Area and power efficient architectures of time deinterleaver for receivers
View Patent ↗A method and apparatus for de-interleaving interleaved data in a deinterleaver memory in an Orthogonal Frequency Division Multiplexing (OFDM) based Integrated Services Digital Broadcasting Terrestrial (ISDB-T) receiver. In different embodiments, the apparatus comprises of a OFDM symbol counter along with a divider or a buffer pointer RAM with circular pointer logic, a first lookup table to obtain delay buffer size and interleaving lengths for a given OFDM transmission layer, and a second lookup table to obtain buffer base address and interleaving lengths for a given OFDM transmission layer.
1. An apparatus for de-interleaving interleaved data in an Orthogonal Frequency Division Multiplexing (OFDM) based receiver, said apparatus comprising:
a deinterleaver memory;
an OFDM symbol counter incrementing once for each orthogonal frequency division multiplexing-OFDM symbol, wherein a bit width of said OFDM symbol counter is in the range of 23 to 33 bits;
a divider for calculating intra buffer offset in said deinterleaver memory for every increment of said OFDM symbol counter;
a first lookup table in said deinterleaver memory for obtaining delay buffer sizes for various carriers and interleaving lengths for a given OFDM transmission layer; and
a second lookup table in said deinterleaver memory for obtaining buffer base addresses for various carriers and interleaving lengths for a given OFDM transmission layer, wherein said bit width of said OFDM symbol counter is selected based on uninterrupted television viewing time on a particular channel.
2. The apparatus of claim 1 , wherein said divider comprises a combinational divider.
3. The apparatus of claim 1 , wherein said divider comprises a sequential divider.
4. The apparatus of claim 1 , wherein said first and second lookup tables are stored in a read-only memory (ROM).
5. The apparatus of claim 1 , wherein said first and second lookup tables are implemented using dynamic arithmetic calculations.
6. The apparatus of claim 1 , wherein said delay buffer sizes and said buffer base addresses are obtained from the first and second lookup tables for corresponding carriers and interleaving lengths for a given OFDM transmission layer.
7. The apparatus of claim 1 , wherein said receiver comprises a mobile application receiver.
8. The apparatus of claim 1 , wherein said receiver comprises a mobile television receiver.
9. The apparatus of claim 1 , wherein said receiver comprises an Integrated Services Digital Broadcasting Terrestrial (ISDB-T) receiver.
10. A method of deinterleaving interleaved data in a deinterleaver memory in an Orthogonal Frequency Division Multiplexing (OFDM) based receiver comprising a OFDM symbol counter, a divider, a first lookup table to obtain delay buffer size and interleaving lengths for a given OFDM transmission layer, and a second lookup table to obtain buffer base address and interleaving lengths for a given OFDM transmission layer, said method comprising:
counting received OFDM symbols by incrementing said OFDM symbol counter, wherein said OFDM symbol counter comprises a bit width in the range of 23 to 33 bits;
retrieving a delay buffer size value for a corresponding carrier from said first lookup table;
calculating intra buffer offset by dividing said OFDM symbol counter with said delay buffer size of corresponding carrier;
retrieving a buffer base address for corresponding carrier from said second lookup table;
combining said intra buffer offset and said buffer base address to calculate a memory address to store corresponding carrier data bits; and
storing said carrier data bits at said calculated memory address.
11. The method of claim 10 , further comprising implementing the first and second lookup tables as a read-only memory (ROM).
12. The method of claim 10 , further comprising implementing the first and second lookup tables as dynamic arithmetic calculations.
13. The method of claim 10 , wherein said receiver comprises a mobile application receiver.
14. The method of claim 10 , wherein said receiver comprises a mobile television receiver.
15. The method of claim 10 , wherein said receiver comprises an Integrated Services Digital Broadcasting Terrestrial (ISDB-T) receiver.
16. An Orthogonal Frequency Division Multiplexing (OFDM) based receiver that de-interleaves interleaved data, said receiver comprising:
a deinterleaver memory;
an OFDM symbol counter incrementing once for each orthogonal frequency division multiplexing-OFDM symbol, wherein a bit width of said OFDM symbol counter is in the range of 23 to 33 bits;
a divider for calculating intra buffer offset in said deinterleaver memory for every increment of said OFDM symbol counter;
a first lookup table in said deinterleaver memory for obtaining delay buffer sizes for various carriers and interleaving lengths for a given OFDM transmission layer; and
a second lookup table in said deinterleaver memory for obtaining buffer base addresses for various carriers and interleaving lengths for a given OFDM transmission layer, wherein said bit width of said OFDM symbol counter is selected based on uninterrupted television viewing time on a particular channel.
17. The receiver of claim 16 , wherein said divider comprises any of a combinational divider and a sequential divider.
18. The receiver of claim 16 , further comprising a read-only memory (ROM) that stores said first and second lookup tables.
19. The receiver of claim 16 , wherein said first and second lookup tables are implemented using dynamic arithmetic calculations.
20. The receiver of claim 16 , wherein said delay buffer sizes and said buffer base addresses are obtained from the first and second lookup tables for corresponding carriers and interleaving lengths for a given OFDM transmission layer.