• The Journal of Korean Institute of Communications and Information Sciences
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• v.8 no.2
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• pp.43-47
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• 1983

The method of designing the polyphase network for the interpolation filter of the discrete signals is designed, the polyphase network consists of the hybrid FIR/IIR digital filter with the FIR filter and IIR filter which are designed by independent methods. It is showed that the proposed polyphase network is useful for the interpolation filter, by the estimation method using the white-gaussian noise.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.4
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• pp.673-682
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• 2010

This paper describes and analyzes a various generation methods of the mutually orthogonal polyphase sequences with low cross-correlation peak sidelobe and low autocorrelation peak sidelobe levels. The mutual orthogonality is the key requirement of multi-static or MIMO(Multi-Input Multi-Output) radar systems which provides the good target detection and tracking performance. The polyphase sequences, which are generated by SA(Simulated Annealing) and GA(Genetic Algorithm), have been analyzed with ACF(Autocorrelation Function) PSL(Peak Sidelobe Level) and CCF(Crosscorrelation Function) level at the matched filter output. Also, the ambiguity function has been introduced and simulated for comparing Doppler properties of each sequence. We have suggested the phase selection rule for applying multi-static or MIMO systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1566-1573
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• 2016

This paper presents a beam-forming receiver with polyphase In-phase/Quadrature-phase (I/Q) network for airborne communication. In beam-forming receiver, the insertion loss (IL) difference between input path increases the receiver noise figure (NF). The major element for generating IL difference is the impedance variation of phase shifter. In order to maintain a constant IL in every phase, this paper propose a lossless polyphase I/Q network based beam-forming receiver. The proposed lossless polyphase I/Q network has low Q-factor and high impedance for drive back-end VGA (Variable gain amplifier) block with low insertion loss. The 2-stage VGA controls in-phase and quadrature-phase amplitude level for vector summation. The proposed beam-forming receiver prototype is fabricated in TSMC $0.18{\mu}m$ CMOS process. The prototype cover the $360^{\circ}$ with $5.6^{\circ}$ LSB. The average RMS phase error and amplitude error is approximately $1.6^{\circ}$ and 0.3dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11C
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• pp.1059-1065
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• 2007

In this paper, we propose a class of polyphase signature sequences, whose general odd correlation properties are useful for M-ary phase signaling systems. The maximum magnitude of the general odd correlation functions of the proposed sequences are investigated and compared with those of FZC (Frank-Zadoff-Chu) sequences and those of EOE (equivalent odd and even correlation) sequences. The performance of the asynchronous M-ary phase signaling systems using the proposed sequences is simulated and compared with that using FZC sequences in direct sequence code division multiple access (DS/CDMA) systems. The performance of the system using the proposed sequence is shown to be better than that using FZC sequences when the multipath fading is in existence.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.11
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• pp.970-972
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• 2013

Signal acquisition performance is evaluated for the tiered polyphase code (TPC) which is proposed as a ranging signal structure for global navigation satellite systems (GNSSs). Compared to the tiered code (TC) which is adopted in European Union's GALILEO system, the TPC shows robust performance to frequency offset in acquiring signal. Therefore the TPC should have SNR gain in signal acquisition and can reduce computational complexity in the receiver. In this paper, we compare the signal detection probability of the TC and TPC under the same receiver architecture and GALILEO E5a-I signal parameters.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1707-1717
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• 1998

Polyphase filtering techniques is used to suppress the narrowband jammer signal such as USDC TDMA overlaying the band occupied by DS-CDMA system. In the proposed jammer suppression, the received signal is separated into 64 subchannels in two stages by polyphase filtering and the location of the narrowband jammer signal is determined by measuring each subchannel power and the contaminated subchannels are simply blocked. The $E_{b}/N_{0}$ 0/ improvement of the CDMA system from jammer suppession was outstanding. The $E_{b}/N_{0}$ degradation in comparison with a performance of no jammer is around 0.8dB in the worst case. The results are also compared with those of linear prediction jammer suppression. The implementation of the ployphase jammer suppression requires great amount of data processing and computation compared to linear predication filter. Thus it is more appropriate to implement with a ASIC rather than WITH several DSPs for user terminals of forward link.

• Journal of Broadcast Engineering
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• v.10 no.3
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• pp.340-347
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• 2005

This paper presents a polyphase down sampling based multiple description coding applied to H.264 video coding standard. For a given macroblock, a residual macroblock is calculated by motion estimation, and before applying DCT, quantization and entrophy coding of the H.264 coding process, the polyphase down sampling is applied to the residual macroblock to code in four separate descriptions. Experiments were performed for all the 9 test sequences of JVT SVC standardization in various packet loss patterns. Experimental results show that the proposed one gives 0.5 to 5 dB enhancement over an error-concealment based on the slice group map technolgoy.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.4
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• pp.286-292
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• 2004

This paper presents a polyphase filtered orthogonal frequency division multiplexing (PF-OFDM) technique. The proposed structure uses a modified discrete Fourier transform (MDFT) transmultiplexer to achieve greater spectral efficiency than an OFDM system, while preserving backward compatibility with it. The prototype PF-OFDM filter has excellent time and frequency localization properties, which matte it possible to eliminate a guard interval (or cyclic prefix) and easily suppress interchannel interference (ICI). This modulation technique uses a single DFT structure, in contrast to a MDFT transmultiplexer, which requires two DFT polyphase filter banks. The PF-OFDM modulation is .justified over multipath Rayleigh fading channels.

• ETRI Journal
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• v.29 no.1
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• pp.18-26
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• 2007

This paper presents an improved redundant picture coding method that efficiently enhances the error resiliency of H.264. The proposed method applies polyphase downsampling to residual blocks obtained from inter prediction and selectively encodes the rearranged residual blocks in the redundant picture coding process. Moreover, a spatial-temporal sample construction method is developed for the redundant coded picture, which further improves the reconstructed picture quality in error prone environments. Simulations based on JM11.0 were run to verify the proposed method on different test sequences in various error prone environments with average packet loss rates of 3%, 5%, 10%, and 20%. Results of the simulations show that the presented method significantly improves the robustness of H.264 to packet loss by 1.6 dB PSNR on average over the conventional redundant picture coding method.

• Journal of the Korean Institute of Telematics and Electronics
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• v.15 no.5
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• pp.25-28
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• 1978

This paper deals with the development research on the application of the principle of polyphase envelope detectioal),2) to extract the envelope from the complex physiological signal waveforms, which otherwise would be very difficult to observe and determine. In order to verify the developed system, the experimental results are included.