Mean Square Error of Blind Channel Estimation Using a Constant Modulus Algorithm

Zachaeus K. Adeyemo; Ayobami O. Fawole; Robert O. Abolade

Channel Estimation (CE) in multicarrier system especially in Orthogonal Frequency Division Multiplexing (OFDM) systems has become an important technique in wireless communication to reduce the overall effect of high data rate and increase links performance. In wireless channel, which has frequency selective distribution, the transmitted signals are corrupted and resulted in high error at the receiver. However, the existing techniques in use such as Least Square Estimation (LSE), Minimum Mean Square Error (MMSE) are based on single carrier system with pilot symbols for channel estimation to reduce the error. Therefore, in this paper, investigation of the performance of blind channel estimation in sixteen (16) subcarriers OFDM system using a Constant Modulus Algorithm (CMA) is carried out. The system model for sixteen subcarriers OFDM incorporating CMA is developed over the frequency selective fading channel. OFDM system consists of the following signal processing techniques; sixteen channel demultiplexer, Inverse Fast Fourier transform (IFFT), Cyclic Prefix (CP), sixteen channels multiplexer and the Radio Frequency (RF) transmit antenna all at the transmitter. Also, at the receiver are RF receive antenna, sixteen channel demultiplexer, Fast Fourier transform (FFT), sixteen channel multiplexer, Cyclic Prefix (CP) removal and decoder. The input data are generated randomly, converted to bits and divided among the subcarriers to reduce overlapping of bits. The signal processing techniques at both the transmitter and receiver process the signal. The system model is simulated by MATLAB application package and evaluated using Mean Square Error (MSE). This is now compared with the LSE and MMSE estimation. The results obtained using 16-subcarrier OFDM with CMA give lower MSE than with LSE over frequency selective environment.

Select Volume / Issues:

• Volume 7,Issue 3, May 2016

Year:

2016

Type of Publication:

Article

Keywords:

OFDM; Subcarriers; IFFT; Pilots; Blind Channel

Journal:

IJECCE

Volume:

7

Number:

3

Pages:

156-161

Month:

May

ISSN:

2249-071X