Iterative EM Based LDPC CDMA Receiver under Time Varying Interference

1 — The authors of this paper proposed an iterative expectation-maximization (EM) channel estimation based on a low-density parity-check (LDPC) code-division multiple access receiver in their previous work. The receiver algorithm could efficiently estimate both channel coefficients and noise power spectral density (PSD). However, their previous work considered only a single user channel environment, so they tested only for a constant noise PSD. In the current paper, we extend the single user to a more realistic multiuser environment for the testing of a time-varying interference plus noise PSD estimation. Also our proposed adaptive PSD estimation scheme will be compared with a conventional system in which a constant PSD is assumed. It will show that the proposed iterative EM scheme can provide accurate interference plus noise PSD estimates to the LDPC decoder.

• Type: Conference
• Year: 2007
• Where: VTC
• Authors: Don J. Torrieri, Avinash Mathur, Amitav Mukherjee, Hyuck M. Kwon
• Keywords: Interference Plus Noise, Noise Psd, PSD Estimation, VTC 2007