Scrambling sequence initialization for coordinated multi-point transmissions

1. A method, comprising:

receiving at a user equipment (UE), a virtual cell identifier from a coordinated multi-point (CoMP) serving cell, wherein the virtual cell identifier is different from a serving cell identifier of the CoMP serving cell;

initializing a UE reference signal (UE-RS) sequence generator based at least in part on the virtual cell identifier;

generating a UE-RS sequence with the UE-RS sequence generator, the UE-RS sequence being associated with the virtual cell identifier; and

generating the UE-RS based at least in part on the UE-RS sequence.

2. The method of claim 1 , further comprising

receiving from an other cell in the CoMP transmission network data scrambled with a scrambling sequence, wherein the scrambling sequence is based at least in part on the serving cell identifier.

3. The method of claim 1 , further comprising

receiving data scrambled with a scrambling sequence from at least one of the CoMP serving cell on a first PDSCH and an other cell in the CoMP transmission network on a second PDSCH, wherein the scrambling sequence is based at least in part on the serving cell identifier.

4. The method of claim 1 , further comprising:

receiving at the UE, a codeword index and a transmission slot index from the CoMP serving cell.

5. The method of claim 4 , further comprising:

receiving at the UE, a virtual UE identifier from the CoMP serving cell.

6. The method of claim 4 , wherein the codeword index comprises one of a serving cell codeword index and a virtual codeword index, and the transmission slot index comprises one of a serving cell transmission slot index and a virtual transmission slot index.

7. A communication device, comprising:

a processor; and

a memory comprising processor executable instructions that, when executed by the processor, configure the communication device to:

receive a virtual cell identifier from a coordinated multi-point (CoMP) serving cell, wherein the virtual cell identifier is different from a serving cell identifier of the CoMP serving cell;

initialize a UE reference signal (UE-RS) sequence generator based at least in part on the virtual cell identifier;

generate a UE-RS sequence with the UE-RS sequence generator, the UE-RS sequence being associated with the virtual cell identifier; and

generate the UE-RS based at least in part on the UE-RS sequence.

8. The communication device of claim 7 , wherein the memory further comprises processor executable instructions that, when executed by the processor, configure the processor to receive data from an other cell in the CoMP transmission network, the data being scrambled with a scrambling sequence, wherein the scrambling sequence is based at least in part on the serving cell identifier.

9. The communication device of claim 8 , wherein the memory further comprises processor executable instructions that, when executed by the processor, configure the communication device to receive data scrambled with a scrambling sequence from at least one of the CoMP serving cell on a first PDSCH and an other cell in the CoMP transmission network on a second PDSCH, wherein the scrambling sequence is based at least in part on the serving cell identifier.

10. The communication device of claim 7 , wherein the memory further comprises processor executable instructions that, when executed by the processor, configure the communication device to receive a codeword index and a transmission slot index from the CoMP serving cell.

11. The communication device of claim 10 , wherein the memory further comprises processor executable instructions that, when executed by the processor, configure the communication device to receive a virtual UE identifier from the CoMP serving cell.

12. The communication device of claim 10 , wherein the codeword index comprises one of a serving cell codeword index and a virtual codeword index, and the transmission slot index comprises one of a serving cell transmission slot index and a virtual transmission slot index.

13. A computer program product, embodied on a non-transitory computer-readable storage medium, comprising:

program code for receiving a virtual cell identifier from a coordinated multi-point (CoMP) serving cell on a physical downlink control channel (PDCCH), wherein the virtual cell identifier is different from a serving cell identifier of the CoMP serving cell;

program code for initializing a UE reference signal (UE-RS) sequence generator based at least in part on the virtual cell identifier;

program code for generating a UE-RS sequence with the UE-RS sequence generator, the UE-RS sequence being associated with the virtual cell identifier; and

program code for generating the UE-RS based at least in part on the UE-RS sequence.

14. The computer program product of claim 13 , further comprising:

program code for receiving data scrambled with a scrambling sequence from at least one of the CoMP serving cell on a first physical downlink shared channel (PDSCH) and an other cell in the CoMP transmission network on a second PDSCH, wherein the scrambling sequence is based at least in part on the serving cell identifier.

15. The computer program product of claim 13 , further comprising program code for transmitting the virtual cell identifier to an other cell in the CoMP transmission network.

16. The computer program product of claim 14 , further comprising:

program code for receiving a codeword index and a transmission slot index from the CoMP serving cell.

17. The computer program product of claim 16 , further comprising:

program code for receiving a virtual UE identifier from the CoMP serving cell.

18. The computer program product of claim 16 , wherein the codeword index comprises one of a serving cell codeword index and a virtual codeword index, and the transmission slot index comprises one of a serving cell transmission slot index and a virtual transmission slot index.

