ENHANCED PHYSICAL DOWNLINK CONTROL CHANNEL SCRAMBLING AND DEMODULATION REFERENCE SIGNAL SEQUENCE GENERATION

• US 20140355531A1
• Filed: 08/05/2013
• Published: 12/04/2014
• Est. Priority Date: 08/03/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Han, Seunghee, Zhu, Yuan, Chen, Xiaogang, Qin, Yi, Fwu, Jong-Kae
• Granted Patent: US 9,402,251 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04J 11/0036 at the receiver
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 27/20 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/2692 with preamble design, i.e. with negotiation of the synchronisation sequence with transmitter or sequence linked to the algorithm used at the receiver
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Methods, apparatuses, and systems are described to provide enhanced physical downlink control channel scrambling and demodulation reference signal sequence generation.

Claims

1-25. -25. (canceled)

26. An apparatus to be employed in an enhance node B (eNB), the apparatus comprising:

scrambling circuitry to receive a bit sequence that includes downlink control Information (DCI) to be transmitted on an enhanced physical downlink control channel (EPDCCH) and to scramble the bit sequence based on a cell identifier to provide a scrambled bit sequence; and

modulating circuitry coupled with the scrambling circuitry to receive the scrambled bits and to modulate the scrambled bits, with a quadrature phase shift keying modulation scheme, to provide a block of complex-valued modulation symbols.

27. The apparatus of claim 26, wherein a scrambling initialization seed includes the cell identifier, and the scrambling circuitry is to scramble the DCI bits based on the scrambling initialization seed.

28. The apparatus of claim 26, wherein the cell identifier is a virtual cell identifier provided to the scrambling circuitry by a radio resource control layer,

29. The apparatus of claim 28, wherein:

the cell identifier is a virtual cell identifier;

the DCI is to be transmitted in a first EPDCCH set;

the virtual cell identifier corresponds to the first EPDDCH set; and

the scrambling circuitry is to scramble the DCI bits based on a scrambling initialization seed chit given by

c_int=└

n_s/2┘

*2⁹+N_ID^ePDCCH

where n_s is a slot number within a radio frame and N_ID^ePDCCH is the virtual cell identifier.

30. The apparatus of claim 28, further comprising:

a reference signal (RS) generator to generate demodulation reference signals associated with the EPDCCH based on the virtual cell identifier.

31. The apparatus of claim 26, wherein the cell identifier is a physical cell identifier.

32. The apparatus of claim 26, further comprising:

cyclic redundancy check (CRC) generating and masking circuitry to generate a bit sequence that includes DCI and CRC bits and to mask the bit sequence based on a radio network temporary identity (RNTI) of a user equipment that is an intended recipient of the DCI.

33. The apparatus of claim 26, wherein the cell identifier is configured by radio resource control (RRC) signaling.

34. The apparatus of claim 26, wherein the apparatus is a mobile device that includes a touchscreen display and one or more cameras.

35. An apparatus to be employed in a user equipment, the apparatus comprising:

demodulating circuitry to receive complex-valued modulation symbols of an enhanced physical downlink control channel (EPDCCH) set that include downlink control information (DCI) and demodulate the complex-valued modulation symbols to provide a bit sequence; and

descrambling circuitry coupled with the demodulating circuitry to descramble the bit sequence based on a initialization seed parameter that corresponds to the EPDCCH set to provide a descrambled bit sequence.

36. The apparatus of claim 35, wherein the initialization seed parameter is a virtual cell identifier and the descrambling circuit is configured to receive the virtual cell identifier from a radio resource control layer.

37. The apparatus of claim 36, wherein the demodulating circuitry is to receive complex-valued modulation symbols of another EPDCCH set and demodulate the complex-valued modulation symbols to provide another bit sequence;

and

the descrambling circuitry is to descramble the other bit sequence based on an initialization seed parameter that corresponds to the other EPDCCH set to provide another descrambled bit sequence.

38. The apparatus of claim 35, wherein the cell identifier is a physical cell identifier and the user equipment further comprises:

control circuitry to;

receive primary and secondary synchronization signals from an evolved Node B (eNB);

determine the physical cell identifier based on the primary and secondary synchronization signals; and

provide the physical cell identifier to the descrambling circuitry.

39. The apparatus of claim 35, wherein the cell identifier is configured by radio resource control (RRC) signaling.

40. An apparatus to be employed in an enhanced node B (eNB), the apparatus comprising:

a reference signal (RS) generator to generate an RS sequence to be transmitted on a pair of orthogonal cover code (OCC) user equipment reference signal (UE-RS) resource elements (REs); and

scrambling circuitry to use a common scrambling sequence for both REs.

41. The apparatus of claim 40, wherein the RS sequence is r(m) and is given by:

42. The apparatus of claim 40, wherein the RS sequence is r(m), is to be transmitted by 2 antenna ports, and is given by:

43. The apparatus of claim 40, further comprising:

modulating circuitry to map at least part of the reference signal sequence r(m) to complex-valued modulation symbols a_k,l^(p) in a subframe, using normal cyclic prefix according to;

44. The apparatus of claim 40, wherein the common scrambling sequence is based on a virtual cell identifies.

45. The apparatus of claim 44, further comprising:

a radio resource control layer to provide the scrambling circuitry with the virtual cell identifier.

46. An apparatus to be employed in a user equipment, the apparatus comprising:

channel estimation circuitry to

receive a reference signal sequence for a first antenna port on an orthogonal frequency division multiplexing (OFDM) symbol, and

estimate a channel for the first antenna port for the UE based on the received reference signal sequence and an assumption that the reference signal sequence is transmitted to another UE for a second antenna port; and

channel compensation circuitry coupled with the channel estimation circuitry to receive an estimate of the channel and compensate a received signal.

47. The apparatus of claim 46, wherein the channel estimation circuitry is to perform a de-spreading operation on a received signal based on the assumption.

48. The apparatus of claim 47, wherein the de-spreading operation is based on an orthogonal cover code.

49. One or more computer-readable media having instructions that, when executed, cause a user equipment to:

determine a reference signal sequence received for a first antenna port for communications between the UE and an enhanced node Bis also used for communications of a second antenna port; and

perform a blind decoding operation for enhanced physical downlink control channel (EPDCCH) based on said determination.

50. The one or more computer-readable media of claim 49, wherein the instructions, when executed, further cause the user equipment to:

process the reference signal sequence for the first antenna port on an orthogonal frequency division multiplexing (OFDM) symbol; and

estimate a channel for the first antenna port for the UE based on the reference signal sequence and determination that the reference signal sequence is also used for communications of a second antenna port.

51. The one or more computer-readable media of claim 50, wherein the instructions, when executed, further cause the user equipment to:

compensate a received signal based on the estimate of the channel.