Design and analysis of post-coded OFDM systems

This paper discusses the design and analysis of post coded OFDM (PC-OFDM) systems. Coded or precoded OFDM systems are generally employed to overcome the symbol recovery problem in uncoded OFDM systems. We show that PC-OFDM systems are a special case of precoded OFDM systems that offer advantageous complexityperformance trade-offs. In particular, PC-OFDM systems introduce frequency diversity by manipulating the OFDM symbols in the time domain so that the computational complexity of the system can be significantly reduced. We discuss the design principles of PC-OFDM transmitter that uses upsampling operation and the spreading codes to introduce frequency diversity. We obtain the spreading code construction criterion for minimum error performance and give examples of spreading codes for PC-OFDM systems. We also describe the design of low-complexity receiver for PC-OFDM systems. The bit error rate analysis of the receiver leads us to postulate different design criteria. We investigate dif...

• Type: Journal
• Year: 2008
• Where: TWC
• Authors: S. F. A. Shah, Ahmed H. Tewfik
• Keywords: OFDM Systems, PC-OFDM Systems, Systems, TWC 2008