 12-bit data. The values for selected bit fields in the 12-bit data and 12-bit parity data are swapped to generate I and Q data such that sensitivity to changes in rotational phase is removed. I and Q data can be used by a transmitter to transmit a rotationally-invariant signal. On receipt, I and Q signals can be recovered, reverse swapped to generate the parity and data signals, and remapped to recover the transmitted 10-bit data. The receiver can also be arranged to use a soft decoding method for improved signal integrity.

Claims

1. A method for coding a signal transmission using a phase invariant non-coherent burst coding scheme, the method comprising:

mapping a 10-bit data to a 12-bit data, wherein the mapping from 10-bit data space to 12-bit data space is determined by a 24-bit weight 12 template code;

generating a 12-bit parity for the 12-bit data using an extended binary Golay encoder, wherein the extended binary Golay encoder is arranged to provide a doubly even self-dual code;

identifying a first set of bit positions in the 12-bit data from a first portion of the 24-bit weight 12 template code;

identifying a second set of bit positions in the 12-bit parity from a second portion of the 24-bit weight 12 template code; and

swapping a first set of bit values occupying the first set of bit positions in the 12-bit data with a second set of bit values occupying the second set of bit positions in the 12-bit parity to provide a 24-bit coded signal, wherein a first 12-bit portion of the 24-bit coded signal corresponds to an in-phase portion of the signal transmission, and wherein a second 12-bit portion of the 24-bit coded signal corresponds to a quadrature phase portion of the signal transmission such that the 10-bit data is encoded in the signal transmission as a phase invariant non-coherent burst code.

2. The method of claim 1 further comprising:

mapping a second 10-bit data to a second 12-bit data, wherein the mapping from 10-bit data space to 12-bit data space is determined by the 24-bit weight 12 template code;

generating a second 12-bit parity for the second 12-bit data using the extended binary Golay encoder;

identifying a first set of bit positions in the second 12-bit data from the first portion of the 24-bit weight 12 template code;

identifying a second set of bit positions in the second 12-bit parity from the second portion of the 24-bit weight 12 template code;

swapping a first set of bit values occupying the first set of bit positions in the second 12-bit data with a second set of bit values occupying the second set of bit positions in the second 12-bit parity to provide a first 12-bit portion and a second 12-bit portion for a second 24-bit coded signal, wherein a first 12-bit portion of the second 24-bit coded signal corresponds to a second in-phase portion of the signal transmission, and wherein a second 12-bit portion of the second 24-bit coded signal corresponds to a second quadrature phase portion of the signal transmission such that the second 10-bit data is encoded in the second 24-bit coded signal; and

selecting a rotation for the second 24-bit coded signal in response to a 2-bit data, wherein the selected rotation corresponds to one of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, such that the second 24-bit coded signal is also encoded with the 2-bit data.

3. The method of claim 1, wherein the extended binary Golay encoder is arranged to apply a generator matrix (g) which is given by:

$g=\left[\begin{array}{cccccccccccccccccccccccc}1& 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 1& 0& 1& 1& 1& 0& 0& 0& 1& 0& 1\\ 0& 1& 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 0& 1& 1& 1& 0& 0& 0& 1& 0& 1& 1\\ 0& 0& 1& 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 1& 1& 0& 0& 0& 1& 0& 1& 1& 1\\ 0& 0& 0& 1& 0& 0& 0& 0& 0& 0& 0& 0& 1& 1& 1& 0& 0& 0& 1& 0& 1& 1& 0& 1\\ 0& 0& 0& 0& 1& 0& 0& 0& 0& 0& 0& 0& 1& 1& 0& 0& 0& 1& 0& 1& 1& 0& 1& 1\\ 0& 0& 0& 0& 0& 1& 0& 0& 0& 0& 0& 0& 1& 0& 0& 0& 1& 0& 1& 1& 0& 1& 1& 1\\ 0& 0& 0& 0& 0& 0& 1& 0& 0& 0& 0& 0& 0& 0& 0& 1& 0& 1& 1& 0& 1& 1& 1& 1\\ 0& 0& 0& 0& 0& 0& 0& 1& 0& 0& 0& 0& 0& 0& 1& 0& 1& 1& 0& 1& 1& 1& 0& 1\\ 0& 0& 0& 0& 0& 0& 0& 0& 1& 0& 0& 0& 0& 1& 0& 1& 1& 0& 1& 1& 1& 0& 0& 1\\ 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 0& 0& 1& 0& 1& 1& 0& 1& 1& 1& 0& 0& 0& 1\\ 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 0& 0& 1& 1& 0& 1& 1& 1& 0& 0& 0& 1& 1\\ 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 1& 1& 1& 1& 1& 1& 1& 1& 1& 1& 1& 0\end{array}\right]$

