1. A reassigning system for reassigning a plurality of tracking units of a wireless receiver for receiving a plurality of multipath signals in a predetermined time period to reconstruct correspondingly an original signal, the reassigning system comprising: a searcher for searching a plurality of peaks in a multipath signal with a first predetermined resolution, and accordingly acquiring a plurality of corresponding searching time positions; a tracker comprising the plurality of tracking units, each of the tracking units tracking a corresponding peak with a predetermined tracking time position and a second predetermined resolution wherein the second predetermined resolution is higher than the first predetermined resolution; and an assigning management unit comprising: a matching module for matching the plurality of searching time positions and the plurality of predetermined tracking time positions by a predetermined matching process, and accordingly generating a plurality of combinations of matching pairs; an estimating module for estimating the searching time position and the predetermined tracking time position in each combination of matching pairs by a predetermined estimating process, and accordingly generating an assigning value corresponding to the combination; an assigning table for storing relationships of the plurality of searching time positions and the plurality of predetermined tracking time positions of the plural combinations of matching pairs, and storing the assigning value of the combination; and an assigning module for acquiring from the assigning table a smallest assigning value among the plural assigning values and a combination of matching pairs corresponding to the smallest assigning value; wherein the assigning management unit reassigns the plurality of tracking units to track the plurality of path signals according to the relationship of the searching time positions and the predetermined tracking time positions in the acquired combination of matching pairs from the assigning module.