Invention Grant
- Patent Title: Median weighted tracking for spread-spectrum communications
- Patent Title (中): 用于扩频通信的中值加权跟踪
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Application No.: US09765001Application Date: 2001-01-18
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Publication No.: US06983009B2Publication Date: 2006-01-03
- Inventor: Gary R. Lomp
- Applicant: Gary R. Lomp
- Applicant Address: US DE Wilmington
- Assignee: InterDigital Technology Corporation
- Current Assignee: InterDigital Technology Corporation
- Current Assignee Address: US DE Wilmington
- Agency: Volpe and Koenig, P.C.
- Main IPC: H04B15/00
- IPC: H04B15/00 ; H04K1/00 ; H04L27/30

Abstract:
An improvement for a method and system for tracking a spreading code, used in a code division multiple access (CDMA) system. An input signal has spread-spectrum modulation. The spreading code embedded in the spread-spectrum modulation has a plurality of chips. The input signal is sampled, and half-chip offset samples are formed from the sampled input signal. An even set of the half-chip offset samples are grouped into an early set of samples, and an odd set of the half-chip offset samples are grouped into a late set of samples. Each early set of samples is multiplied by the spreading code c(n+1), c(n+2), . . . , c(n+L), to generate a first plurality of products. L is approximately equal to the number of chips of delay between the earliest and latest multipath signals. A first plurality of sums and magnitudes are computed from the first plurality of products. The first plurality of magnitudes are summed to generate an early signal-energy value. Each late set of samples is multiplied by the spreading-code c(n−1), c(n−2), . . . , c(n−L), thereby generating a second plurality of products. A second plurality of sums and magnitudes are computed from the second plurality of products. The second plurality of magnitudes are summed to generate a late signal-energy value. A difference is calculated between the early signal-energy value and the late signal-energy value, thereby producing an error signal.
Public/Granted literature
- US20020051482A1 Median weighted tracking for spread-spectrum communications Public/Granted day:2002-05-02
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