Communication system

• US 10,716,103 B2
• Filed: 01/12/2016
• Issued: 07/14/2020
• Est. Priority Date: 07/25/2011
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Awad, Yassin Aden, Maruta, Yasushi, Sato, Toshifumi
• Primary Examiner(s): Agosta, Stephen M D
• Application Number:
  US14/993,636
• Publication Number:
  US 20160128038A1
• Time in Patent Office: 1,645 Days
• Field of Search: 455450, 455455, 455464, 3703101, 370328
• 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: H04W 16/28 using beam steering
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A communication system is presented in which a base station is provided for communicating with a plurality of mobile communication devices in a cellular communication system. The base station operates one of more communication cells and communicates subframes, with each of the plurality of communication devices within the cell(s), each comprising the communication resources of a control region for communicating a control channel and the communication resources of a data region for communicating a respective data channel. The base station communicates a control channel having a first DMRS sequence in a control region of some subframes and a control channel having a second DMRS sequence in a control region of other subframes. The second control channel may be transmitted in a radio beam focussed spatially in a direction of a communication device. The first control channel may be transmitted omnidirectionally throughout the cell(s).

Claims

1. A mobile communication device which communicates with a communication apparatus, the mobile communication device comprising:

a memory storing instructions; and

one or more processors configured to execute the instructions to;

receive a physical downlink control channel (PDCCH) of a first type;

receive a first demodulation reference signal (DMRS) and a second DMRS;

receive a first PDCCH of a second type and a second PDCCH of the second type, the second type being different from the first type; and

demodulate the first PDCCH of a second type based on the first DMRS and the second PDCCH of the second type based on the second DMRS,

wherein the first DMRS is associated with the first PDCCH of a second type,

wherein the second DMRS is associated with the second PDCCH of the second type,

wherein the first DMRS is received from a first two antenna ports, and

wherein the second DMRS is received from a second two antenna ports.

2. A communication apparatus which communicates with a mobile communication device, the communication apparatus comprising:

a memory storing instructions; and

one or more processors configured to execute the instructions to;

transmit a physical downlink control channel (PDCCH) of a first type;

transmit a first demodulation reference signal (DMRS) and a second DMRS; and

transmit a first PDCCH of a second type and a second PDCCH of the second type, the second type being different from the first type, wherein the first DMRS is associated with the first PDCCH of a second type,

wherein the second DMRS is associated with the second PDCCH of the second type,

wherein the first DMRS is transmitted on a first two antenna ports, and

wherein the second DMRS is transmitted on a second two antenna ports.

3. A communication control method in a mobile communication device which communicates with a communication apparatus, the communication control method comprising:

receiving a physical downlink control channel (PDCCH) of a first type;

receiving a first demodulation reference signal (DMRS) and a second DMRS;

receiving a first PDCCH of a second type and a second PDCCH of the second type, the second type being different from the first type; and

demodulating the first PDCCH of a second type based on the first DMRS and the second PDCCH of the second type based on the second DMRS,

wherein the first DMRS is associated with the first PDCCH of a second type,

wherein the second DMRS is associated with the second PDCCH of the second type,

wherein the first DMRS is received from a first two antenna ports, and

wherein the second DMRS is received from a second two antenna ports.

4. A method according to the claim 3, wherein a first mapping comprises at least one first resource element for the first two antenna ports.

5. A method according to the claim 4, wherein the first mapping is different from a second mapping that comprises at least one second resource element for the second two antenna ports.

6. A method according to the claim 5, wherein the at least one first resource element is next to the at least one second resource element.

7. A method according to the claim 3, wherein a second mapping comprises at least one second resource element for the second two antenna ports.

8. A communication control method in a communication apparatus which communicates with a mobile communication device, the communication control method comprising:

transmitting a physical downlink control channel (PDCCH) of a first type;

transmitting a first demodulation reference signal (DMRS) and a second DMRS; and

transmitting a first PDCCH of a second type and a second PDCCH of the second type, the second type being different from the first type,

wherein the first DMRS is associated with the first PDCCH of a second type,

wherein the second DMRS is associated with the second PDCCH of the second type,

wherein the first DMRS is transmitted on a first two antenna ports, and

wherein the second DMRS is transmitted on a second two antenna ports.

9. A method according to the claim 8, wherein a first mapping comprises at least one first resource element for the first two antenna ports.

10. A method according to the claim 9, wherein the first mapping is different from a second mapping that comprises at least one second resource element for the second two antenna ports.

11. A method according to the claim 10, wherein the at least one first resource element is next to the at least one second resource element.

12. A method according to the claim 8, wherein a second mapping comprises at least one second resource element for the second two antenna ports.