Method and system for estimating modulation index and frequency offset

A modulation index, frequency offset technology, used in FM carrier systems, baseband system components, shaping networks in transmitters/receivers, etc.

Active Publication Date: 2016-08-03
SPREADTRUM COMM (SHANGHAI) CO LTD
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AI Technical Summary

Problems solved by technology

Since the modulation index specified in the protocol is not unique, the demodulation method based on Viterbi or other related demodulation methods need to estimate the modulation index and frequency offset, and there is no ideal way in the prior art to Simultaneous estimation of modulation index and frequency offset

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  • Method and system for estimating modulation index and frequency offset
  • Method and system for estimating modulation index and frequency offset
  • Method and system for estimating modulation index and frequency offset

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Embodiment Construction

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0038] It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0039] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

[0040] refer to figure 1 , a method for estimating a modulation index and a frequency offset, applied to a blue...

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Abstract

The invention relates to the technical field of electronic communication, and particularly relates to a method for estimating a modulation index and frequency offset. The method is applied to a Bluetooth wireless receiving system and comprises the steps of S1, establishing an operation relation among a differential phase delta theta<ndiff> between adjacent code elements of received signals, a modulation index h of the received signals, a code element symbol sequence I<n-1>, In, I<n+1>, I<n+2> of four successive local reference signals, and a modulation index h0 of the local reference signals, S2, establishing a relation expression provided with a differential phase with frequency offset compensation, wherein the relation expression is as follows: delta theta<n>=delta phi+delta theta<ndiff>, delta theta<n> is the differential phase with frequency offset compensation, and delta phi is frequency offset of the received signals, and S3, estimating the frequency offset and the modulation index of the received signals according to a minimum mean square error criterion. The method provided by the invention realizes simultaneous estimation for the modulation index and the frequency offset through establishing the relation between the modulation index and the differential phase, and is suitable for signal estimation of the Bluetooth basic data rate and frequency offset and modulation index estimation of other GFSK (Gaussian Frequency Shift Keying) signals.

Description

technical field [0001] The invention relates to the technical field of electronic communication, in particular to a method for estimating modulation index and frequency offset. Background technique [0002] Bluetooth (Bluetooth) technology establishes a general short-range wireless interface for the communication environment between fixed equipment or mobile equipment, and further combines communication technology and computer technology, so that various equipment can be connected without wires or cables. Communicate or operate with each other within close range. [0003] The modulation method used in Bluetooth communication is Gaussian Frequency Shift Keying (Gaussian Frequency Shift Keying, GFSK), that is, the binary data stream waveform is smoothed by a Gaussian filter, and then frequency modulated, where the symbol bandwidth product BT is equal to 0.5, and the modulation index is 0.28~ 0.35. Since the modulation index specified in the protocol is not unique, the demodu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L25/02H04L25/03H04L27/10
Inventor 陈希
Owner SPREADTRUM COMM (SHANGHAI) CO LTD
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