Data processing apparatus and method for use in a 0.5K mode interleaver in a digital video broadcasting standard including DVB-Terrestrial2

• US 8,306,137 B2
• Filed: 10/24/2008
• Issued: 11/06/2012
• Est. Priority Date: 10/30/2007
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Atungsiri, Samuel Asanbeng, Taylor, Matthew Paul Athol, Wilson, John Nicholas
• Primary Examiner(s): Torres, Juan A
• Application Number:
  US12/740,014
• Publication Number:
  US 20100296593A1
• Time in Patent Office: 1,474 Days
• Field of Search: 375/260, 375/230, 455/59, 370/203
• US Class Current: 375/260
• CPC Class Codes: G11C 19/00 Digital stores in which the information is moved stepwise, e.g. shift registers
• CPC Class Codes: H03M 13/276 Interleaving address generation
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 27/14 Demodulator circuits; Receiver circuits
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals

Abstract

A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit.

Claims

1. A data processing apparatus operable to map input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol, the data processing apparatus comprising:

an interleaver operable to read-into a memory the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals, and to read-out of the memory the data symbols for the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on the sub-carrier signals, and

an address generator operable to generate the set of addresses, the addresses being generated for the input symbols to indicate the sub-carrier signals onto which the data symbols are to be mapped, the address generator comprising;

a linear feedback shift register including a predetermined number of register stages and being operable to generate a pseudo-random bit sequence in accordance with a generator polynomial,

a permutation circuit operable to receive the content of the shift register stages and to permute the bits present in the register stages in accordance with a permutation order to form an address of one of the OFDM sub-carriers, and

a control unit operable in combination with an address check circuit to re-generate an address when a generated address exceeds a predetermined maximum valid address, wherein

the predetermined maximum valid address is approximately five hundred, and

the linear feedback shift register has eight register stages with a generator polynomial for the linear feedback shift register of

R′

_i[7]=R′

_i-1[0]⊕

R′

_i-1[1]⊕

R′

_i-1[5]⊕

R′

_i-1[6]

and the permutation order forms, with an additional bit, a nine bit address R_i[n] for the i-th data symbol from the bit present in the n-th register stage R′

_i[n] in accordance with the table;

2. The data processing apparatus as claimed in claim 1, wherein the interleaver is operable to perform the mapping such that pairs of adjacent data symbols are mapped onto adjacent sub-carrier signals to the effect that data symbols are interleaved pair by pair onto the sub-carrier signals.

3. The data processing apparatus as claimed in claim 1, wherein the predetermined maximum valid address is a value substantially between three hundred and five hundred and twelve.

4. The data processing apparatus as claimed in claim 1, wherein the OFDM symbol includes pilot sub-carriers, which are arranged to carry known symbols, and the predetermined maximum valid address depends on a number of the pilot sub-carrier symbols present in the OFDM symbol.

5. The data processing apparatus as claimed in claim 1, wherein the predetermined maximum valid address is a value equal to three hundred and seventy eight.

6. The data processing apparatus as claimed in claim 1, wherein the interleaver memory is operable to effect the mapping of the input data symbols onto the sub-carrier signals for even OFDM symbols by reading in the data symbols according to the set of addresses generated by the address generator and reading out in a sequential order, and for odd OFDM symbols by reading in the symbols into the memory in a sequential order and reading out the data symbols from the memory in accordance with the set of addresses generated by the address generator.

7. The data processing apparatus as claimed in claim 1, wherein the sub-carriers of the OFDM symbols are half or less than half a maximum number of sub-carriers in the OFDM symbols of any of a plurality of operating modes, and the input data symbols include first sets of input data symbols for mapping onto even OFDM symbols and second sets of input data symbols for mapping onto odd OFDM symbols, and the data processing apparatus is operable to interleave the input data symbols from both first and second sets in accordance with an odd interleaving process,

the odd interleaving process including

writing the first sets of input data symbols into a first part of the interleaver memory in accordance with a sequential order of the first sets of input data symbols,

reading out the first sets of input data symbols from the first part of the interleaver memory on to the sub-carrier signals of the even OFDM symbols in accordance with an order defined by the set of addresses generated with one of the permutation codes of the sequence,

writing the second set of input data symbols into a second part of the interleaver memory in accordance with a sequential order of the second sets of input data symbols, and

reading out the second sets of input data symbols from the second part of the interleaver memory on to the sub-carrier signals of the odd OFDM symbols in accordance with an order defined by the set of addresses generated with another of the permutation codes of the sequence.

