Features of equalization in LTE technology with MIMO and SC-FDMA

Abstract

The Long Term Evolution (LTE) is one of communication standards for next-generation mobile phones, which has evolved the high-speed data communication standard HSDPA for the mainstream 3G (third generation) mobile phone system W-CDMA at present. Data communication volume of mobile phones is rapidly increasing at present due to dissemination of smart phones and mobile communication. Therefore, expansion of communication band (capacity) is a critical issue for communication carriers. Because the LTE that allows high-speed data communication with low delay is superior in terms of the radio wave use efficiency, many of major communication carriers in the world have indicated a policy of adopting the LTE. The rapid dissemination of the LTE in the future is expected. In this report we overview the fundamental techniques of equalization in LTE technology with MIMO and SC-FDMA in channels where the maximum delay exceeds the length of the Guard Interval. The goal of employing narrow band subcarriers is to obtain a channel that is roughly constant over each given sub band, which makes equalization much simpler at the receiver. There are considering advantage and disadvantage three types equalization techniques: time domain, frequency domain and turbo equalization. On base of these compeering are giving practical recommendation for choice method of equalization. To enhance this frequency use efficiency, antenna technologies, including Multi Input Multi Output (MIMO) that allows transmission/reception with multiple antennas and Space Division Multiple Access (SDMA) that allows multiple access between base stations, have been introduced. Furthermore, Orthogonal Frequency Division Multiple Access (OFDMA) and Single Carrier Frequency Division Multiple Access (SC-FDMA) are used as multiplexing systems.