A new ICI mitigation method with generalized data‐allocation for OFDM systems

Abstract

SUMMARYThis paper describes an ICI mitigation method based on the generalized data-allocation of (1, − ) for orthogonal frequency division multiplexing systems. To improve the performance of the ICI mitigation for the higher-frequency offset, we propose an efficient search algorithm to generate the sub-optimal parameter for maximizing the carrier-to-interference ratio (CIR). The CIR and bit error rate performances of the proposed method were derived in this paper. The performances with different carrier frequency offset scenarios were evaluated by computer simulations. According to the simulation results, the performance of the proposed ICI mitigation scheme is better than that of the conventional ICI self-cancellation scheme and is nearly the same as that of the ICI self-cancellation scheme for the optimal parameter . Additionally, the proposed ICI mitigation scheme has a dramatically reduced hardware complexity in comparison with the ICI self-cancellation scheme for the optimal parameter .

A novel ICI self‐cancellation scheme for OFDM systems

“…If there is a frequency offset, the orthogonality between the subcarriers will be distorted and the intercarrier interference (ICI) occurs. One direct way to reduce ICI is self-cancellation [1][2][3][4][5][6][7].…”

“…., N −2, and this is called the constant weighted scheme. In [5], the constant weighted scheme's differentiation part is replaced to reduce its computational complexity. In [6], the conjugate and the phase shift schemes are combined together, and its data allocation is X (l) = X (l), X (l +1) = e j /2 X * (l), l = 0, 2, .…”

“…, N /2−1, In other words, its coefficient pair is (1, −1). This scheme has better CIR than all previous schemes [1][2][3][4][5][6]. To improve further, we propose to modify the symmetric scheme [7] by changing the coefficient pair from (1, −1) to (1, − ) where is between 0 and 1.…”