19. A communication device, comprising:

means for receiving a virtual cell identifier from a coordinated multi-point (CoMP) serving cell, wherein the virtual cell identifier is different from a serving cell identifier of the CoMP serving cell;

means for initializing a UE reference signal (UE-RS) sequence generator based at least in part on the virtual cell identifier;

means for generating a UE-RS sequence with the UE-RS sequence generator, the UE-RS sequence being associated with the virtual cell identifier; and

means for generating the UE-RS based at least in part on the UE-RS sequence.

20. The communication device of claim 19 , further comprising means for receiving data scrambled with a scrambling sequence from at least one of the CoMP serving cell on a first PDSCH and an other cell in the CoMP transmission network on a second PDSCH, the scrambling sequence being based at least in part on the serving cell identifier.

21. The communication device of claim 19 , further comprising:

means for receiving a codeword index and a transmission slot index from the CoMP serving cell.

22. The communication device of claim 21 , further comprising:

means for receiving a virtual UE identifier from the CoMP serving cell.

23. The communication device of claim 21 , wherein the codeword index comprises one of a serving cell codeword index and a virtual codeword index, and the transmission slot index comprises one of a serving cell transmission slot index and a virtual transmission slot index.

24. The method of claim 1 , further comprising:

receiving at the UE, the serving cell identifier of the CoMP serving cell.

25. The method of claim 24 , further comprising:

initializing a scrambling sequence generator based at least in part on the serving cell identifier;

generating a scrambling sequence with the scrambling sequence generator, the scrambling sequence being associated with the serving cell identifier; and

generating scrambled data based at least in part on the scrambling sequence.

26. The method of claim 24 , further comprising:

initializing the UE-RS sequence generator based at least in part on the serving cell identifier;

generating a second UE-RS sequence with the UE-RS sequence generator, the UE-RS sequence being associated with the serving cell identifier; and

generating a second UE-RS based at least in part on the second UE-RS sequence.

27. The method of claim 1 , wherein the UE-RS is generated with no UE identification.

28. The communication device of claim 7 , wherein the memory further comprises processor executable instructions that, when executed by the processor, configure the communication device to:

receive the serving cell identifier of the CoMP serving cell.

29. The communication device of claim 28 , wherein the memory further comprises processor executable instructions that, when executed by the processor, configure the communication device to:

initialize a scrambling sequence generator based at least in part on the serving cell identifier;

generate a scrambling sequence with the scrambling sequence generator, the scrambling sequence being associated with the serving cell identifier; and

generate scrambled data based at least in part on the scrambling sequence.

30. The communication device of claim 28 , wherein the memory further comprises processor executable instructions that, when executed by the processor, configure the communication device to:

initialize the UE-RS sequence generator based at least in part on the serving cell identifier;

generate a second UE-RS sequence with the UE-RS sequence generator, the second UE-RS sequence being associated with the serving cell identifier; and

generate a second UE-RS based at least in part on the second UE-RS sequence.

31. The communication device of claim 7 , wherein the UE-RS is generated with no UE identification.

32. The computer program product of claim 13 , further comprising:

program code for receiving the serving cell identifier of the CoMP serving cell.

33. The computer program product of claim 32 , further comprising:

program code for initializing a scrambling sequence generator based at least in part on the serving cell identifier;

program code for generating a scrambling sequence with the scrambling sequence generator, the scrambling sequence being associated with the serving cell identifier; and

program code for generating scrambled data based at least in part on the scrambling sequence.

34. The computer program product of claim 32 , further comprising:

program code for initializing the UE-RS sequence generator based at least in part on the serving cell identifier;

program code for generating a second UE-RS sequence with the UE-RS sequence generator, the second UE-RS sequence being associated with the serving cell identifier; and

program code for generating a second UE-RS based at least in part on the second UE-RS sequence.

35. The computer program product of claim 13 , wherein the UE-RS is generated with no UE identification.

36. The communication device of claim 19 , further comprising:

means for receiving the serving cell identifier of the CoMP serving cell.

37. The communication device of claim 36 , further comprising:

means for initializing a scrambling sequence generator based at least in part on the serving cell identifier;

means for generating a scrambling sequence with the scrambling sequence generator, the scrambling sequence being associated with the serving cell identifier; and

means for generating scrambled data based at least in part on the scrambling sequence.

38. The communication device of claim 36 , further comprising:

means for initializing the UE-RS sequence generator based at least in part on the serving cell identifier;

means for generating a second UE-RS sequence with the UE-RS sequence generator, the second UE-RS sequence being associated with the serving cell identifier; and

means for generating a second UE-RS based at least in part on the second UE-RS sequence.

39. The communication device of claim 19 , wherein the UE-RS is generated with no UE identification.