Power Allocation for Channel Estimation and Performance of Mismatched Decoding in Wireless Relay Networks

• Published in: IEEE transactions on vehicular technology Vol. 59; no. 9; pp. 4639 - 4645
• Main Authors: Nguyen, Duy H N, Nguyen, Ha H
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.2010; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Allocations; Applied sciences; Channel estimation; Channels; Coding; Coding, codes; Connection and protection apparatus; Decoding; Detection, estimation, filtering, equalization, prediction; distributed space-time coding (DSTC); diversity order; Electrical engineering. Electrical power engineering; Estimators; Exact sciences and technology; Exact solutions; geometric programming (GP); Information, signal and communications theory; Mathematical analysis; power allocation (PA); Relay; Relay networks; Relays; Signal and communications theory; Signal to noise ratio; Signal, noise; Space time codes; Studies; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Performance evaluation; Space-time codes; Parameter estimation; Relay; Relay network; Error estimation; Wireless telecommunication; Diversity; Programming; Power supply; Power allocation; Mean square error; Learning; diversity order; Coding; Least squares method; Channel estimation; Optimal planning; Estimation error; Estimator; power allocation (PA); Power electronics; Decoding; Mismatching; geometric programming (GP); distributed space-time coding (DSTC); Wireless network; Gain
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2010.2080296

This paper is concerned with power allocation (PA) among the source and the relays of wireless relay networks to minimize the mean-square error (MSE) of the channel estimation when distributed space-time coding (DSTC) is applied. The optimal PA scheme is numerically obtained by means of geometric programming for the least-squares (LS) estimator, and a closed-form near-optimal PA scheme is also suggested. The impact of imperfect channel estimation on the error performance of DSTC is analyzed for both the LS and linear minimum MSE (LMMSE) channel estimators. It is proved that mismatched decoding of DSTC is able to achieve the same diversity order as coherent decoding of DSTC. Furthermore, when the closed-form PA obtained in the training phase is applied to the transmission phase, mismatched decoding is able to achieve a significant coding gain over the equal-PA scheme (which assigns half of the total power to the source and equally shares the other half to all the relays).