Decouple-and-forward relaying for dual-hop Alamouti transmissions

In this letter, decouple-and-forward (DCF) relaying for dual-hop Alamouti transmissions is proposed as enhanced amplify-and-forward (AF) relaying to achieve spatial diversity gain especially provided by a two-antenna relay. DCF relaying that consists of decoupling, re-encoding and amplifying needs a little more complicated relay than AF relaying but a less complicated one than decode-and-forward (DF) relaying. Assuming uncorrelated Rayleigh fading channels, we derive a probability density function (PDF) of end-to-end signal-to-noise ratio (SNR) for the DCF system and provide its bit error rate (BER) performance. Numerical investigation shows that the analysis provided in this letter is exact and in dual-hop Alamouti transmissions, DCF achieves BER close to DF and even better BER when SNR is low

Performance analysis of diversity techniques in wireless communication systems: Cooperative systems with CCI and MIMO-OFDM systems

This Dissertation analyzes the performance of ecient digital commu- nication systems, the performance analysis includes the bit error rate (BER) of dier- ent binary and M-ary modulation schemes, and the average channel capacity (ACC) under dierent adaptive transmission protocols, namely, the simultaneous power and rate adaptation protocol (OPRA), the optimal rate with xed power protocol (ORA), the channel inversion with xed rate protocol (CIFR), and the truncated channel in- version with xed transmit power protocol (CTIFR). In this dissertation, BER and ACC performance of interference-limited dual-hop decode-and-forward (DF) relay- ing cooperative systems with co-channel interference (CCI) at both the relay and destination nodes is analyzed in small-scale multipath Nakagami-m fading channels with arbitrary (integer as well as non-integer) values of m. This channel condition is assumed for both the desired signal as well as co-channel interfering signals. In addition, the practical case of unequal average fading powers between the two hops is assumed in the analysis. The analysis assumes an arbitrary number of indepen- dent and non-identically distributed (i.n.i.d.) interfering signals at both relay (R) and destination (D) nodes. Also, the work extended to the case when the receiver employs the maximum ratio combining (MRC) and the equal gain combining (EGC) schemes to exploit the diversity gain