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Channel estimation for systems with transmission diversity

A technology of diversity channel and channel estimation, which is applied in the novel field of transmission diversity pilot processing, can solve problems such as no longer effective, insufficient communication performance level, demodulation performance degradation, etc., to reduce transmission power, improve demodulation performance, Effect of Accurate Channel Estimation

Inactive Publication Date: 2010-03-03
QUALCOMM INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when channel conditioning changes more rapidly, such as when a mobile station is operating at high speeds, this assumption is no longer valid and demodulation performance is degraded to the point of being insufficient for the desired level of communication performance

Method used

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  • Channel estimation for systems with transmission diversity
  • Channel estimation for systems with transmission diversity
  • Channel estimation for systems with transmission diversity

Examples

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Embodiment Construction

[0019] figure 1 is a schematic diagram of a wireless communication system 100 that can be designed to support one or more CDMA standards and / or designs (eg, W-CDMA standard, IS-95 standard, cdma2000 standard, HDR specification). For simplicity, the illustrated system 100 includes three base stations 104 in communication with two mobile stations 106 . A base station and its coverage area are often collectively referred to as a "cell". In the IS-95 system, a cell will consist of one or more sectors. In the W-CDMA specification, each sector of the base station and the coverage area of ​​the sector is called a cell. As used herein, the term "base station" is used interchangeably with the terms "access point" or "Node B." The term "mobile station" is used interchangeably with the terms "user equipment (UE)," "subscriber unit," "subscriber station," "access terminal," "remote terminal," or other corresponding terms known in the art. The term "mobile station" includes fixed wirel...

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Abstract

Techniques are disclosed for channel estimation in rapidly changing environments. In one aspect, a difference estimate (630) is updated when a current received symbol comprises a difference between the primary and diversity channels (614), and a sum estimate (620) is updated when a current received symbol comprises a sum of the primary and diversity channels (612). The primary channel and the diversity channel are estimated from the sum estimate and the difference estimate (640). This has the benefit of incorporating the most recently received symbol, resulting in more accurate channel estimates and hence improved demodulation performance, increased system capacity, and lower required transmit power.

Description

technical field [0001] The present invention relates generally to communications, and more particularly to novel and improved methods and apparatus for transmit diversity pilot processing. Background technique [0002] Wireless communication systems are widely employed to provide various types of communications such as voice and data. These systems may be based on Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), or some other modulation technique. CDMA systems offer certain advantages over other types of systems, such as increased system capacity. [0003] A CDMA system can be designed to support one or more CDMA standards, such as (1) "TIA / EIA-95-BMobile Station-Base Station Compatibility Standard for Dual-Mode WidebandSpread Spectrum Cellular System" (IS-95 standard), (2 ) Standards provided by an association named "3rd Generation Partnership Project" (3GPP), contained in a set of documents, including document numbers 3G TS 25.211, 3G TS25.212,...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L25/02H04L1/06
CPCH04L25/0206H04L1/0618H04L25/0228H04L25/0204
Inventor 许大山
Owner QUALCOMM INC