8. The data processing apparatus as claimed in claim 7, wherein the permutation circuit is operable to change the permutation code, which permutes the order of the bits of the register stages to form the addresses from one OFDM symbol to another.

9. The data processing apparatus as claimed in claim 7, wherein the permutation circuit is operable to cycle through a sequence of different permutation codes for successive OFDM symbols.

10. The data processing apparatus as claimed in claim 7, wherein the sequence of permutation codes comprises two permutation codes, which are:

11. A data processing apparatus operable to map symbols received from a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol into an output symbol stream, the data processing apparatus comprising:

a de-interleaver operable to read-into a memory the predetermined number of data symbols from the OFDM sub-carrier signals, and to read-out of the memory the data symbols into the output symbol stream to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are de-interleaved from the OFDM sub-carrier signals, and

an address generator operable to generate the set of addresses, the addresses being generated for the received data symbols to indicate the OFDM sub-carrier signals from which the received data symbols are to be mapped into the output symbol stream, the address generator comprising;

a linear feedback shift register including a predetermined number of register stages and being operable to generate a pseudo-random bit sequence in accordance with a generator polynomial,

a permutation circuit operable to receive the content of the shift register stages and to permute the bits present in the register stages in accordance with a permutation order to form an address of one of the OFDM sub-carriers, and

a control unit operable in combination with an address check circuit to re-generate an address when a generated address exceeds a predetermined maximum valid address, wherein

the predetermined maximum valid address is approximately five hundred, and

the linear feedback shift register has eight register stages with a generator polynomial for the linear feedback shift register of R′

_i[7]=R′

_i-1[0]⊕

R′

_i-1[1]⊕

R′

_i-1[5]⊕

R′

_i-1[6], and the permutation order forms, with an additional bit, a nine bit address R_i[n] for the i-th data symbol from the bit present in the n-th register stage R_i[n] in accordance with the table;

12. The data processing apparatus as claimed in claim 11, wherein the de-interleaver is operable to perform the mapping such that pairs of adjacent data symbols are mapped onto adjacent sub-carrier signals to the effect that data symbols are interleaved pair by pair onto the sub-carrier signals.

13. The data processing apparatus as claimed in claim 11, wherein the predetermined maximum valid address is a value substantially between three hundred and five hundred and twelve.

14. The data processing apparatus as claimed in claim 11, wherein the OFDM symbol includes pilot sub-carriers, which are arranged to carry known symbols, and the predetermined maximum valid address depends on a number of the pilot sub-carrier symbols present in the OFDM symbol.

15. The data processing apparatus as claimed in claim 11, wherein the predetermined maximum valid address is a value equal to three hundred and seventy eight.

16. The data processing apparatus as claimed in claim 11, wherein the de-interleaver memory is arranged to effect the mapping of the received data symbols from the sub-carrier signals onto the output data stream for even OFDM symbols by reading in the data symbols according to a sequential order and reading out the data symbols from memory according to the set of addresses generated by the address generator, and for odd OFDM symbols by reading in the symbols into the memory in accordance with the set of addresses generated by the address generator and reading out the data symbols from the memory in accordance with a sequential order.

17. The data processing apparatus as claimed in claim 11, wherein the sub-carriers of the OFDM symbols are half or less than half a maximum number of sub-carriers in the OFDM symbols of any of a plurality of operating modes, and the data symbols include first sets of data symbols received from even OFDM symbols and second sets of data symbols received from odd OFDM symbols, and the data processing apparatus is operable to de-interleave the first and second sets of data symbols into the output data stream in accordance with an odd interleaving process,

the odd interleaving process including:

writing the first sets of data symbols received from the sub-carriers of the even OFDM symbols into a first part of the interleaver memory in accordance with an order determined by the set of addresses generated with one of the permutation codes of the sequence,

reading out the first sets of data symbols from the first part of the interleaver memory into the output data stream in accordance with a sequential order of the first sets of input data symbols,

writing the second set of data symbols received from the sub-carriers of the odd OFDM symbols into a second part of the interleaver memory in accordance with an order defined by the set of addresses generated with another of the permutation codes of the sequence, and

reading out the second sets of data symbols from the second part of the interleaver memory into the output data stream in accordance with a sequential order of the second sets of input data symbols.

