Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method and apparatus for multipath delay estimation in direct sequence spread spectrum communication systems

A technique for channel coefficient and estimation, applied in transmission systems, communications between multiple stations, electrical components, etc.

Inactive Publication Date: 2001-03-21
TELEFON AB LM ERICSSON (PUBL)
View PDF0 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] The invention solves the problem of multipath delay estimation when a direct sequence spread spectrum (DS-SS) signal is transmitted in a multipath fading channel

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method and apparatus for multipath delay estimation in direct sequence spread spectrum communication systems
  • Method and apparatus for multipath delay estimation in direct sequence spread spectrum communication systems
  • Method and apparatus for multipath delay estimation in direct sequence spread spectrum communication systems

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0029] The present invention will now be described in connection with a pilot channel-based system such as IS-95 downlink. The pilot channel for such a system is unmodulated. However, the present invention can also be applied to other systems, such as systems using modulated pilot channels, pilot symbols, or no pilot signals at all. The invention is also described in the text of delayed tracking. It can be seen that the present invention can also be applied to initial delay estimation, in which there is no previously estimated delay to be updated.

[0030] A DS-SS communication system adopting the present invention is shown in image 3 in. The DS-SS transmitter 303 transmits the DS-SS signal through the radio channel 304, which is received by the receiver composed of the RF part 301 and the baseband processor 402. The RF part amplifies, filters, and down-mixes this signal to baseband frequency, typically OH E This signal is also typically sampled and quantized to generate data sam...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

Multipath delay estimation of a direct sequence spread spectrum (DS-SS) signal transmitted in a multipath fading channel is accomplished by measuring the envelope of the signal to determine a new delay estimate. Delay estimates are also obtained in ray strength order, by subtracting out the influence of the stronger rays on the weaker ones. This subtraction approach can be performed iteratively, allowing further refinement of the delay estimates. Delay estimates can also be determined by minimizing the mean square error (MSE) between a measured correlation function and a modeled correlation function. The minimum mean square error (MMSE) approach can performed iteratively, to further refine the delay estimates. Maximum likelihood (ML) delay estimates can also be obtained by exploiting side information regarding the transmit and receive pulse shapes.

Description

Invention field [0001] The present invention relates to a method and equipment for estimating the transmission delay of a multipath radio signal, and more particularly to a method and equipment for estimating the delay of a multipath signal in a telecommunication system using direct sequence spread spectrum technology. equipment Background of the invention [0002] Because more of the radio spectrum is commercially available, and cellular phones have become commonplace, the field of radio communications is expanding at an extraordinary rate. In addition, there is currently an evolution from analog communication to digital communication. In digital communication, speech is expressed by a series of bits that are modulated and sent from the base station to the phone. The phone demodulates the received waveform to recover these bits, which are then converted back to speech. There is also a growing need for data services, such as e-mail and Internet access, which r...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H04B1/711H04B1/709H04B1/7113H04B7/26
CPCH04B1/7113H04B1/711H04B1/709
Inventor E·索洛尔G·波托姆利R·拉梅斯S·陈纳克舒
Owner TELEFON AB LM ERICSSON (PUBL)
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com