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Digital push-pull impedance-modulating (RM) pre-emphasis driver overcomes the power overhead of equalization in voltage-mode (VM) drivers, improving the output stage efficiency ~2-3x. A compact, fully-digital RAM-DAC implementation with pattern lookup compensates both duty-cycle distortion and driver nonlinearity, while providing a programmable pre-emphasis. A testchip fabricated in 90nm CMOS process...
Multimedia applications like high definition digital television push the manufacturers to increase available bandwidth mainly in Powerline Communication (PLC) links. Because of this needs in this work a PLC link control is developed to maximize the information rate meanwhile the bit error rate (BER) is maintained under a desired reference limit. The developed control system has a unique variable called...
This paper presents some results on MMSE turbo equalization applied to real sea water trials in the Atlantic ocean. High order modulations (8-PSK, 16-QAM and 32-QAM) have been tested. The channel data rate on the underwater acoustic channel is up to 20 kbps. The receiver includes timing recovery, equalization, interleaving and channel coding. The results which are evaluated in term of bit error rate...
This letter presents a soft decision feedback equalizer (SDFE), for multilevel modulation. In contrast to common turbo principle which only uses the extrinsic information from the decoder, the SDFE can be used in the channel equalizer for calculation of the a posteriori probability (APP) by collecting information of the entire block as in maximum a-posteriori probability (MAP) algorithm. Replaced...
We consider a time division duplex multiple-input multiple-output (nt × nr MIMO). Using channel state information (CSI) at the transmitter, singular value decomposition (SVD) of the channel matrix is performed. This transforms the MIMO channel into parallel subchannels, but has a low overall diversity order. Hence, we propose X-Codes which achieve a higher diversity order by pairing the subchannels,...
In this paper, we propose a generalized multiple-input multiple-output (MIMO) transmit preprocessing system, where both the channel coding and the linear MIMO transmit precoding components exploit the knowledge of the channel. Moreover, we also propose a novel technique, hereby referred to as pilot symbol assisted rateless (PSAR) coding, where a predetermined fraction of binary pilot symbols is interspersed...
This paper proposes an iterative receiver employing multiuser detection (MUD) and channel estimation for uplink MIMO-OFDM interleave-division multiple access (IDMA). IDMA can perform low-complexity MUD by employing a low-rate channel code and an individual interleaver for each user, and is expected to improve spectrum efficiency in mobile communications. However, an excellent channel estimator has...
The amplify-and-forward (AF) and the decode-and-forward (DF) cooperative coded diversity is compared with the conventional receiver coded diversity in terms of the bit error rate (BER). The comparison assumes channel coding with non-binary modulations, and fast fading channels with path-loss attenuation proportional to the distance between nodes. Numerical results obtained by extensive computer simulations...
Single Carrier Frequency Division Multiplex (SC-FDMA) is the modulation technique being considered in Long Term Evolution (LTE) proposal announced recently. The reason for this stems from the fact that SC-FDMA envelope fluctuation is considerable lower than that of conventional Orthogonal Frequency Division Multiplex (OFDM) technique, thereby results in less sensitivity to the nonlinear distortion...
Iterative decoding is an efficient technique to overcome the disadvantage of Bit-Interleaved Coded Modulation (BICM) over AWGN channels. In order to reduce the unnecessary iterations of the iterative decoding process, stopping criteria technique has been introduced. Since the iterative process of Bit-Interleaved Coded Modulation with Iterative Decoding (BICM-ID) is proceeded between the demapper and...
This paper assesses the spectral efficiencies that can be achieved in theory and simulation for several channel models, and where the same spectral efficiencies can result from different combinations of the signal constellation and channel code rate. A trade-off analysis is presented both for satellite and terrestrial channels for the impact on the spectral efficiency G of increasing the modulation...
A digital baseband receiver ASIC that supports GSM/GPRS/EDGE and Evolved EDGE is implemented in 0.13 ??m CMOS technology. The design centers around two main blocks: an adaptive channel equalizer processes GMSK/8PSK/16QAM and 32 QAM modulated signals and a flexible channel decoder supports convolutional and turbo codes, as required for Evolved EDGE. The receiver occupies 2.0 mm2 and the average power...
This paper presents simulation model for DVB-T system following the ETSI standard EN 300 744. Simulation model includes DVB-T transmitter and receiver, supports different system parameters and transmission channels. The model provides overall evaluation of DVB-T system parameters and can be used for educational and testing purposes.
Cooperative diversity techniques make a reduction in spectral efficiency despite of an increase in reliability. In this paper we propose a novel relaying protocol in a cooperative network with decode and forward (DF) relays to improve the spectral efficiency in addition to achieving full diversity order (maximum available reliability). The proposed protocol keeps the transmission rate fixed to the...
This paper presents a design of a turbo decoder for advanced terrestrial DMB(AT-DMB) baseband receiver SoC. The turbo decoder uses the max-log-map algorithm with simple min function. It features an interleaver address generator that computes the interleaved addresses for four block sizes enabling it to quickly switch context to support different data services. The decoder is integrated to the AT-DMB...
CDMA 2000 1x EV-DO system can transmit the reverse traffic data at five different rates according to the channel quality and other affected factors. If the rate indicating information is missed or decoded unsuccessfully, the access network has to require the access terminal to transmit the information again. This paper refers the schemes used in the IS-95 system to solve the similar problems, and...
In this paper, we consider a MIMO multiuser system in a multipath fading channel. We design a blind receiver for a differential space-time coded modulation. A linear estimator projects the received signal onto the same subspace of the MMSE filter. The system works because of the differential encoding of the information matrices. Numerical results show that the blind receiver has the same performance...
We propose a novel communication scheme that combines rateless transmission and multilevel coding (MLC). The scheme is able to attain a throughput that is equal to the constellation-constrained channel capacity. It is particularly useful in cases where the celebrated bit-interleaved coded modulation (BICM) would leave significant gaps to the channel capacity and therefore, MLC is necessary for efficient...
In many dynamic spectrum access networks, it is necessary for secondary users to monitor the frequency band in which they are communicating so that they can determine if the primary user has begun transmission. Traditional sensing methods require the transmitters of the secondary users to be silent while spectrum monitoring is performed. Statistics that are derived easily in a communications receiver...
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