The author presents a proposal for solving the problem of reduced performance of coded modulation due to colored channel noise by whitening the noise with an added noise predictor in the decision-feedback equalizer (D...
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The author presents a proposal for solving the problem of reduced performance of coded modulation due to colored channel noise by whitening the noise with an added noise predictor in the decision-feedback equalizer (DFE). This also has the benefit of increasing the nominal SNR. The resulting equalizer has a structure encompassing as a special case the noise-predictive DFE proposed earlier by others. Several numerical examples are provided to illustrate the digital subscriber line transmission performance with the new noise-predictive DFE. It is shown that the added noise predictor improves the transmission performance in two ways: first, it decorrelates the noise, and second, it decreases the noise power by its prediction gain.< >
Space-Time trellis-coded modulation (ST-TCM) which combines modulation and coding in a single entity delivers exceptional performance in static enviroment such as AWGN and flat fading channels. On the other hand, bit-...
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Space-Time trellis-coded modulation (ST-TCM) which combines modulation and coding in a single entity delivers exceptional performance in static enviroment such as AWGN and flat fading channels. On the other hand, bit- interleaved coded modulation (BICM) which gives up the joint decoder/demodulator architecture in favor of two separate entities outperforms ST-TCM in selective fading channels, but suffers performance loss in static channels. This paper proposes a space-time serial concatenated coding schemes which consist of two ";simple"; constituent encoders and an interleaver namely: ST serial concatenated Turbo-coded modulation (ST-SCTCM). Both theory and simulation results demonstrate that ST-SCTCM outperforms either ST-TCM or BICM across different channel conditions.
A comparative evaluation of the performance of Manchester coded PSK (MC-PSK), phase shift keying return to zero (PSK-RZ) and phase shift keying varied phase (PSK-VP) anti-multipath modulation techniques is presented. ...
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A comparative evaluation of the performance of Manchester coded PSK (MC-PSK), phase shift keying return to zero (PSK-RZ) and phase shift keying varied phase (PSK-VP) anti-multipath modulation techniques is presented. A two-ray propagation channel model using various delay spread values has been employed. The effect of spectral shaping of the transmitted signal on the BER performance of each of these modulation schemes, using Butterworth lowpass and square-root raised cosine premodulation filters, is investigated. The BER performance results obtained using these modulation techniques are compared with that of differential phase-shift keying (DPSK) modulation. It is shown that for a frequency non-selective fading channel, the performance of the anti-multipath modulation schemes is comparable to that of simple DPSK. However as the channel becomes frequency selective, the performance of the anti-multipath modulation systems improves beyond that provided by the DPSK system.< >
To enable us to affordably teach software defined radio at the undergraduate level, we developed a low cost system that allows realistic hardware projects and demonstrations. This new board connects a Texas Instrument...
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To enable us to affordably teach software defined radio at the undergraduate level, we developed a low cost system that allows realistic hardware projects and demonstrations. This new board connects a Texas Instruments C67x DSP starter kit (DSK) to an analog devices AD9857 quadrature modulator. This modulator is capable of operating at up to 200 million samples per second (MS/s), with a carrier (or intermediate frequency) of up to 80 MHz. Baseband 14-bit in-phase and quadrature (I/Q) data are presented to the modulator, which can be programmed to interpolate the data at rates from 4x to 252x. The AD9857 is interfaced to the DSK using an Altera Cyclone FPGA which provides queuing of the I/Q data and the logic for control/programming of the modulator. This paper describes the associated hardware and software issues and briefly describes recommended classroom use.
Summary from only given. In digital holographic data storage data modulation coding, data interleaving, and error correction are usually implemented in addition to conventional holography and multiplexing. The perform...
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Summary from only given. In digital holographic data storage data modulation coding, data interleaving, and error correction are usually implemented in addition to conventional holography and multiplexing. The performance of the holographic disk digital data storage system is determined by several major factors, most notably, by the optical parameters (such as the imaging NA), material performance (dynamic range or M/#, scattering, and thickness), as well as available laser power.
Digital Audio Broadcasting (DAB) was developed by the European Eureka-147 project. This system has many technical advantages of modulation coding (COFDM), error correction (Viterbi decoding) and source coding (MUSICAM...
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Digital Audio Broadcasting (DAB) was developed by the European Eureka-147 project. This system has many technical advantages of modulation coding (COFDM), error correction (Viterbi decoding) and source coding (MUSICAM). DAB is used for high speed data broadcasting to mobile vehicles and can provide CD quality audio programs and various data to drivers. The prototype DAB receiver is designed using multiple general purpose DSPs and consists of an RF part, OFDM decoder, Viterbi decoder and MUSICAM decoder. The DAB system is described and the first prototype DAB receiver is introduced. In addition, our first field testing in Toronto and DAB future possibilities are also described.< >
In this paper, 8-ary Elliptical Phase Shift Keying (8EPSK) Trellis-Coded modulation and set partitioning based on the sum of soft metric distance are proposed and developed. The criterion to design and search for good...
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In this paper, 8-ary Elliptical Phase Shift Keying (8EPSK) Trellis-Coded modulation and set partitioning based on the sum of soft metric distance are proposed and developed. The criterion to design and search for good TCM codes is also presented. The performance of 8EPSK-TCM has been evaluated through Matlab simulation in terms of BER. The results show that the performance of 8EPSK-TCM outperforms the conventional 8PSK-TCM and 8EPSK convolutional codes.
In this study we analyze the synergy effects among ARQ and Hybrid ARQ with rate-adaptive mechanisms. We present several coding and decoding schemes and link adaptation techniques for rate-adaptive transmission, design...
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In this study we analyze the synergy effects among ARQ and Hybrid ARQ with rate-adaptive mechanisms. We present several coding and decoding schemes and link adaptation techniques for rate-adaptive transmission, designed to combat noise, and we discuss their performance. We describe approaches for searching and selecting the best modulation and coding scheme (MCS) based on channel quality information (CQI). Hybrid ARQ using convolutional and punctured convolutional codes is used with variable re-transmission packet size and code rate according to CQI. Attractive simulation results are issued and they may be used as a basis for performance trade-off.
This paper presents a symbol synchronization algorithm in the multi-mode orthogonal frequency division multiplexing (OFDM) systems. Efficient system reconfiguration algorithm applying to the adaptive modulation and co...
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This paper presents a symbol synchronization algorithm in the multi-mode orthogonal frequency division multiplexing (OFDM) systems. Efficient system reconfiguration algorithm applying to the adaptive modulation and coding (AMC) method is also presented. The algorithm for the symbol synchronization uses the shorter repetition period for computing correlation values than existing methods. It can reduce the computational complexity and the estimation delay time. We confirm the performance of the algorithm by using the baseband platform equipped with TMS320C6416 DSP chip. After the synchronization process, we propose the efficient AMC method that use throughput based on the channel characteristic. It changes the modulation process and coding rate dynamically. We measure the throughput of the AMC applied to the system reconfiguration algorithm.
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