OFDMA system frequency time 2-D wire-less resource scheduling method

A technology of wireless resource scheduling and system frequency, applied in orthogonal multiplexing systems, electrical components, multiplexing communications, etc. or spectral efficiency, etc.

Inactive Publication Date: 2011-01-26
BEIJING UNIV OF POSTS & TELECOMM
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, these current allocation methods consider resource allocation from the perspective of subcarriers (frequency domain), using the uncorrelation of fading between subcarriers and multi-user diversity, without considering the time domain variation of fading channels. At this time, the system High throughput or spectral efficiency cannot be achieved; if the time-domain change information of the fading channel can also be known at the sending end, it can be used to bring time diversity and corresponding multi-user diversity to further improve spectral efficiency (system capacity)

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  • OFDMA system frequency time 2-D wire-less resource scheduling method
  • OFDMA system frequency time 2-D wire-less resource scheduling method
  • OFDMA system frequency time 2-D wire-less resource scheduling method

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Embodiment Construction

[0075] In order to further understand the present invention, we will perform simulation analysis and verification below:

[0076] In the simulation, WSNR (Worst SNR) is used to represent the worst signal-to-noise ratio in the cell, which is defined as the signal-to-noise ratio (SNR) when the user is at the edge of the cell, and does not consider the effects of shadow fading and fast fading.

[0077] In order to facilitate the comparison between different methods, two scheduling methods, OFDM-TDMA and random allocation, are also simulated in the scheduling of OFDMA frames. The OFDM-TDMA scheduling method is to allocate time slots to different users. The time slot occupies the entire frequency band; and the random resource allocation is to randomly allocate frequency-time blocks to users.

[0078] The resource scheduling performance of a downlink OFDMA cell is simulated in the 5GHz frequency band. The path loss factor is selected as n=4, and the shadow fading standard deviation is 10d...

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Abstract

Analyzing issue of OFDMA system resource scheduling deeply, the invention discloses system model of frequency and time two dimensional dynamic resource scheduling and resource scheduling strategy based on OFDMA frame. The invention also discloses high performance method for scheduling two dimensional dynamic resource of frequency and time in OFDMA system, and converts optimization problem of linear programming to optimization problem of non-linear programming, which is further converted to simple two steps scheduling method so as to reduce scheduling complexity. Taking full advantage of fading characteristic in frequency domain and time domain in OFDM system, using capacity of wireless channel farthest, the invention reaches higher efficiency of frequency spectrum and system capacity.

Description

Technical field [0001] The invention belongs to the field of wireless communication, and particularly relates to a frequency-time two-dimensional wireless resource scheduling method of an OFDMA system. Background technique [0002] OFDM (Orthogonal Frequency Division Multiplexing: Orthogonal Frequency Division Multiplexing) is a special multi-carrier transmission technology that divides a wide transmission bandwidth into multiple orthogonal sub-carriers for parallel transmission of data. Of course, OFDM can also be regarded as a modulation technology or multiplexing technology. One of the biggest advantages of OFDM technology is to combat multipath fading. Since the entire transmission bandwidth is divided into multiple narrow-band sub-carriers, the signal in each sub-carrier can be regarded as flat fading. In a single-carrier modulation system, the fading of the channel will affect the entire signal bandwidth; however, in an OFDM multi-carrier modulation system, only a small p...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04J4/00H04J11/00
Inventor 张兴王文博
Owner BEIJING UNIV OF POSTS & TELECOMM
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