基于抽取濾波器多相分解的盲自適應(yīng)符號(hào)同步算法
Blind Adaptive Symbol Synchronization Algorithm Based on Decimation Filters Polyphase Decomposition
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摘要: 針對(duì)軟件無(wú)線電系統(tǒng)中接收信號(hào)采樣時(shí)鐘獨(dú)立于發(fā)送信號(hào)時(shí)鐘的特點(diǎn)，提出了在抽取操作過(guò)程中實(shí)現(xiàn)符號(hào)同步，避免了在基帶階段進(jìn)行內(nèi)插操作，以得到多相位信息的做法．利用過(guò)抽樣信號(hào)固有的多相位信息，通過(guò)最大似然相位誤差撿測(cè)算法，調(diào)整延時(shí)機(jī)構(gòu)，使信號(hào)傳輸延時(shí)匹配于延時(shí)分枝索引值，實(shí)現(xiàn)后續(xù)信號(hào)抽取輸出為最佳采樣值．利用級(jí)聯(lián)積分梳狀(CIC)濾波器和半帶濾波器(HBF)作為抽取濾波器，應(yīng)用濾波器多相分解算法，降低了系統(tǒng)實(shí)現(xiàn)的復(fù)雜性和運(yùn)算量．仿真結(jié)果表明，當(dāng)信號(hào)傳輸延時(shí)匹配于延時(shí)分枝索引值時(shí)，相位誤差和延時(shí)分枝索引值將趨于穩(wěn)定．
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關(guān)鍵詞:
- 軟件無(wú)線電;抽取濾波器;符號(hào)同步;多相分解
Abstract: For the received signals were sampled at a fixed rate that is asynchronous with the data clock in software radio, we implement symbol synchronization during the process of decimation which replace general methods by using an interpolator in the baseband stage, and Maximum Likelihood(ML) timing synchronization techniques can be incorporated into the filters polyphase decomposition in a natural way. In order to match the timing delay of received signals to the data timing delay, the timing delay structure was adjusted by utilizing the timing error. Cascaded Integrator Comb (CIC) filters and HalfBand Filters (HDF) served as decimation filters that reduce the system complexity and computational burden to a certain extent. The numerical simulation results show that the value of timing delay structure will be converged to a constant with small fluctuation when the received signals timing delay matches the data timing delay, and the output from the last stage of FIR is the optimal sampled signals. -
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