4. The method of claim 1, wherein the 24-bit weight 12 template code corresponds to 7FF800-hex.

5. A method for coding a signal transmission using a phase invariant non-coherent burst coding scheme, the method comprising:

generating a 12-bit data and a 12-bit parity from a 10-bit data, wherein the 12-bit data corresponds to a mapping between a 10-bit data space and a 12-bit data space based on a 24-bit weight 12 template code, and wherein the 12-bit parity corresponds to an extended binary Golay code that is associated with the 12-bit data;

identifying a first set of bit positions in the 12-bit data from a first portion of the 24-bit weight 12 template code;

identifying a second set of bit positions in the 12-bit parity from a second portion of the 24-bit weight 12 template code; and

swapping a first set of bit values occupying the first set of bit positions in the 12-bit data with a second set of bit values occupying the second set of bit positions in the 12-bit parity to provide a 24-bit coded signal, wherein a first 12-bit portion of the 24-bit coded signal corresponds to an in-phase portion of the signal transmission, and wherein a second 12-bit portion of the 24-bit coded signal corresponds to a quadrature phase portion of the signal transmission such that the 10-bit data is encoded in the signal transmission as a phase invariant non-coherent burst code.

6. The method of claim 5, wherein the step of generating further comprises:

retrieving the 12-bit data from a map that is indexed by the 10-bit data.

7. The method of claim 5, wherein the step of generating further comprises:

simultaneously retrieving the 12-bit data and the 12-bit parity data from a look-up table that is indexed by the 10-bit data.

8. The method of claim 5, wherein the step of generating further comprises:

determining the 12-bit parity data by multiplying the 12-bit data with a generator matrix (g), wherein the generator matrix corresponds to;

$g=\left[\begin{array}{cccccccccccccccccccccccc}1& 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 1& 0& 1& 1& 1& 0& 0& 0& 1& 0& 1\\ 0& 1& 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 0& 1& 1& 1& 0& 0& 0& 1& 0& 1& 1\\ 0& 0& 1& 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 1& 1& 0& 0& 0& 1& 0& 1& 1& 1\\ 0& 0& 0& 1& 0& 0& 0& 0& 0& 0& 0& 0& 1& 1& 1& 0& 0& 0& 1& 0& 1& 1& 0& 1\\ 0& 0& 0& 0& 1& 0& 0& 0& 0& 0& 0& 0& 1& 1& 0& 0& 0& 1& 0& 1& 1& 0& 1& 1\\ 0& 0& 0& 0& 0& 1& 0& 0& 0& 0& 0& 0& 1& 0& 0& 0& 1& 0& 1& 1& 0& 1& 1& 1\\ 0& 0& 0& 0& 0& 0& 1& 0& 0& 0& 0& 0& 0& 0& 0& 1& 0& 1& 1& 0& 1& 1& 1& 1\\ 0& 0& 0& 0& 0& 0& 0& 1& 0& 0& 0& 0& 0& 0& 1& 0& 1& 1& 0& 1& 1& 1& 0& 1\\ 0& 0& 0& 0& 0& 0& 0& 0& 1& 0& 0& 0& 0& 1& 0& 1& 1& 0& 1& 1& 1& 0& 0& 1\\ 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 0& 0& 1& 0& 1& 1& 0& 1& 1& 1& 0& 0& 0& 1\\ 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 0& 0& 1& 1& 0& 1& 1& 1& 0& 0& 0& 1& 1\\ 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 0& 1& 1& 1& 1& 1& 1& 1& 1& 1& 1& 1& 1& 0\end{array}\right]$

9. A method for decoding information from a signal transmission that is encoded with a phase invariant non-coherent burst coding scheme, the method comprising:

generating a plurality of pairs of 12-bit data and 12-bit parity data from a plurality of corresponding 10-bit data, wherein each 12-bit data corresponds to a mapping between a 10-bit data space and a 12-bit data space based on a 24-bit weight 12 template code, and wherein each 12-bit parity corresponds to an extended binary Golay code that is associated with the respective 12-bit data;

correlating the plurality of pairs of 12-bit data and 12-bit parity with a series of samples associated with the signal transmission, wherein the series of samples include a combination of signals and noise associated with the signal transmission; and

identifying a specific one of the plurality of 10-bit data that is associated with the highest correlation of the 12-bit data and the 12-bit parity with the series of samples associated with the signal transmission such that the specific one of the plurality of 10-bit data corresponds to the decoded information.

10. The method of claim 9, further comprising:

evaluating a phase angle associated with the correlation to identify an addition 2-bit data that is encoded in rotational phase of the signal transmission.

