Methods and apparatus for descrambling received uplink transmissions
Methods and apparatus for providing a resource element identification system to process received uplink transmissions. In an embodiment, a method is provided that includes receiving soft-demapped symbols that comprises resource elements. The method also includes descrambling the resource elements of the symbols one-by-one using descrambling bits generated by at least one linear feedback shift register (LFSR). After each symbol is descrambled, a state of the at least one LFSR is stored as a stored state. The method also comprises restoring the stored state to the at least one LFSR before a next symbol is descrambled so that generation of the descrambling bits continues from symbol to symbol. The method also comprises forwarding the descrambled symbols to a downstream combining function.
1. A method, comprising:
receiving soft-demapped symbols, wherein each symbol comprises resource elements;
descrambling the resource elements of the symbols one-by-one using descrambling bits generated by at least one linear feedback shift register (LFSR), wherein after each symbol is descrambled, a state of the at least one LFSR is stored as a stored state in a memory;
restoring the stored state retrieved from the memory to the at least one LFSR before descrambling resource elements of a next symbol so that generation of the descrambling bits continues from symbol to symbol; and
forwarding the descrambled symbols to a downstream combining function.
2. The method of claim 1 , wherein the soft-demapped symbols are received from a new radio (NR) uplink transmission.
3. The method of claim 1 , further comprising initializing the at least one LFSR with an initial value before descrambling a first symbol in a sub-frame or a slot.
4. The method of claim 1 , further comprising storing the stored state in an external memory.
5. The method of claim 1 , further comprising receiving category information associated with resource elements of symbols to be descrambled.
6. The method of claim 5 , further comprising modifying the descrambling bits based on selected category information associated with selected resource elements to be descrambled.
7. The method of claim 6 , using the category information to identify descrambled resource elements that contain uplink control information.
8. The method of claim 7 , further comprising:
combining descrambled resource elements that are identified to contain acknowledgement information to produce combined acknowledgement information; and
storing the combined acknowledgement information in a memory.
9. The method of claim 7 , further comprising:
combining descrambled resource elements that are identified to contain first channel state information to produce combined first channel state information; and
storing the combined first channel state information in a memory.
10. The method of claim 7 , further comprising:
combining descrambled resource elements that are identified to contain second channel state information to produce combined second channel state information; and
storing the combined second channel state information in a memory.
11. An apparatus, comprising:
a receiver that receives soft-demapped symbols, wherein each symbol comprises resource elements;
a descrambler that descrambles the resource elements of the symbols one-by-one using descrambling bits generated by at least one linear feedback shift register (LFSR), wherein after each symbol is descrambled, a state of the at least one LFSR is stored as a stored state in a memory, and wherein the descrambler retrieves the stored state from the memory and restores the stored state to the at least one LFSR before a plurality of resource elements of a next symbol is descrambled so that generation of the descrambling bits continues from symbol to symbol; and
an output interface that forwards the descrambled symbols to a downstream combining function.
12. The apparatus of claim 11 , wherein the soft-demapped symbols are received from a new radio (NR) uplink transmission.
13. The apparatus of claim 11 , wherein the descrambler initializes the at least one LFSR with an initial value before descrambling a first symbol in a sub-frame or a slot.
14. The apparatus of claim 11 , wherein the descrambler stores the stored state in an external memory.
15. The apparatus of claim 11 , wherein the descrambler receives category information associated with resource elements of symbols to be descrambled.
16. The apparatus of claim 15 , further comprising a sequence modifier that modifies the descrambling bits based on selected category information associated with selected resource elements to be descrambled.
17. The apparatus of claim 16 , wherein the descrambler uses the category information to identify descrambled resource elements that contain uplink control information.
18. The apparatus of claim 11 , further comprising a combiner that operates to:
combine descrambled resource elements that are identified to contain acknowledgement information to produce combined acknowledgement information; and
store the combined acknowledgement information in a memory.
19. The apparatus of claim 11 , further comprising a combiner that operates to:
combine descrambled resource elements that are identified to contain first channel state information to produce combined first channel state information; and
store the combined first channel state information in a memory.
20. The apparatus of claim 11 , further comprising a combiner that operates to:
combine descrambled resource elements that are identified to contain second channel state information to produce combined second channel state information; and
store the combined second channel state information in a memory.