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Method of orthogonal FDM for modulatng sub-carrier separation and sub-band cross arrangement

An orthogonal frequency division and cross-arrangement technology, applied in the field of digital information transmission, can solve the problem of increasing the burden of information transmission and achieve the effect of reducing the amount of system feedback information

Inactive Publication Date: 2009-07-08
SHANGHAI JIAOTONG UNIV
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  • Abstract
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Problems solved by technology

The burden of information transmission will further increase

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  • Method of orthogonal FDM for modulatng sub-carrier separation and sub-band cross arrangement

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Embodiment Construction

[0014] In order to better understand the technical solution of the present invention, the following will be further described in conjunction with the accompanying drawings:

[0015] The present invention carries out following steps at originating:

[0016] (1) Arranging the effective data subcarriers of the OFDM system in sequence;

[0017] Divide the above subcarriers equally into 4 consecutive subbands;

[0018] (2) Of the 4 subbands, 2 are allocated to voice users, and 2 are allocated to data and video users;

[0019] (3) The four sub-bands are arranged crosswise, and the arrangement mode can include two types: voice, data and video, voice, data and video (such as figure 1 shown) and data and video, voice, data and video, voice;

[0020] (4) After Turbo product encoding and QAM modulation, the general voice user information is mapped to the voice subband, and the data and video user information is modulated and mapped according to the instruction mode of adaptive subcarr...

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Abstract

The invention relates to a method for sub-carrier division and sub-band cross arrangement of orthogonal frequency division multiplexing modulation, which is used in the technical field of digital information transmission. The present invention utilizes the characteristics of periodic fading of frequency selective channels to divide OFDM subcarriers into two types of sub-bands arranged crosswise, and distribute them to two types of users. One type of users adopts adaptive allocation technology, and the other One type of user adopts OFDM modulation transmission technology, and the two types of sub-bands are arranged alternately to occupy all effective data sub-carriers, and the data of the two types of users are mapped to their corresponding sub-carriers at the transmitter. The method reduces the amount of system feedback information required for adaptive subcarrier allocation, and at the same time takes into account the needs of general voice users.

Description

technical field [0001] The invention relates to the technical field of digital information transmission, in particular to a method for sub-carrier division and cross-arrangement of sub-bands in Orthogonal Frequency Division Multiplexing Modulation (OFDM). Background technique [0002] In the IEEE802.16 protocol, the subcarrier group assigned to the user is composed of subcarriers separated by a certain distance, the purpose is to prevent all subcarriers assigned to the same user from being in deep fading at the same time, and to ensure the minimum quality requirements of the user's transmission information , but for users who need a large amount of data or video transmission, the quality cannot be guaranteed. [0003] In multipath channel transmission, the channel presents the characteristics of frequency selective fading, the bit error rate performance of each subcarrier in the OFDM symbol is determined by the channel impulse response in the frequency domain, bit errors mai...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26H04J11/00
Inventor 甘小莺张海滨徐友云宋文涛刘波
Owner SHANGHAI JIAOTONG UNIV
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