A newborn, beyond 3g system named Dynamic Parameter Controlled Orthogonal Frequency and Time Division Multiple Access (DPC/OF-TDMA) is being developed in Japan. In this system, a decision-directed channel estimation (DDCE) technique can be employed for increased channel estimation accuracy in a fast fading environment. This technique however, has structurally unavoidable processing delay due to the decision for the generation of new reference data. In the fast fading environment, propagation characteristics vary during this delay, resulting in channel estimation error or considerable output delay. This paper proposes a novel DDCE method to reduce such estimation error. The proposed channel estimation method is performed by introducing the circuits that are independent of the process of system output. These independent circuits enable to avoid the considerable output delay. In addition, this paper proposes a method of detecting inaccurate channel estimate obtained for errors of decoded data to increase channel estimation accuracy.