18. The data processing apparatus as claimed in claim 17, wherein the permutation circuit is operable to change the permutation code, which permutes the order of the bits of the register stages to form the addresses from one OFDM symbol to another.

19. The data processing apparatus as claimed in claim 17, wherein the permutation circuit is operable to cycle through a sequence of different permutation codes for successive OFDM symbols.

20. The data processing apparatus as claimed in claim 19, wherein the sequence of permutation codes comprises two permutation codes, which are:

21. A method of mapping input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol, the method comprising:

reading-into a memory the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals,

reading-out of the memory the data symbols for the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on the sub-carrier signals, and

generating the set of addresses, the addresses being generated for the input symbols to indicate the sub-carrier signals onto which the data symbols are to be mapped, the generating the set of addresses comprising;

using a linear feedback shift register including a predetermined number of register stages to generate a pseudo-random bit sequence in accordance with a generator polynomial,

using a permutation circuit operable to receive the content of the shift register stages to permute the bits present in the register stages in accordance with a permutation order to form an address, and

re-generating an address when a generated address exceeds a predetermined maximum valid address, wherein

the predetermined maximum valid address is approximately five hundred, and

the linear feedback shift register has eight register stages with a generator polynomial for the linear feedback shift register of R′

_i[7]=R′

_i-1[0]⊕

R′

_i-1[1]⊕

R′

_i-1[5]⊕

R′

_i-1[6], and the permutation order forms, with an additional bit, a nine bit address R_i[n] for the i-th data symbol from the bit present in the n-th register stage R;

[n] in accordance with the table;

22. The method as claimed in claim 21, wherein the mapping is such that pairs of adjacent data symbols are mapped onto adjacent sub-carrier signals to the effect that data symbols are interleaved pair by pair onto the sub-carrier signals.

23. The method as claimed in claim 21, wherein the predetermined maximum valid address is a value substantially between three hundred and five hundred and twelve.

24. The method as claimed in claim 21, wherein the OFDM symbol includes pilot sub-carriers, which are arranged to carry known symbols, and the predetermined maximum valid address depends on a number of the pilot sub-carrier symbols present in the OFDM symbol.

25. The method as claimed in claim 21, wherein the predetermined maximum valid address is a value equal to three hundred and seventy eight.

26. The method as claimed in claim 21, wherein the reading-into the interleaver memory the input data symbols, and the reading-out of the interleaver memory the input data symbols for mapping onto the OFDM sub-carrier signals to effect the mapping, includes

for even OFDM symbols, reading in the data symbols according to the set of addresses generated by the address generator and reading out in a sequential order, and

for odd OFDM symbols, reading in the symbols into the interleaver memory in a sequential order and reading out the data symbols from the interleaver memory in accordance with the set of addresses generated by the address generator.

27. The method as claimed in claim 21, wherein the sub-carriers of the OFDM symbols are half or less than half a maximum number of sub-carriers in the OFDM symbols of any of a plurality of operating modes, the method comprising:

dividing the input data symbols into first sets of input data symbols for mapping onto even OFDM symbols and second sets of input data symbols for mapping onto odd OFDM symbols, and

interleaving the input data symbols from both rust and second sets in accordance with an odd interleaving process comprising;

writing the first sets of input data symbols into a first part of the interleaver memory in accordance with a sequential order of the rust sets of input data symbols,

reading out the first sets of input data symbols from the first part of the interleaver memory on to the sub-carrier signals of the even OFDM symbols in accordance with an order defined by the set of addresses generated with one of the permutation codes of the sequence,

writing the second set of input data symbols into a second part of the interleaver memory in accordance with a sequential order of the second sets of input data symbols, and

reading out the second sets of input data symbols from the second part of the interleaver memory on to the sub-carrier signals of the odd OFDM symbols in accordance with an order defined by the set of addresses generated with another of the permutation codes of the sequence.

28. The method as claimed in claim 27, wherein the using a permutation circuit to receive the content of the shift register stages and permuting the bits present in the register stages in accordance with a permutation code to form an address, includes changing the permutation code, which permutes the order of the bits of the register stages to form the addresses, from one OFDM symbol to another.

