Thanh Hai Vo

Analog single-carrier transmission with frequency-domain equalization

In this paper, a new analog signal transmission technique called analog single-carrier transmission with frequency-domain equalization (analog SC-FDE) is proposed. The proposed analog SC-FDE applies discrete Fourier transform (DFT), frequency-domain spectrum shaping and mapping, inverse DFT (IDFT), and cyclic prefix insertion before transmission. At the receiver, one-tap frequency-domain equalization (FDE) is applied to take advantage of the channel frequency-selectivity. As an example, in this paper, the analog voice transmission is considered. By computer simulation, we evaluate the normalized mean square error (NMSE) performance to show that analog SC-FDE achieves better NMSE performance than conventional analog signal transmission scheme.

Spectrum Efficient Single-Sideband Single-Carrier with Frequency-Domain Equalization

In this paper, a novel spectrum efficient single-sideband single-carrier (SC) with frequency-domain equalization (SSB-FDE) using amplitude shift keying (ASK) modulation (ASK SSB-FDE) is proposed. Similar to the conventional SC transmission with FDE (SC-FDE), the ASK modulated symbol block to be transmitted is transformed by discrete Fourier transform (DFT) into frequency-domain signal. Then, inverse DFT (IDFT) is applied to the upper (or lower) sideband spectrum to obtain the time-domain SSB signal block. The cyclic prefix (CP) inserted SSB signal block is transmitted over a frequency-selective fading channel. At a receiver, the minimum mean square error (MMSE) based FDE is applied. ASK SSB-FDE has lower peak-to-average power ratio (PAPR) and better throughput performance than QAM SC-FDE when the throughput is plotted as a function of peak transmit SNR. This is confirmed by computer simulation assuming a frequency-selective Rayleigh fading channel.

A Novel Analog Signal Transmission using Joint Space- Time Transmit Diversity and Receive Antenna Diversity

Recently, we proposed a novel analog signal transmission technique called analog single-carrier transmission with frequency-domain equalization (analog SC-FDE) and showed that analog SC-FDE achieves better normalized mean square error (NMSE) performance than conventional analog signal transmission. In order to achieve further performance improvement, transmit/receive antenna diversity technique is effective. In digital wireless communications, joint space-time transmit diversity (STTD) and receive antenna diversity is well known as a promising antenna diversity technique which achieves a high diversity order (equal to the product of the number of transmit antennas and the number of receive antennas) with a simple signal processing. In this paper, analog SC- FDE using joint STTD and receive antenna diversity is proposed. A theoretical analysis of the NMSE performance is derived to evaluate the transmission performance of the proposed scheme and is confirmed by computer simulation. We show that joint STTD and receive antenna diversity can significantly improve the NMSE performance of our proposed analog SC-FDE.

Analog SC-FDE using single sideband technique

In order to improve performance of analog signal transmission, we recently proposed a novel analog single-carrier transmission with frequency-domain equalization (analog SC-FDE). Analog SC-FDE adopts double sideband (DSB) technique (referred to as analog SC-DSB-FDE) to transmit signal. In this paper, in order to double the spectrum efficiency of analog SC-DSB-FDE, single sideband (SSB) technique is introduced. Analog SC-SSB-FDE applies discrete Fourier transform (DFT), frequency-domain spectrum shaping filter and mapping, inverse DFT (IDFT), and cyclic prefix (CP) insertion before transmission. At the receiver, one-tap FDE is applied to take advantage of frequency diversity and a spectrum copy for restoring spectrum is applied. By computer simulation, we show that analog SC-SSB-FDE achieves better normalized mean square error (NMSE) performance than conventional analog SSB transmission and keeps the performance quality similar to analog SC-DSB-FDE.

Subcarrier Combining for an Analog Single-Carrier Transmission

Analog single-carrier transmission with frequency-domain equalization (called analog SC-FDE) was recently proposed in order to improve performance of analog signal transmission. Analog SC-FDE signal spectrum has a complex conjugate relation between lower sideband (LSB) and upper sideband (USB) since analog signal is real-valued. Exploiting this property, the received LSB and USB subcarriers can be combined to obtain an additional frequency diversity gain. In this paper, a subcarrier combining method is proposed to improve the performance of analog SC-FDE. A theoretical analysis of normalized mean square error (NMSE) performance is presented to evaluate the effect of subcarrier combining and is confirmed by computer simulation. It is shown that subcarrier combining improves effectively the NMSE performance in multipath fading channel.