Channel equalization method and wireless communication system based on LRA algorithm

Abstract

The scheme of the invention adopts an LRA algorithm to decompose an equivalent channel matrix after frequency domain equalization and to carry out signal processing on the received data according to decomposition results. As a decision-feedback equalization structure is adopted, the dependence of a transmitter on channel information can be reduced as well as reducing the peak-to-average power ratio of the system effectively; when a receiver takes charge of T transformation, the transmitter can transmit information directly without knowing the channel information; and when the transmitter takes charge of the T transformation, the transmitter needs only know part channel information, namely the transformation matrix T. Moreover, as the LRA algorithm transfers the received data to the space in which the noise resisting ability is enhanced, data decision in the space is more reliable, thus reducing the probability of inaccurate decisions effectively and improving the system performance.

Description

technical field [0001] The invention relates to the technical field of wireless broadband access, in particular to a channel equalization method based on an LRA algorithm and a wireless communication system. Background technique [0002] Channel equalization (Channel Equalization) technology, as an effective anti-multipath fading technology for high-speed wireless communication, will be adopted by the future 4G Long-Term Evolution (LTE) system. During the transmission of the transmitted signal in the wireless channel environment, due to the existence of reflection, diffraction, refraction and other phenomena in the surrounding environment, the transmitted signal reaches the receiving end after different delays, because the amplitude and phase of each delayed signal are different , when superimposed at the receiving end, there will be a drastic change in the signal amplitude. This phenomenon is called multipath fading. When the data transmission rate is high, the maximum del...

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Problems solved by technology

[0008] see Figure 4 As shown, it is a schematic diagram of the 4QAM bit error rate simulation of the current improvement scheme compared with the independent MMSE frequency domain equalization, from Figure 4 It can be known that although the three TH pre-equalization combined with frequency domain equalization schemes are not as good as MMSE frequency domain equalization at low SNR, their performance advantages will gradually be reflected with the increase of SNR, from Figure 4 It can also be seen that when the SNR exceeds 12dB, the performance of MMSE frequency domain equalization gradually lags behind the three frequency domain equalizations combined with TH precoding. It can be seen that the elimination of residual ISI by using TH pre-equalization can bring Significant improvement in performance, and this performance improvement will be further enhanced as the modulation order rises

[0009] see Figure 5 As shown, it is a schematic diagram of the 16QAM target of the current improvement scheme compared with the MMSE frequency domain equalization alone. It can be seen from the figure that under the 16QAM modulation mode, the three frequency domain equalization schemes combined with TH precoding all exceed the optimal MMSE Frequency domain equalization, this is because, under high-order modulation, the deterioration of system performance by residual ISI will become very significant, thus seriously curbing the bit error performance of the system

[0010] According to the above content, it can be known that using TH precoding to eliminate residual ISI can significantly improve performance, but at the same time, the structure based on TH precoding will also increase the peak-to-average ratio to a certain extent, and TH precoding requires the transmitter Know the accurate channel information, which has certain difficulties in the high-speed mobile communication environment

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