29. The method as claimed in claim 27, wherein the changing the permutation code, which permutes the order of the bits of the register stages to form the addresses, from one OFDM symbol to another includes cycling through a sequence of different permutation codes for successive OFDM symbols.

30. The method as claimed in claim 29, wherein the sequence of permutation codes comprises two permutation codes, which are:

31. A method of mapping symbols received from a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol into an output symbol stream, the method comprising:

reading-into a memory the predetermined number of data symbols from the OFDM sub-carrier signals,

reading-out of the memory the data symbols into the output symbol stream to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are de-interleaved from the OFDM sub-carrier signals, and

generating the set of addresses, the addresses being generated for each of the received symbols to indicate the OFDM sub-carrier signals from which the received data symbols are to be mapped into the output symbol stream, the generating the set of addresses comprising;

using a linear feedback shift register including a predetermined number of register stages to generate a pseudo-random bit sequence in accordance with a generator polynomial,

using a permutation circuit to receive the content of the shift register stages and to permute the bits present in the register stages in accordance with a permutation order to form an address, and

re-generating an address when a generated address exceeds a predetermined maximum valid address, wherein

the predetermined maximum valid address is approximately five hundred, and

the linear feedback shift register has eight register stages with a generator polynomial for the linear feedback shift register of R′

_i[7]=R′

_i-1[0]⊕

R′

_i-1[1]⊕

R′

_i-1[5]⊕

R′

_i-1[6], and the permutation order forms, with an additional bit, a nine bit address R_i[n] for the i-th data symbol from the bit present in the n-th register stage R′

_i[n] in accordance with the table;

32. The method as claimed in claim 31, wherein the mapping is such that pairs of data input symbols are mapped onto adjacent sub-carrier signals to the effect that data symbols are interleaved pair by pair onto the sub-carrier signals.

33. The method as claimed in claim 31, wherein the predetermined maximum valid address is a value substantially between three hundred and five hundred and twelve.

34. The method as claimed in claim 31, wherein the OFDM symbol includes pilot sub-carriers, which are arranged to carry known symbols, and the predetermined maximum valid address depends on a number of the pilot sub-carrier symbols present in the OFDM symbol.

35. The method as claimed in claim 31, wherein the predetermined maximum valid address is a value equal to three hundred and seventy eight.

36. The method as claimed in claim 31, wherein the reading-into the interleaver memory the predetermined number of data symbols from the OFDM sub-carrier signals, and the reading-out of the interleaver memory the data symbols into the output symbol stream to effect the mapping, includes:

for even OFDM symbols, reading in the data symbols according to a sequential order, and

reading out the data symbols from the interleaver memory according to the set of addresses generated by the address generator, and

for odd OFDM symbols, by reading in the data symbols into the leaver memory in accordance with the set of addresses generated by the address generator, and

reading out the data symbols from the memory in accordance with a sequential order.

37. The method as claimed in claim 31, wherein the sub-carriers of the OFDM symbols are half or less than half a maximum number of sub-carriers in the OFDM symbols of any of a plurality of operating modes, the method comprising:

receiving first sets of data symbols from even OFDM symbols and second sets of data symbols from odd OFDM symbols, and the reading-into the interleaver memory the data symbols received from the OFDM sub-carrier signals, and the reading-out of the interleaver memory the data symbols into the output symbol stream to effect the mapping is in accordance with an odd interleaving process, the odd interleaving process including;

writing the first sets of data symbols received from the sub-carriers of the even OFDM symbols into a first part of the interleaver memory in accordance with an order determined by the set of addresses generated with one of the permutation codes of the sequence,

reading out the first sets of data symbols from the first part of the interleaver memory into the output data stream in accordance with a sequential order of the first sets of input data symbols,

writing the second set of data symbols received from the sub-carriers of the odd OFDM symbols into a second part of the interleaver memory in accordance with an order defined by the set of addresses generated with another of the permutation codes of the sequence, and

reading out the second sets of data symbols from the second part of the interleaver memory into the output data stream in accordance with a sequential order of the second sets of input data symbols.

38. The method as claimed in claim 37, wherein the using a permutation circuit to receive the content of the shift register stages and permuting the bits present in the register stages in accordance with the permutation code to form an address, includes changing the permutation code, which permutes the order of the bits of the register stages to form the addresses, from one OFDM symbol to another.

