Emitting and receiving method of up-link system in space-time block code MC-CDMA

Abstract

This invention relates to an emitting and receiving method for up-link in the MC-CDMA system including the following steps: emission: data flows of each user are divided into two paths by 2x2 orthogonal empty packet coding, the data flows of each are duplicated to form P paths of parallel data flows to be spread with frequency domain, the emitted symbol period is the integer multiple of the chip period, carrying out quick Fourier transformation to be added and emitted, receiving: carrying quick Fourier transformation to signals received by antennas, de-spreading, matching and filtering signals of each sub-carrier of each user then to carry out empty time decode and time domain merging then frequency domain merging to the merged signals and then space domain merging to get the decisive variable of the user signals and then demodulating BPSK to resume data signals of the user.

Description

technical field [0001] The invention belongs to mobile communication multiple-input multiple-output (MIMO) space-time block code technology, multi-carrier (MC) technology and code division multiple access (CDMA) [0002] technology field. Background technique [0003] In 3G, CDMA is the most important technology, and multi-carrier modulation will be the key technology of future broadband wireless transmission system. Combining multi-carrier technology with CDMA technology to form a multi-carrier CDMA system is one of the important directions for future mobile communication development. The combination of multi-carrier technology and CDMA technology has three main forms: multi-carrier CDMA (MC-CDMA), multi-carrier direct-sequence spread spectrum CDMA (multicarrier DS-CDMA) and multi-tone modulation CDMA (MT-CDMA) [R. Prasad, S. Hara. An Overview of Multi-carrier CDMA. IEEE Commun. Magazine, 1997, 35(12): 126-133]. Among them, the MC-CDMA scheme is considered to be the most...

AI Technical Summary

Problems solved by technology

Since the STBC-MC-CDMA scheme is constructed based on the traditional MC-CDMA scheme, each subcarrier is required to experience a frequency non-selective fading channel. To ensure this condition, the chip period of the spreading sequence and the symbol period of the transmission must be Subject to certain restrictions, obviously this is not conducive to the realization of high-speed wireless data transmission

In this STBC-MC-CDMA scheme, in order to ensure that each subcarrier experiences frequency non-selective fading, the space-time coded symbols must go through a 1:Q serial-to-parallel (S / P) conversion link, which increases the symbol period by Q times, but This also increases the number of subcarriers of the system by Q times, which will occupy more valuable frequency resources. At the same time, because the number of subcarriers has increased by Q times, it also greatly increases the complexity of the transceiver itself and the complexity of processing, and The performance of the system has not been improved because of this, and in practice, since the channel is dynamically changing, it is necessary to dynamically adjust Q to adapt to the change of the channel, which will be very difficult to implement in practice

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