Amplitude limiter for predicting parallel branch and amplitude limiting method

Abstract

The predicting parallel branched amplitude limiter and amplitude limiting method is applied in adaptive determining feedback equalizer. The predicting parallel branched amplitude limiter includes n-th power of M amplitude limiters; the first multiplexer and n serially connected delay units. The amplitude limiting method includes the following steps: receiving one signal to be processed and n-th power of M defaultings and performing addition operation to obtain n-th power of M output signals; limiting the amplitudes of the said output signals to output n-th power of M amplitude-limiting signals; and selecting one from the said amplitude-limiting signals for output based on n selecting signals of different delay time.

Description

technical field [0001] The invention relates to a predictive parallel branch slicer (Predicted Parallel Branch Slicer) and a slicer method, especially the predictive parallel branch slicer and slicer method applied in an adaptive decision feedback equalizer. Background technique [0002] In recent years, the International Institute of Electrical and Electronics Engineers (IEEE) has formulated the transmission standard of Gigabit Ethernet. In this transmission standard, four wires in Unshield Twisted Pair-Category 5 (UTP-CAT5) transmission lines are used to transmit gigabit-per-second data. In order to meet such a fast transmission rate, the transmitter receiver (transceiver) of each network node must overcome inter-symbol interference (Inter-Symbol Interference, ISI), echo (Echo), near-end crosstalk (near-end crosstalk) Talk, nEXT) and long-range crosstalk (Far-end Cross Talk, FEXT) and other phenomena caused by noise. [0003] See Figure 1A , which is a functional block ...

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Problems solved by technology

But in this way, the undeservedly increased delay time will make the waveform response seen by the feedback equalizer 22 as shown in the example diagram Figure 2C as shown ( Figure 2C The coordinates of are only used to represent the relative size relationship, so the coordinate axis has no absolute unit), due to the additional n delay units, the subsequent intersymbol interference related to the delay time of the first n units will be limited to zero, such as As indicated by the arrow, the feedback equalizer 22 cannot operate correctly and the overall signal-to-noise ratio of the system will be greatly reduced

Therefore, although the above method can enable the feedback equalizer 22 to perform pipeline operation and increase the processing speed, it will also greatly reduce the overall signal-to-noise ratio of the system and cause the signal quality to degrade, which is not enough to solve the problem caused by the unreasonably increased delay time. problem, the feedforward equalizer 21 in this known technical means must be compensated by corresponding design changes, but this will make the circuit of the feedforward equalizer 21 more complicated, and it still cannot completely solve the problem of signal quality degradation

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