39. The method as claimed in claim 37, wherein the changing the permutation code, which permutes the order of the bits of the register stages to form the addresses, from one OFDM symbol to another includes cycling through a sequence of different permutation codes for successive OFDM symbols.

40. The method as claimed in claim 39, wherein the sequence of permutation codes comprises two permutation codes, which are:

41. An address generator for use with transmission or reception of data symbols interleaved onto sub-carriers of an Orthogonal Frequency Division Multiplexed symbol, the address generator being operable to generate a set of addresses, the addresses being generated for the data symbols to indicate the sub-carrier signals onto which the data symbols are to be mapped, the address generator comprising:

a linear feedback shift register including a predetermined number of register stages and being operable to generate a pseudo-random bit sequence in accordance with a generator polynomial,

a permutation circuit operable to receive the content of the shift register stages and to permute the bits present in the register stages in accordance with a permutation order to form an address, and

a control unit operable in combination with an address check circuit to re-generate an address when a generated address exceeds a predetermined maximum valid address, wherein

the predetermined maximum valid address is approximately five hundred, and

the linear feedback shift register has eight register stages with a generator polynomial for the linear feedback shift register of R′

_i[7]=R′

_i-1[0]⊕

R′

_i-1[1]⊕

R′

_i-1[5]⊕

R′

_i-1[6], and the permutation order forms, with an additional bit, a nine bit address R_i[n] for the i-th data symbol from the bit present in the n-th register stage R′

_i[n] in accordance with the table;

42. A transmitter for transmitting data using Orthogonal Frequency Division Multiplexing (OFDM), the transmitter including a data processing apparatus operable to map input data symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol, the data processing apparatus comprising:

an interleaver operable to read-into an interleaver memory the predetermined number of input data symbols for mapping onto the OFDM sub-carrier signals, and to read-out of the interleaver memory the data symbols for the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on the sub-carrier signals,

an address generator operable to generate the set of addresses, the addresses being generated for the input data symbols to indicate the sub-carrier signals onto which the data symbols are to be mapped, the address generator comprising;

a linear feedback shift register including a predetermined number of register stages and being operable to generate a pseudo-random bit sequence in accordance with a generator polynomial,

a permutation circuit operable to receive the content of the shift register stages and to permute the bits present in the register stages in accordance with a permutation code to form an address of one of the OFDM sub-carriers, and

a control unit operable in combination with an address check circuit to regenerate an address when a generated address exceeds a predetermined maximum valid address, wherein

the predetermined maximum valid address is approximately five hundred, and

the linear feedback shift register has eight register stages with a generator polynomial for the linear feedback shift register of R′

_i-1[7]=R′

_i-1[0]⊕

R′

_i-1[1]⊕

R′

_i-1[5]⊕

R′

_i-1[6] and the permutation order forms, with an additional bit, a nine bit address R_i[n] for the i-th data symbol from the bit present in the n-th register stage R′

_i[n] in accordance with the table;

43. A transmitter as claimed in claim 42, wherein the transmitter is operable to transmit data in accordance with a Digital Video Broadcasting including the Digital Video Broadcasting-Terrestrial, Digital Video Broadcasting-Handheld standard or the Digital Video Broadcasting-Terrestrial2 standard.

44. A receiver for receiving data from Orthogonal Frequency Division Multiplexing (OFDM) modulated signal, the receiver including a data processing apparatus operable to map symbols received from a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol into an output symbol stream, the data processing apparatus comprising:

a de-interleaver operable to read-into a memory the predetermined number of data symbols from the OFDM sub-carrier signals, and to read-out of the memory the data symbols into the output symbol stream to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are de-interleaved from the OFDM sub-carrier signals, and

an address generator operable to generate the set of addresses, the addresses being generated for the received data symbols to indicate the OFDM sub-carrier signal from which the received data symbols are to be mapped into the output symbol stream, the address generator comprising;

a linear feedback shift register including a predetermined number of register stages and being operable to generate a pseudo-random bit sequence in accordance with a generator polynomial,

a permutation circuit operable to receive the content of the shift register stages and to permute the bits present in the register stages in accordance with a permutation order to form an address of one of the OFDM sub-carriers, and

a control unit operable in combination with an address check circuit to re-generate an address when a generated address exceeds a predetermined maximum valid address, wherein

the predetermined maximum valid address is approximately five hundred, and

the linear feedback shift register has eight register stages with a generator polynomial for the linear feedback shift register of R′

