Patent ID: 7782757

Claim:
A method for adaptively allocating pilot signals in a wireless communication system, the method comprising: receiving, by a receiving unit, channel data, including channel length (L) data and coherence time (CT) data, and inter-carrier interference power (P ICI ) data; selecting, by a selecting unit, when L is greater than a first channel length threshold (L TH1 ), a first number of pilot signals between a minimum value of L and a maximum number of pilot signals N P,MAX , wherein the first number of pilot signals N P are equally spaced in time according to the CT data, and equally spaced in frequency; selecting, by the selecting unit, when L is less than L TH1 and P ICI is less than a power threshold (P TH ), a second number of pilot signals such that the second number of pilot signals is between the minimum value of L and N P,MAX , wherein the second number of pilot signals are equally spaced in time according to the CT data, and equally spaced in frequency; and selecting, by the selecting unit, when L is less than L TH1 and P ICI is greater than P TH , a third number of pilot signals such that the third number of pilot signals is equal to n times L (nL), wherein n is an integer, the third number of pilot signals being equally spaced in time according to the CT data, and allocated according to a cluster (n) clustered pilot scheme with a cluster size equal to n, the n-sized clusters being clustered in frequency.