Browsing by Author "Shakiba-Herfeh, Mahdi"
Now showing 1 - 3 of 3
- Results Per Page
- Sort Options
Item Open Access LDPC code design for fading interference channels(IEEE, 2019-03) Shakiba-Herfeh, Mahdi; Tanc, A. K.; Duman, Tolga M.We focus on the two-user Gaussian interference channel (IC) with fading and study implementation of different encoding/decoding schemes with low-density parity-check (LDPC) codes for both quasi-static and fast fading scenarios. We adopt Han-Kobayashi encoding, derive stability conditions on the degree distributions of LDPC code ensembles, and obtain explicit and practical code designs. In order to estimate the decoding thresholds, a modified form of the extrinsic information transfer chart analysis based on binary erasure channel approximation for the incoming messages from the component LDPC decoders to state nodes is developed. The proposed code design is employed in several examples for both fast and quasi-static fading cases. Comprehensive set of examples demonstrate that the designed codes perform close to the achievable information theoretic limits. Furthermore, multiple antenna transmissions employing the Alamouti scheme for fading ICs are studied, a special receiver structure is developed, and specific codes are explored. Finally, advantages of the designed codes over point-to-point optimal ones are demonstrated via both asymptotic and finite block length simulations.Item Open Access LDPC code design for fast fading interference channels(IEEE, 2018-05) Shakiba-Herfeh, Mahdi; Tanc, A. K.; Duman, Tolga M.We focus on two-user Gaussian interference channels (ICs) with fast fading and study implementation of explicit all public and Han- Kobayashi (HK) coding schemes with low-density parity-check (LDPC) codes. Stability conditions for the coding schemes are derived, and a modified form of the EXIT chart analysis is proposed to estimate the decoding threshold of LDPC code ensembles. The proposed code design is employed in several examples and the obtained rate pairs are compared with the achievable rate region (ARR) boundaries demonstrating that rate pairs very close to the ARR boundaries are attained. Performance of finite block length codes are also studied through simulations of specific codes picked from the optimized LDPC code ensembles in order to verify the analysis.Item Open Access LDPC codes for interference channels in the primary decodes cognitive regime(Institute of Electrical and Electronics Engineers Inc., 2019) Shakiba-Herfeh, Mahdi; Tanç, A. K.; Duman, Tolga M.We investigate cognitive interference channels (CICs), a variant of two-user ICs in which one of the transmitters (called the cognitive transmitter) has non-causal knowledge of the other's (private user's) message. Prompted by the information theoretical results, we design an explicit coding scheme for CIC in the primary decodes cognitive regime. We present a novel joint decoder and design low-density parity-check codes for this set-up. Simulation results demonstrate that the proposed joint decoder and the designed codes outperform the conventional maximum ratio combining type decoder and the point-to-point optimal codes, respectively.