| 摘要 |
An apparatus and method for improving error rate performance in a communication channel utilizes a dual decision feedback equalizer (DDFE) through the application of selective attenuation. An improved DDFE comprises first and second decision feedback equalizers (DFEs) operably connected in parallel to receive a series of input signals zk. The DFEs independently generate two series of decisions &acirc ;1k and &acirc ;2k in relation to peak magnitudes of the series of transmitted signals zk by filtering the series of decisions &acirc ;1k and &acirc ;2k to generate filtered outputs (a*p)1k and (a*p)2k based on previous decisions, and summing the filtered outputs (a*p)1k and (a*p)2k with the transmitted input series zk to generate two series of decision variables ã1k and ã2k, to remove effects of intersymbol interference. The improved DDFE further comprises first and second attenuation blocks, so that when a mismatch is detected between the series of decisions &acirc ;1k and &acirc ;2k, a selective attenuation gain less than one is introduced into each feedback filter loop. This results in a reallocation of some of the decision energy associated with the correct series of decisions to the erroneous series and helps the erroneous DFE to make correct decisions sooner, thereby improving the error rate performance of the channel.
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