Data transfer method in use for orthogonal frequency division multiplex system

Abstract

The method comprises: in data transmission units with different bandwidths, sending out M numbers of OFDM symbols contain in each data transmission unit. It features two types of OFDM symbols with different cycle prefix lengths, long cycle prefix OFDM symbol and short cycle prefix OFDM symbol; in the data transmission unit with different bandwidths, transmitting same numbers of OFDM symbols with long cycle prefix and same numbers of OFDM symbols with short cycle prefix.

Description

technical field [0001] The present invention relates to the field of broadband wireless communication, in particular to a data transmission method in the technical field of Orthogonal Frequency Division Multiplexing (OFDM). Background technique [0002] OFDM technology has attracted more and more people's attention due to its high spectral efficiency, strong anti-multipath interference capability, and low implementation cost, and has been pushed as the preferred technology for broadband wireless communication. In the existing OFDM system, the data transmission method is very important. For a general OFDM system, a data transmission unit (such as a frame based on the 802.16OFDMA system, a subframe of the LTE OFDM system, etc.) includes multiple OFDM symbols, and each OFDM symbol has a cyclic prefix at the top, which is It is usually a repetition of a segment of data following an OFDM symbol. Using the cyclic prefix, the OFDM system can not only eliminate the inter-symbol in...

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Problems solved by technology

[0007] The defect of this method is: as can be seen from Table 1, each bandwidth corresponds to a cyclic prefix setting, and cyclic prefixes of different bandwidths are incompatible with each other, and this incompatibility increases the complexity of system implementation , but no gain

In addition, it can also be seen from Table 1 that there are 8 types of cyclic prefix lengths in the 6 types of system bandwidth: 4.69, 5.21, 4.95, 4.82, 4.75, 4.73, 4.77 and 4.79us. It is a very realistic way for users with different bandwidths to communicate with each other. This means that each user needs to match 8 different cyclic prefixes when accessing the system, which also increases the time for users to access the system and the difficulty of actual implementation

[0008] The second method, refer to the OFDM system based on the 802.16 standard, but the method mentioned in this system, the cyclic prefix time length of different bandwidths is the same, does not take into account the differences in the selection of different cyclic prefixes for different types of data

[0009] Therefore, in the existing OFDM systems and standards, when setting cyclic prefixes, the compatibility of different bandwidth cyclic prefix times and the differences in the selection of different cyclic prefixes for different types of data are not fully considered, and some only consider a certain aspect, ignoring other aspects

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