OFDM receiving and dispatching system for high speed mobile environment

An orthogonal frequency division, transceiver system technology, applied in the field of orthogonal frequency division multiplexing modulation devices, can solve problems such as difficulty in guaranteeing

Active Publication Date: 2008-01-30
TSINGHUA UNIV
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Problems solved by technology

However, the equalizer usually requires ideal channel informa...

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  • OFDM receiving and dispatching system for high speed mobile environment
  • OFDM receiving and dispatching system for high speed mobile environment
  • OFDM receiving and dispatching system for high speed mobile environment

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Embodiment Construction

[0059]According to one aspect of the present invention, provide a kind of OFDM modulation device (referring to accompanying drawing 1), comprise two N / 2 point IFFT units, N is the OFDM system subcarrier number, is used to produce two OFDM subsymbols; Serial-to-parallel conversion The device is used to parallelize the serial data stream; two preprocessing units are used to preprocess the parallel data streams mapped to the input ends of the above two IFFT units; the parallel-serial converter is used to convert the above two IFFT The output of the unit is serially concatenated to form a new OFDM symbol and add a zero suffix.

[0060] The present invention also provides a method for preprocessing at the transmitting end (see accompanying drawing 4), said method comprising: L subcarriers are randomly selected from the frequency domain subsymbol X 1 and x 2 Select and set to zero or a known value, and its subcarrier index set is marked as K 1 and K 2 , and satisfy K 1 ∩ K 2 = ...

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Abstract

An orthogonal frequency division multiplexing OFDM transceiver system that is applicable to high speed mobile environment belongs to the technical field of digital communication and is characterized in that at the sending end, the data is segmented and goes through fast reverse fourier transform respectively, and OFDM sub-symbols after transformation are directly cascaded and are attached with a zero protective suffix, thus a relatively big sub-carrier interval is acquired and intercarrier interference caused by Doppler-spread is lessened, but the sensitivity of the system to inter sub-symbol interference. At the receiving end, an interference cancellation receiving device and method that uses sub-carrier given information is designed and the inter sub-symbol interference caused by multipath delay spread is eliminated. The invention causes little or no loss in spectral efficiency of OFDM system, and under the same channel condition, the system of the invention can improve the moving speed supported by traditional methods by about 1.6 times.

Description

technical field [0001] The invention relates to the technical field of digital communication, in particular to an orthogonal frequency division multiplexing (OFDM) modulation device and a receiving method and device for improving the moving speed of a receiver. Background technique [0002] Orthogonal Frequency Division Multiplexing (hereinafter referred to as OFDM), as a high-efficiency broadband multi-carrier transmission technology, has received extensive attention. Adopted in multiple broadband transmission technology standards such as 802.16. However, while obtaining broadband services, people's demand for mobility continues to grow. For example, high-speed mobile applications such as high-speed railways (speed 350 km / h) can also enjoy services such as high-definition television broadcasting and wireless broadband Internet access. Therefore, improving the ability of the OFDM broadband transmission system to resist time-varying multipath channels and improving the movin...

Claims

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Application Information

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IPC IPC(8): H04L27/26
Inventor 陆建华龙毅匡麟玲
Owner TSINGHUA UNIV
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