发明名称 |
APPARATUS AND METHODS FOR IMPLEMENTING A SPLIT EQUALIZER FILTER FOR SPARSE CHANNELS |
摘要 |
<p>The invention concerns methods and apparatus for performing channel equalization in a direct-sequence spread spectrum communications system. The methods and apparatus of the present invention are particularly applicable in situations where communication occurs over a channel experiencing multipath interference associated with paths having significantly different lengths. The impulse response - delay profile of such a channel is typically sparse, that is, dominated by a relatively few and widely spaced taps or clusters of closely spaced taps. In one aspect, equalization filter coefficients are calculated based on a channel estimate derived from a single cluster of closely-spaced channel taps collectively having the greatest percentage of energy as indicated by the impulse response - delay profile. In another aspect, equalization filter coefficients are calculated for each of two clusters of closely-spaced channel taps, where the two clusters of closely-spaced channel taps are separated by a delay spread indicative of a sparse channel. In a further aspect where channel equalization coefficients are calculated for each of two clusters of closely-spaced channel taps, the equalization coefficients are jointly optimized during the calculation process.</p> |
申请公布号 |
WO2007085938(A2) |
申请公布日期 |
2007.08.02 |
申请号 |
WO2007IB00158 |
申请日期 |
2007.01.24 |
申请人 |
NOKIA CORPORATION;NOKIA, INC.;ZHANG, JIANZHONG;HEIKKILA, MARKKU, J. |
发明人 |
ZHANG, JIANZHONG;HEIKKILA, MARKKU, J. |
分类号 |
H04B1/707 |
主分类号 |
H04B1/707 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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