Transmitter and method of transmitting and receiver and method of receiving

1. A receiver, comprising:

a demodulator configured to detect a received signal, which includes a convolutionally interleaved stream including a sequence of service frames, each service frame including one or more groups of forward-error-correction encoded data cells;

convolutional deinterleaver circuitry including a plurality of delay portions and configured to convolutionally deinterleave the received forward-error-correction encoded data cells;

a forward-error-correction decoder configured to decode the groups of forward-error-correction encoded data cells; and

controller circuitry configured to

detect a service frame, and from the detected service frame, detect first signaling data representing a number of rows of the convolutional deinterleaver corresponding to a number of the plurality of delay portions to use,

detect second signalling data representing a delay portion of the convolutional interleaver into which a first encoded data cell is to be input, and third signaling data representing a counter indicative of an interleaving position of a first data cell of a first complete group of forward-error correction encoded data cells amongst other interleaver data cells, and

set a commutator of the convolutional deinterleaver circuitry according to the second signalling data, and deinterleave a first group of error-correction encoded data cells from the sequence of service frames using the third signalling data.

2. The receiver as claimed in claim 1 , wherein the first and second signalling data define the third signalling data.

3. The receiver as claimed in claim 1 , wherein the counter indicates a position that exceeds an ATSC subframe boundary.

4. The receiver as claimed in claim 1 , wherein the sequence of service frames are ATSC subframes and the counter exceeds an ATSC subframe boundary.

5. The receiver as claimed in claim 1 , wherein the first group of error-correction encoded data cells is encoded data of one Physical Layer Pipe.

6. The receiver as claimed in claim 1 , wherein the receiver is further configured, when initially acquiring the received signal, not to deinterleave encoded data cells of a group of forward-error-correction encoded data cells from the convolutional deinterleaver circuitry representing a group of forward-error-correction encoded data cells of a Physical Layer Pipe prior to the first complete group of forward-error-correction encoded data cells of a current ATSC subframe that has encoded data cells in a previous ATSC subframe.

7. The receiver as claimed in claim 1 , wherein each of the delay portions includes one or more memory elements, and the controller circuitry is further configured to set an initial content of the one or more memory elements of before inputting the symbols of the received signal with values known to the receiver.

8. The receiver as claimed in claim 7 , wherein the values known to the receiver are dummy values.

9. The receiver as claimed in claim 1 , wherein the values known to the receiver are an algorithmically calculatable sequence of values.

10. The receiver as claimed in claim 1 , wherein the one or more groups of forward-error-correction data cells are in the form of one or more pluralities of constellation-mapped cells.

11. The receiver as claimed in claim 1 , wherein the second signaling data is an ATSC L1-Detail field for a physical layer pipe.

12. The receiver as claimed in claim 1 , wherein the first signalling data is an ATSC L1-Detail CTI_Start_Row field for a physical layer pipe.

13. A television comprising the receiver as claimed in claim 1 .

14. A method, comprising:

detecting a received signal, which includes a convolutionally interleaved stream including a sequence of service frames, each service frame including one or more groups of forward-error-correction encoded data cells;

convolutionally deinterleaving by circuitry including a plurality of delay portions the received forward-error-correction encoded data cells;

forward-error-correction decoding the groups of forward-error-correction encoded data cells;

detecting a service frame, and from the detected service frame, detecting first signaling data representing a number of rows of the convolutional deinterleaver corresponding to a number of the plurality of delay portions to use;

detecting second signalling data representing a delay portion of the convolutional interleaves into which a first encoded data cell is to be input, and third signaling data representing a counter indicative of an interleaving position of a first data cell of a first complete group of forward-error correction encoded data cells amongst other interleaver data cells; and

setting a commutator of the convolutional deinterleaver circuitry according to the second signalling data, and deinterleaving a first group of error-correction encoded data cells from the sequence of service frames using the third signalling data.

15. The method as claimed in claim 14 , further comprising deinterleaving a plurality and groups of error correction encoded data cells, demapping the data cells, and forming television pictures from the received signal.

16. The method as claimed in claim 14 , wherein the one or more groups of forward error-correction encoded data cells are in the form of one or more pluralities of constellation-mapped cells.

17. The method as claimed in claim 14 , wherein the detected service frame is an ASTC subframe.

18. The methods as claimed in claim 14 , wherein the counter indicates a position that exceeds an ATSC subframe boundary.

19. A non-transitory computer readable medium including computer program instructions, which when executed by a computer, causes the computer to perform the method of claim 14 .