Symbol-Spaced Turbo Frequency Domain Equalization for Precoded Continuous Phase Modulation

Qing YAN  Qiang LI  Sheng LUO  Shaoqian LI 

Publication
IEICE TRANSACTIONS on Communications  Vol.E95-B  No.6  pp.2065-2073
Publication Date: 2012/06/01
Online ISSN: 1745-1345
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
Keyword: 
continuous phase modulation (CPM),  turbo equalization,  precoding,  frequency domain equalization (FDE),  Laurent decomposition, 

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Summary: 
In this paper, a low-complexity symbol-spaced turbo frequency domain equalization (FDE) algorithm based on Laurent decomposition is proposed for precoded binary continuous phase modulation (CPM) with modulation index h=1/2. At the transmitter, a precoder is utilized to eliminate the inherent memory of the CPM signal. At the receiver, a matched filter based on Laurent decomposition is utilized to make the detection symbol-spaced. As a result, the symbol-spaced iteration can be taken between the equalizer and the decoder directly without a CPM demodulator, and we derive a symbol-spaced soft interference cancellation frequency domain equalization (SSIC-FDE) algorithm for binary CPM with h=1/2. A new data block structure for FDE of partial response CPM is also presented. The computational complexity analysis and simulations show that this approach provides a complexity reduction and an impressive performance improvement over previously proposed turbo FDE algorithm for binary CPM with h=1/2 in multi-path fading channels.