Several high-rate space-time codes combining spatial multiplexing with transmit diversity have been proposed in recent years. They are usually optimized for uncoded transmission with maximum likelihood detection at the receiver. In this paper, also suboptimal receiver structures and the combination with channel coding are investigated.

abstract the study aimed at investigating the efficacy of written corrective feedback (cf) in improving iranian efl learners’ grammatical accuracy. it compared the effects of focused and unfocused written cf on the learners’ grammatical accuracy. 75 efl students formed a one control and two experimental groups. the focused feedback group was provided with error correction in tenses. the unfocus...

In this thesis a new modulation method is studied for an uncoded cognitive transmission (secondary user transmission) in presence of a Primary User (PU) for AWGN and time-varying flat-fading channels. Interference symbol of the PU is assumed to be known at the transmitter of the Cognitive User (CU) beforehand. Based on this knowledge and using a symbol by symbol approach, we design a CU modulat...

In this paper impact of Reed Solomon coding over convolutional coding is analyzed for the different modulation techniques. In this paper communication system model employing GMSK, QPSK, and BPSK modulation techniques are implemented assuming the channel to be AWGN in nature. The simulation results obtained shows that GMSK using Reed Solomon encoding and decoding schemes gives improvement in Bit...

We report experimental demonstration of 8-PAM transmission using an 850 nm VCSEL and 100 m of OM4-type MMF. The 8-level driving signal was generated using a 3-bit DAC, the error rates were measured in real time using a conventional error analyzer. Maximum uncoded bit rate was 37.5 Gbps, which corresponds to 35.2 Gbps with 7% FEC overhead.

By exploiting the electromagnetic wave's four-dimensional signal space, we find that for the additive white Gaussian noise channel, the modulation format with best sensitivity to be an 8-level format with 1.76 dB asymptotic gain over BPSK, for uncoded optical transmission with coherent detection. Low-complexity modulators are presented for the format, as well as an interpretation in terms of qu...

19. ABSTRACT (Continue on reverse if necessary and identify by block number) Several block and convolutional coding options are considered which are applicable to the noncoherent detection of FH/MFSK signals in the presence of tone jamming. The tone jamming model used in this report is the worst-cast tone jamming for an uncoded system. Using decoded probability of bit error as a performance cri...

A novel digital modulation scheme is proposed that allows to increase the data rate compared to uncoded modulation when the out-of-band power is fixed. If the data rate remains unchanged, this corresponds to a bandwidth reduction that is achieved by shaping the signal spectrum by the introduction of correlation in the transmitter. This correlation has to be resolved in the receiver by a maximum...

Elaborating on prior work by Minka, we formulate a general computation rule for lossy messages. An important special case (with many applications in communications) is the conversion of “soft-bit” messages to Gaussian messages. By this method, the performance of a Kalman equalizer is improved, both for uncoded and coded transmission.

Upper and lower bounds on the BER performance of the maximum likelihood detection of uncoded transmission in a SC-FDMA setting are derived for a Rayleigh fading channel. Approximated closed-form expressions are derived for the lower bound of the BER performance for high and low SNR regimes. These derivations are validated by simulation.