_i-1[7]=R′

_i-1[0]⊕

R′

_i-1[1]⊕

R′

_i-1[5]⊕

R′

_i-1[6] and the permutation order forms, with an additional bit, a nine bit address R_i[n] for the i-th data symbol from the bit present in the n-th register stage R′

_i[n] in accordance with the table;

45. The receiver as claimed in claim 44, wherein the receiver is operable to receive data which has been modulated in accordance with a Digital Video Broadcasting standard including the Digital Video Broadcasting-Terrestrial, Digital Video Broadcasting-Handheld or the Digital Video Broadcasting-Terrestrial2 standard.

46. A method of transmitting input data symbols via a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol, the method comprising:

receiving a predetermined number of the input data symbols for mapping onto the predetermined number of sub-carrier signals,

reading-into an interleaver memory the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals,

reading-out of the interleaver memory the data symbols for the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the input data symbols are interleaved on the sub-carrier signals,

generating the set of addresses, the addresses being generated for the input data symbols to indicate the sub-carrier signals onto which the input data symbols are to be mapped, the generating the set of addresses comprising;

using a linear feedback shift register including a predetermined number of register stages to generate a pseudo-random bit sequence in accordance with a generator polynomial,

using a permutation circuit operable to receive the content of the shift register stages to permute the bits present in the register stages in accordance with a permutation code to form an address, and

re-generating an address when a generated address exceeds a predetermined maximum valid address, wherein

the predetermined maximum valid address is approximately five hundred, and

the linear feedback shift register has eight register stages with a generator polynomial for the linear feedback shift register of R′

_i[7]=R′

_i-1[0]⊕

R′

_i-1[1]⊕

R′

_i-1[5]⊕

R′

_i-1[6], and the permutation order forms, with an additional bit, a nine bit address R_i[n] for the i-th data symbol from the bit present in the n-th register stage R′

_i[n] in accordance with the table;

47. The method of transmitting as claimed in claim 46, further comprising transmitting the data symbols via the sub-carrier signals of the OFDM symbols is in accordance with a Digital Video Broadcasting standard including the Digital Video Broadcasting-Terrestrial Digital Video Broadcasting-Handheld, the Digital Video Broadcasting-Terrestrial2 standard or the Digital Video Broadcasting-Cable2 standard.

48. A method of receiving data from Orthogonal Frequency Division Multiplexing OFDM modulated symbols, the method comprising:

receiving a predetermined number of data symbols from a predetermined number of sub-carrier signals from the OFDM symbols for forming an output data stream,

reading-into an interleaver memory the predetermined number of data symbols from the OFDM sub-carrier signals,

reading-out of the interleaver memory the data symbols into the output symbol stream to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are de-interleaved from the OFDM sub-carrier signals, and

generating the set of addresses, the addresses being generated for the received symbols to indicate the OFDM sub-carrier signals from which the received data symbols are to be mapped into the output symbol stream, the generating the set of addresses comprising;

using a linear feedback shift register including a predetermined number of register stages to generate a pseudo-random bit sequence in accordance with generator polynomial,

using a permutation circuit to receive the content of the shift register stages and to permute the bits present in the register stages in accordance with a permutation code to form an address, and

re-generating an address when a generated address exceeds a predetermined maximum valid address, wherein

the predetermined maximum valid address is approximately five hundred, and

the linear feedback shift register has eight register stages with a generator polynomial for the linear feedback shift register of R′

_i[7]=R′

_i-1[0]⊕

R′

_i-1[5]⊕

R′

_i-1[6], and the permutation order forms, with an additional bit, a nine bit address R_i[n] for the i-th data symbol from the bit present in the n-th register stage R′

_i[n] in accordance with the table;

49. The method of receiving as claimed in claim 48, wherein the receiving the data symbols from the sub-carrier signals of the OFDM symbols is in accordance with a Digital Video Broadcasting standard including the Digital Video Broadcasting-Terrestrial, Digital Video Broadcasting-Handheld, the Digital Video Broadcasting-Terrestrial2 standard or the Digital Video Broadcasting-Cable2 standard.