Method, apparatus and system for estimating channels

• US 8,483,619 B2
• Filed: 04/24/2012
• Issued: 07/09/2013
• Est. Priority Date: 11/12/2008
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Wan, Lei, Cheng, Xingqing, Zhou, Mingyu, Zhao, Yajun
• Primary Examiner(s): Ferguson, Keith
• Application Number:
  US13/454,804
• Publication Number:
  US 20120208577A1
• Time in Patent Office: 441 Days
• Field of Search: 455/515, 455/507, 455/500, 455/517, 455/434, 455/550.1, 455/552.1, 455/553.1, 455/445, 455/455, 455/450, 455/509, 455/454, 455/67.11, 455/403, 455/422.1, 455/426.1, 455/426.2, 370/310, 370/328, 370/329, 370/330, 370/338, 370/343, 370/345, 370/431, 370/436, 370/442
• US Class Current: 455/67.11
• CPC Class Codes: H04J 11/0023 Interference mitigation or co-ordination direct sequence spread spectrum [DSSS] systems H04B1/7097; frequency hopping H04B1/713; allocation criteria for ingress interference avoidance H04L5/0062; frequency allocation criteria for requirements on out-of-channel emissions H04L5/0066; arrangements for removing intersymbol interference or baseband equalisers H04L25/03006; peak power aspects in multicarrier modulation H04L27/2614; power management H04W52/00; traffic scheduling H04W72/54, H04W72/541
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource
• CPC Class Codes: H04W 72/29 between an access point and the access point controlling device

Abstract

A method, an apparatus and a system for estimating channels are disclosed. A method for estimating channels includes: receiving, by a User Equipment (UE), downlink signals sent by two or more Access Points (APs), wherein no common reference signal is comprised in any data channel symbol domain except a preset symbol domain in the downlink signals; and performing, by the UE, channel estimation according to the downlink signals. The technical solution disclosed herein eliminates the interference between the reference signal and the data signal, enables the UE to estimate the channel value between the UE and the cooperative APs accurately, and improves the UE performance.

Claims

1. A channel estimation method, comprising:

receiving, by a User Equipment (UE), a downlink signal sent by a first Access Point (AP), wherein a first common reference signal is sent by the first AP in a preset symbol domain in the downlink signal, and data signals from the first AP are excluded from being sent in a specific time-frequency lattice of the preset symbol domain designated for utilization by a second AP for sending a second common reference signal;

receiving, by the UE, the second common reference signal; and

performing, by the UE, channel estimation according to the first common reference signal and the second common reference signal.

2. The method of claim 1, wherein the preset symbol domain is configured to be occupied by a control channel.

3. The method of claim 1, wherein the downlink signal includes a control channel symbol domain and a data channel symbol domain, and if the control channel symbol domain is smaller than the preset symbol domain, the preset symbol domain includes data channel symbols.

4. A channel estimation apparatus, comprising:

a receiver, configured to;

receive a first downlink signal sent by a first Access Point (AP), including a first common reference signal sent in a preset symbol domain in the first downlink signal; and

receive a second downlink signal sent by a second AP, including a second common reference signal sent in a preset symbol domain in the second downlink signal; and

an estimating unit, configured to perform channel estimation according to the first common reference signal and the second common reference signal, wherein the estimating unit further comprises;

a first estimating unit, configured to regard a data signal in each of the first downlink signal and the second downlink signal as an interference signal against the channel estimation;

a second estimating unit, configured to estimate the interference signal; and

a third estimating unit, configured to eliminate the interference signal from each of the first downlink signal and the second downlink signal according to a result of estimating the interference signal.

5. A channel estimation apparatus, comprising:

a receiver, configured to;

receive a downlink signal sent by a first Access Point (AP), wherein a first common reference signal is sent by the first AP in a preset symbol domain in the downlink signal, and data signals are excluded from being sent in a specific time-frequency lattice of the preset symbol domain in the downlink signal, the specific time-frequency lattice of the preset symbol domain being designated for utilization by a second AP for sending a second common reference signal;

receive the second common reference signal; and

an estimating unit, configured to perform channel estimation according to the first common reference signal and the second common reference signal.

6. The channel estimation apparatus of claim 5, wherein the downlink signal includes a control channel symbol domain and a data channel symbol domain, and if the control channel symbol domain is smaller than the preset symbol domain, the preset symbol domain includes data channel symbols.