11. A method for decoding information from a signal transmission that is encoded with a non-coherent burst code, the method comprising:

derotating a series of baseband samples associated with the signal transmission into in-phase and quadrature-phase portions, wherein the series of baseband samples include a combination of signals and noise associated with the signal transmission, wherein the series of baseband samples has an unknown rotation angle, and wherein the derotated series of baseband samples are aligned to a nominal rotation angle that corresponds to at least one of 45 degrees, 135 degrees, 225 degrees, and 315 degrees;

generating a 24-bit coded signal by hard-limiting the derotated series of baseband samples;

identifying a first set of bit positions for a first 12-bit portion of the 24-bit coded signal from a first portion of a 24-bit weight 12 template code;

identifying a second set of bit positions for a second 12-bit portion of the 24-bit coded signal from a second portion of the 24-bit weight 12 template code;

swapping a first set of bit values in the first set of bit positions for the 24-bit coded signal with a second set of bit values occupying the second set of bit positions for the 24-bit coded signal to provide a 24-bit data;

decoding a 12-bit data from the 24-bit code using an extended binary Golay decoder; and

remapping the 12-bit data to a 10-bit output data, wherein the 12-bit data corresponds to a mapping from 10-bit data space to 12-bit data space, wherein the mapping between the 10-bit data space and the 12-bit data space is determined by the 24-bit weight 12 template code.

12. The method of claim 11, further comprising:

identifying a first rotational phase for a first one of the 10-bit output data that is received at a first instance of time;

identifying a second rotational phase for a second one of the 10-bit output data that is received at a second instance of time, wherein the second instance of time occurs after the first instance of time; and

decoding a 2-bit output data at the second instance of time from a difference between the first rotational phase and the second rotational phase.

13. The method of claim 12, wherein the first rotational phase is indicated with a first quadrant signal, the second rotational phase is indicated with a second quadrant signal, and wherein decoding comprises applying an exclusive OR operation on the first quadrant signal and the second quadrant signal.

14. The method of claim 11, further comprising:

mapping the 10-bit output data to a 24-bit code;

correlating the 24-bit code with the series of baseband samples to provide a phase signal;

identifying a first phase signal for a first one of the 10-bit output data that is received at a first instance of time;

identifying a second phase signal for a second one of the 10-bit output data that is received at a second instance of time, wherein the second instance of time occurs after the first instance of time; and

decoding a 2-bit output data at the second instance of time from a difference between the first phase signal and the second phase signal.

15. The method of claim 11, further comprising:

ranking a signal strength associated with each bit from the derotated series of baseband samples

identifying bit positions in the 24-bit coded signal corresponding to bits that have a lowest signal strength in the ranking;

creating a list of all possible values for the identified bit positions;

cycling through possible bit values for the identified bit positions until all permutations of bit values are exhausted, by;

selecting a next permutation of bit values from the list;

modifying the identified bit positions in the 24-bit coded signal with the selected bit values;

reverse swapping a first set of bit values in the first set of bit positions for the 24-bit data with a second set of bit values occupying the second set of bit positions for the 24-bit data to provide a second 24-bit data; and

correlating the second 24-bit data with the derotated series of baseband samples to provide a correlation result for the selected permutation of bit values;

ranking the correlation results; and

selecting the highest ranked correlation result for the decoded 12-bit data.

16. The method of claim 15, further comprising:

identifying a first rotational phase for a first one of the 10-bit output data that is received at a first instance of time;

identifying a second rotational phase for a second one of the 10-bit output data that is received at a second instance of time, wherein the second instance of time occurs after the first instance of time; and

decoding a 2-bit output data at the second instance of time from a difference between the first rotational phase and the second rotational phase.

17. The method of claim 16, wherein the first rotational phase is indicated with a first quadrant signal, the second rotational phase is indicated with a second quadrant signal, and wherein decoding comprises applying an exclusive OR operation on the first quadrant signal and the second quadrant signal.

18. The method of claim 16, wherein the first rotational phase is indicated from a first phase output of a correlator at the first instance of time, and wherein the second rotation phase is indicated from a second phase output of the correlator at the second instance of time.

19. A method for determining a phase invariant non-coherent burst coding mapping functions, the method comprising:

selecting a weight 12 code word;

generating a code list for all possible codes for the selected weight 12 code word;

cycling through the codes in the code list by;

selecting a code from the code list;

generating codes for all possible rotational phases for the selected code;

identifying conflicting codes that match the generated codes for the rotational phases of the selected code; and

blacklisting one of the selected code and the identified conflicting codes;

storing the mapping of data values for code words that are non-blacklisted.

20. The method of claim 19, wherein the mapping of data values is stored in at least one of:

a look-up table, a generator matrix, a memory, and a data mapper circuit.