Orthogonal frequency division multiple access (OFDMA) system signal processing method and device

Abstract

The invention discloses an orthogonal frequency division multiple access (OFDMA) system signal processing method and a device to lower signal distortion of an OFDMA system. The OPDMA system signal processing method includes: a base station device sends reference signals to a terminal device and receives the present downlink subchannel quality parameters determined and responded by reference signals sent by the terminal device according to the base station device; targeting to each subcarrier, adjusting error vector magnitude (EVM) repair parameters used by a pre-set EVM repair algorithm corresponding to the subcarrier according to feedback channel quality parameters of each subchannel from the terminal device; based on the adjusted EVM repair parameters of the subcarrier, using the pre-set EVM repair algorithm to conduct the EVM repair to a frequency domain OFDMA signal on the subcarrier. The frequency domain OFDMA signal on the subcarrier is obtained from a signal distorted frequency domain OFDMA signal changing from time domain to frequency domain.

Description

technical field [0001] The invention relates to the OFDMA technical field of a mobile communication system, in particular to a signal processing technology of an OFDMA system. Background technique [0002] Due to the frequency selective response of the wireless channel, the main idea of ​​OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) technology is to divide the given channel into several mutually orthogonal sub-channels in the frequency domain, and each sub-channel uses a The sub-carriers are modulated, and the sub-carrier sequences are transmitted in parallel, so the frequency response of the sub-channels is relatively flat, and the signal bandwidth is smaller than the relevant bandwidth of the channel, which greatly reduces ISI (Inter-Symbol Interference, Inter-Symbol Interference); Due to the orthogonal nature of the carrier spectrum, there will be no mutual interference, which improves the spectrum utilization of the channe...

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Problems solved by technology

[0013] 2. Generally, the linear region of the power amplifier is limited, and it is difficult for the power amplifier to meet the requirements of linear amplification of all OFDMA signals.

[0014] 3. The peak-to-average ratio requires power amplifiers, A / D (analog-to-digital), and D / A (digital-to-analog) converters to have a large linear amplification range, which increases the complexity of the OFDMA system, thereby increasing the base station equipment and terminals. equipment cost

When the channel quality of several mutually orthogonal sub-channels changes, the EVM repair parameters should change with the channel quality, otherwise the EVM repair effect will be relatively poor, resulting in serious signal distortion in the OFDMA system

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