Multi-user time-frequency code diversity mt-cdma equivalent subcarrier allocation system and method

Abstract

The invention discloses an equivalent subcarrier allocation system and method of multi-user multi-tone code division multiple access MT-CDMA. The system and the method comprises the steps of obtaining a gain value of each user on each equivalent subcarrier in an MT-CDMA system according to a channel gain value of each user on each subcarrier; evaluating that how many equivalent subcarriers does each user need to select for transmission according to a user data speed threshold value, wherein the subcarriers in the sub-blocks are ensured to have similar transmission characteristics by use of an evenly-spaced subcarrier block diversity mode; carrying out equivalent subcarrier allocation according to an irrigation principle by taking each subcarrier sub-block as an equivalent subcarrier. The system and the method have the advantages that the characteristic that the speed difference of the users are relatively high is taken into consideration, different speed demands of the multi-user MT-CDMA system can be satisfied, the system and the method are compatible with an existing self-adaptive resource allocation system of multi-user MT-CDMA, and the existing system can be modified conveniently.

Description

technical field [0001] The invention relates to an equivalent subcarrier allocation system and method, in particular to an equivalent subcarrier allocation system and method for multi-user time-frequency code diversity MT-CDMA. Background technique [0002] In the future mobile communication system, users have more and more business demands for high-speed and high-quality data transmission, so how to provide high-quality services for more users on limited radio frequency resources becomes more and more important. Patent ZL201310187393.7 provides a time-frequency code diversity MT-CDMA system. This system can not only use time-frequency code diversity, but also accommodate more users without reducing the data rate of a single user in the system. It is a kind of Promising solution. But in the wireless channel, for the multi-user time-frequency code diversity MT-CDMA system, one or more sub-blocks (equivalent sub-carriers) can be allocated to each user according to the transmi...

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Problems solved by technology

But in the wireless channel, for the multi-user time-frequency code diversity MT-CDMA system, one or more sub-blocks (equivalent sub-carriers) can be allocated to each user according to the transmission rate of each user. If it is only randomly allocated, although it is complicated The degree is lower, but it will lead to some equivalent subcarriers in deep fading that do not have enough power to carry any information bits, and are allocated to users who cannot use them with very high probability, and the fading parameters of different users in the system are Completely independent, the fact is that for the same transmitter, different users experience different fading conditions, and if the equivalent subcarriers used by users are allocated reasonably, their transmission performance will be greatly improved

However, considering that different users have great differences in the source rate requirements, the data rate of different monitoring and monitoring signals ranges from hundreds of bits / s to tens of Kbits / s, the data rate of digital voice signals requires tens of Kbits / s, and the data rate of video signals requires several tens of Kbits / s. The data rate needs to be hundreds of Kbit / s or several Mbit / s or tens of Mbit / s, so for the time-frequency code diversity MT-CDMA system provided by patent ZL201310187393. The allocation algorithm obviously cannot meet the needs of different users for the source rate

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