Adaptive beamforming apparatus and method

• US 6,937,189 B2
• Filed: 02/12/2003
• Issued: 08/30/2005
• Est. Priority Date: 04/30/2002
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Sang-Choon
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Mull, Fred H.
• Application Number:
  US10/364,398
• Publication Number:
  US 20030201936A1
• Time in Patent Office: 930 Days
• Field of Search: 342/372, 342/374, 342/377, 342/378, 367119-125
• US Class Current: 342/372
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming

Abstract

Disclosed are an adaptive beamforming apparatus and method that despreads an input signal, and determines whether a symbol of despread signal belongs to a pilot sub-channel or non-pilot sub-channel of the despread signal. One of two beamforming algorithms is accordingly enabled. If the symbol belongs to the pilot sub-channel, a first algorithm is used to calculate a weight vector, and if the symbol belongs to the non-pilot sub-channel, a second algorithm is used to calculate the weight vector. A current weight vector is updated using newly calculated weight vector, and a beam pattern is formed based on the updated weight vector.

Claims

1. An adaptive beamforming apparatus, comprising:

a weight vector calculation module configured to select a beamforming algorithm according to a type of sub-channel of a pilot control channel to which a received symbol data belongs, and calculate a weight vector using the selected beamforming algorithm; and

a beamformer configured to generate a beam pattern according to the weight vector calculated at the weight vector calculation module,

wherein the type of sub-channel comprises a pilot sub-channel and a non-pilot sub-channel,

wherein the selected beamforming algorithm is an LMS (Least Means Square) algorithm when the symbol data is of the pilot sub-channel and is a CMA (Constant Modulus Algorithm) when the symbol data is of the non-pilot sub-channel and

wherein if the beamforming algorithm is converted from a first beamforming algorithm to a second beamforming algorithm a last weight vector calculated by the first beamforming algorithm is used as an initial weight vector of the second beamforming algorithm.

2. The apparatus of claim 1, further comprising a despreader to despread an input signal and output the symbol data.

3. The apparatus of claim 1, wherein the LMS beamforming algorithm is a non-blind beamforming algorithm and the CMA beamforming algorithm is a blind beamforming algorithm.

4. The apparatus of claim 1, wherein the sub-channel is a dedicated physical control channel (DPCCH) for transferring control information.

5. An adaptive beamforming method, comprising:

selecting an LMS (least means square) beamforming algorithm if a sub-channel of a pilot control channel to which an input symbol data belongs is a pilot sub-channel and selecting a CMA (Constant Modulus Algorithm) if the sub-channel is a non-pilot sub-channel;

updating a weight vector using the selected beamforming algorithm; and

forming a beam pattern using the updated weight vector,

wherein updating the weight vector comprises using a last weight vector calculated by a first beamforming algorithm as an initial weight vector of a second beamforming algorithm when the beamforming algorithm transitions from the first beamforming algorithm to the second beamforming algorithm.

6. The method of claim 5, wherein the CMA is a blind beamforming algorithm, and wherein the LMS is a non-blind beamforming algorithm.

7. The method of claim 5, wherein the sub-channel is a dedicated physical control channel (DPCCH) for transferring control information.

8. An adaptive beamforming method, comprising:

determining whether a symbol data belongs to a pilot sub-channel or a non-pilot sub-channel of a pilot control channel;

selecting a CMA (Constant Modulus Algorithm) if it is determined the symbol data belongs to the non-pilot sub-channel and selecting an LMS (Least Means Square) algorithm if it is determined the symbol data belongs to the pilot sub-channel;

updating a weight vector using the selected algorithm; and

forming a beam pattern using the updated weight vector,

wherein updating the weight vector comprises using a last weight vector calculated by a first beamforming algorithm as an initial weight vector of a second beamforming algorithm when the beamforming algorithm transitions from the first beamforming algorithm to the second beamforming algorithm.

9. The method of claim 8, wherein the sub-channel is a dedicated physical control channel (DPCCH) for transferring control information.