Digitalized Cross-Polarization Interference Canceller for Multilevel Digital Radio

Matsue, Hiroyuki; Ohtsuka, Hiroyuki; Murase, T.

doi:10.1109/jsac.1987.1146544

Cited by 15 publications

(4 citation statements)

References 2 publications

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“…In [164], comparative study of 16, 32, 64, 128-QAM constellations at 140 Mbps by considering both linear and non-linear equalizers was presented. In [165], highly precise cross-polarization interference canceler was developed by using digital transversal filter and performance of 256-QAM at 12.5 Mbps was examined. In [166], authors performed a simulation case study of M -ary QAM constellations for a high capacity digital radio link, subjected to frequency selective fading with different types of channel encoding.…”

Section: A Mobile Communicationsmentioning

confidence: 99%

A Survey on Higher-Order QAM Constellations: Technical Challenges, Recent Advances, and Future Trends

Singya

Shaik

Kumar

et al. 2021

IEEE Open J. Commun. Soc.

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Communication system's performance is sensitive to bandwidth, power, cost etc. There have been various solutions to improve the performance, out of them, one of the fundamental solutions over the years is design of optimum modulation schemes. As the research on beyond 5G heats up, we survey and explore power and bandwidth efficient modulation schemes for the next generation communication systems in details. In the existing literature, initially square quadrature amplitude modulation (SQAM) was considered. However, only square constellations are not sufficient for varying channel conditions and rate requirements, thus, efficient odd power of 2 constellations were introduced. For odd power of 2 constellations, rectangular QAM (RQAM) is most commonly used. However, RQAM is not a good choice and modified cross QAM (XQAM) constellation is preferred which provides improved power efficiency over RQAM due to its energy efficient two dimensional (2D) structure. The increasing demand for high data-rates has further encouraged research towards more compact 2D constellations which leads to hexagonal lattice structure based hexagonal QAM (HQAM) constellations. In this work, various QAM constellations are discussed and detailed study of star QAM, XQAM, and HQAM is presented. Generation, peak and average energies, peak-to-average-power ratio, symbol-error-rate, decision boundaries, bit mapping, Gray code penalty, and bit-error-rate of star QAM, XQAM, and HQAM constellations for different constellation orders are presented. Finally, a comparative study of various QAM constellations is presented which justifies the supremacy of HQAM over other QAM constellations for various wireless communication systems and a potential modulation scheme for future standards.

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Section: A Mobile Communicationsmentioning

confidence: 99%

A Survey on Higher-Order QAM Constellations: Technical Challenges, Recent Advances, and Future Trends

Singya

Shaik

Kumar

et al. 2021

IEEE Open J. Commun. Soc.

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“…However, microwave backhaul links generally require line‐of‐sight (LoS) propagation. Various methods for improving spectral efficiency have been studied in previous works . Polarization division multiplexing (PDM), which employs independent datasets from two orthogonal polarizations (such as vertical and horizontal polarizations) at the same frequency to double the total data throughput, was used in .…”

Section: Introductionmentioning

confidence: 99%

“…Polarization division multiplexing (PDM), which employs independent datasets from two orthogonal polarizations (such as vertical and horizontal polarizations) at the same frequency to double the total data throughput, was used in . Cross‐polarization isolation must be sufficiently large to improve the performance of PDM systems; this is accomplished by using two separate antennas , an orthomode transducer (OMT) device or a cross polarization interference cancellation (XPIC) algorithm . Previous works determined that the MIMO technique can be applied in a LoS environment if the transmitting and receiving antennas are properly placed and separated .…”

Section: Introductionmentioning

confidence: 99%

16-QAM OFDM-Based K-Band LoS MIMO Communication System with Alignment Mismatch Compensation

Kim¹,

Kim²,

Kang³

et al. 2017

ETRI Journal

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This paper presents a novel K-band (18 GHz) 16-quadrature amplitude modulation (16-QAM) orthogonal frequency-division multiplexing (OFDM)-based 2 3 2 line-of-sight multi-input multi-output communication system. The system can deliver 356 Mbps on a 56 MHz channel. Alignment mismatches, such as amplitude and/or phase mismatches, between the transmitter and receiver antennas were examined through hardware experiments. Hardware experimental results revealed that amplitude mismatch is related to antenna size, antenna beam width, and link distance. The proposed system employs an alignment mismatch compensation method. The openloop architecture of the proposed compensation method is simple and enables facile construction of communication systems. In a digital modem, 16-QAM OFDM with a 512-point fast Fourier transform and (255, 239) Reed-Solomon forward error correction codecs is used. Experimental results show that a bit error rate of 10 À5 is achieved at a signal-to-noise ratio of approximately 18.0 dB.

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“…In order to efficiently use PS in FAP problems, it is required to eliminate or completely cancel cross-polarization [4]. If this is available, then several techniques exist to extend the FAP problem with polarization (FAPP), e.g., in [5] a tabu search based solution is proposed to solve this problem.…”

Section: Introductionmentioning

confidence: 99%

Efficiency of frequency duplexing used for interference elimination

Jocha

Gódor

2014

2014 IEEE Wireless Communications and Networking Conference (WCNC)

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Careful planning of wireless networks is essential to provide reliable communication, especially that microwave links are frequently chosen to interconnect access points within networks. The optimization of such networks belongs to the frequency assignment problems and focuses on setting polarization of the links or allocating the channels in a frequency duplex to reduce or eliminate the interference that might occur between links. In this paper we are aiming to reveal the unexpected difference between these two well-studied problems if the sharpness of the applied beam widths is relaxed. We provide graph theory based analysis and reveal the main differences between frequency duplexing and polarization setting from mathematical point of view. We give numerical bounds for efficiency and show traps of algorithmic solutions working with interference graphs.

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Digitalized Cross-Polarization Interference Canceller for Multilevel Digital Radio

Cited by 15 publications

References 2 publications

A Survey on Higher-Order QAM Constellations: Technical Challenges, Recent Advances, and Future Trends

A Survey on Higher-Order QAM Constellations: Technical Challenges, Recent Advances, and Future Trends

16-QAM OFDM-Based K-Band LoS MIMO Communication System with Alignment Mismatch Compensation

Efficiency of frequency duplexing used for interference elimination

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