OPTIMIZED SIGNALING OF DEMODULATION REFERENCE SIGNAL PATTERNS

• US 20150207605A1
• Filed: 04/01/2015
• Published: 07/23/2015
• Est. Priority Date: 06/28/2010
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Jngren, George, Sorrentino, Stefano
• Granted Patent: US 9,584,280 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 72/0466 the resource being a scrambling code
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

Orthogonality in cyclic shift (CS) and orthogonal cover code (OCC) selection for DMRS in MIMO is improved by new n_DMRS to n_DMRS⁽²⁾ mapping patterns. Values in the mapping tables are arranged in sets, with minimum CS separation between the values in each set. Additionally, the semi-static n_DMRS is independently configurable for each UL component carrier (CC) in the case of cross-CC scheduling in carrier aggregation, and the PHICH allocation formula that defines the allocation of the PHICH process relative to the k^th codeword (CW) on the c^th UL CC is a function of both the CS index n_DMRS,k,c⁽²⁾ that is dynamically assigned to a certain layer of the considered CW and the semi-static CS offset n_DMRS,c⁽¹⁾ for the c^th CC.

Claims

1. A method of determining Cyclic Shift (CS) and Orthogonal Cover Code (OCC) values associated with DeModulation Reference Signals (DMRS), for each transmission layer, by a transceiver in a wireless communication system employing Multiple Input Multiple Output (MIMO) operation, comprising:

receiving a semi-static CS value n_DMRS⁽¹⁾;

receiving a dynamic CS index value n_DMRS;

indexing a predetermined table with n_DMRS to obtain a first CS value n_DMRS⁽²⁾ and an OCC value n_DMRS^OCC associated with DMRS for layer 0;

deriving a first CS value associated with DMRS for each other layer by adding a different integer multiple of a predetermined minimum offset to n_DMRS⁽²⁾; and

calculating a second CS value for each layer by adding n_DMRS⁽¹⁾ to the first CS value;

wherein within the predetermined table, the CS values n_DMRS⁽²⁾ are arranged in two or more sets of CS values n_DMRS⁽²⁾, the CS values n_DMRS⁽²⁾ within each set being separated by the predetermined minimum offset.

2. The method of claim 1 wherein the dynamic CS value n_DMRS comprises three bits.

3. The method of claim 1 further comprising deriving an OCC value associated with DMRS for other layers by adding a predetermined OCC offset to the OCC value n_DMRS^OCC associated with DMRS for layer 0.

4. The method of claim 3 further comprising encoding DMRS for all layers using the second CS value for each layer and the final OCC value for each layer.

5. The method of claim 1 wherein the predetermined minimum offset is three.

6. The method of claim 1 wherein receiving a dynamic CS value n_DMRS comprises receiving n_DMRS in a Downlink Control Information (DCI) format.

7. The method of claim 1 wherein receiving from a transmitter a semi-static CS value n_DMRS⁽¹⁾ comprises receiving n_DMRS⁽¹⁾ via higher layer signaling.

8. The method of claim 1 wherein the predetermined table comprises:

9. The method of claim 1 wherein the predetermined table comprises:

10. The method of claim 1 wherein the predetermined table comprises:

11. The method of claim 1 wherein the predetermined table comprises twelve mapping entries.

12. The method of claim 11 wherein the predetermined table the CS values n_DMRS⁽²⁾ are arranged in two sets.

13. A method of determining Cyclic Shift (CS) and Orthogonal Cover Code (OCC) values associated with DeModulation Reference Signals (DMRS) for each transmission layer and component carrier, and Physical Channel (PHICH) allocation, by a receiver in a wireless communication system employing Multiple Input Multiple Output (MIMO) operation and carrier aggregation, comprising:

receiving a semi-static CS value n_DMRS,c⁽¹⁾ associated with each component carrier (CC) in the case of cross-CC scheduling; and

wherein the allocation of the PHICH process relative to the k^th codeword on the c^th CC is a function of both a first CS value n_DMRS,k,c⁽²⁾ associated with DMRS for a certain layer of a codeword and the semi-static CS value n_DMRS,c⁽¹⁾ associated with the c^th CC.

14. The method of claim 13 wherein a PHICH allocation rule comprises:

n_PHICH,k,c^group=(I<sub>PRB—

RA</sub><sup>lowest—

index</sup>+n_DMRS,k,c⁽²⁾+n_DMRS,c⁽¹⁾)mod N_PHICH^group+I_PHICHN_PHICH^group

n_PHICH,k,c^seq=(└

I<sub>PRB—

RA</sub><sup>lowest—

index</sup>/N_PHICH^group┘

+n_DMRS,k,c⁽²⁾+n_DMRS,c⁽¹⁾)mod 2N_SF^PHICH

where the parameters I<sub>PRB—

RA</sub><sup>lowest—

index</sup>, N_PHICH^group, I_PHICH and N_SF^PHICH have the meaning defined in 3GPP TS 36.212 V.9.0.0.

15. The method of claim 13 wherein a PHICH allocation rule comprises:

n_PHICH,k,c^group=(I<sub>PRB—

RA</sub><sup>lowest—

index</sup>+n_DMRS,k,c⁽²⁾+n_DMRS,c⁽¹⁾)mod N_PHICH^group+I_PHICHN_PHICH^group

n_PHICH,k,c^seq=(└

I<sub>PRB—

RA</sub><sup>lowest—

index</sup>/N_PHICH^group┘

+n_DMRS,k,c⁽²⁾)mod 2N_SF^PHICH

where the parameters I<sub>PRB—

RA</sub><sup>lowest—

index</sup>, N_PHICH^group, I_PHICH and N_SF^PHICH have the meaning defined in 3GPP TS 36.212 V.9.0.0.

16. The method of claim 13 wherein a PHICH allocation rule comprises:

n_PHICH,k,c^group=(I<sub>PRB—

RA</sub><sup>lowest—

index</sup>+n_DMRS,k,c⁽²⁾)mod N_PHICH^group+I_PHICHN_PHICH^group

n_PHICH,k,c^seq=(└

I<sub>PRB—

RA</sub><sup>lowest—

index</sup>/N_PHICH^group┘

+n_DMRS,k,c⁽²⁾°

n_DMRS,c⁽¹⁾)mod 2N_SF^PHICH

where the parameters I<sub>PRB—

RA</sub><sup>lowest—

index</sup>, N_PHICH^group, I_PHICH and N_SF^PHICH and have the meaning defined in 3GPP TS 36.212 V.9.0.0.