Circular Polarization Modulation for Digital Communication Systems

Conventional approaches of digital modulation schemes make use of amplitude, frequency and/or phase as modulation characteristic to transmit data. In this paper, we exploit circular polarization (CP) of the propagating electromagnetic carrier as modulation attribute which is a novel concept in digital communications. The requirement of antenna alignment to maximize received power is eliminated for CP signals and these are not affected by linearly polarized jamming signals. The work presents the concept of Circular Polarization Modulation for 2, 4 and 8 states of carrier and refers them as binary circular polarization modulation (BCPM), quaternary circular polarization modulation (QCPM) and 8-state circular polarization modulation (8CPM) respectively. Issues of modulation, demodulation, 3D symbol constellations and 3D propagating waveforms for the proposed modulation schemes are presented and analyzed in the presence of channel effects, and they are shown to have the same bit error performance in the presence of AWGN compared with conventional schemes while provide 3dB gain in the flat Rayleigh fading channel.

A New Irish? Problems of communication in modern Irish media and new speakers.

While the Gaeltacht (Irish speaking) areas of Ireland are geographically isolated from each other and relatively small in area, it is expected that the number of second language Irish speakers throughout the country should ensure the future of the language. Nevertheless, while the official standard grammar has been established for many decades, there is still a tendency in the spoken language to give precedence to regional dialectal variants in schools and the broadcast media which often raises barriers between native speakers themselves and between learners and native speakers.
All pupils in school in the Republic and many in Northern Ireland learn Irish and there has been a great increase in the number of pupils attending immersion Irish language Gaelscoileanna. But concern has been expressed about the phonetic and structural accuracy achieved in schools, all of which contributes to communication breakdown.
This paper discusses how a greater awareness of the link between phoneme and grapheme in Irish and the proposals for the Lárchanúint (Central Dialect) in the 1980s and current discussions on Caighdeán Leathan agus Caighdeán Cúng (Broad and Narrow Standard) would mitigate these concerns.

Further refinement of the nature of the communication impairment in Cornelia de Lange syndrome

Purpose – Research into the communication skills of individuals with Cornelia de Lange syndrome (CdLS) is extremely limited. This paper aims to evaluate the nature of these skills and impairments in CdLS using a detailed informant assessment of pre-verbal communication skills.
Design/methodology/approach – The study used the Pre-verbal Communication Schedule to evaluate communication skills in individuals with CdLS (n ¼ 14), aged five to14 years. The group was compared with a contrast group of individuals with Cri du Chat syndrome (CdCS; n ¼ 14) who were matched for age and intellectual ability.
Findings – A significant difference was identified in understanding non-vocal communication (p , 0.005), with the CdLS group showing a greater deficit. These findings indicate the presence of a syndrome-specific deficit in understanding non-verbal communication in individuals with CdLS and suggest that there may be a dissociation between the processing of verbal and non-verbal communication.
Originality/value – The findings indicate that, in many ways, these two syndrome groups are not dissimilar in terms of their communication skills. However, individuals with CdLS show a syndrome-specific deficit in understanding non-vocal communication relative to the CdCS group.

Blocking in children's causal learning depends on working memory and reasoning abilities.

A sample of 99 children completed a causal learning task that was an analogue of the food allergy paradigm used with adults. The cue competition effects of blocking and unovershadowing were assessed under forward and backward presentation conditions. Children also answered questions probing their ability to make the inference posited to be necessary for blocking by a reasoning account of cue competition. For the first time, children's working memory and general verbal ability were also measured alongside their causal learning. The magnitude of blocking and unovershadowing effects increased with age. However, analyses showed that the best predictor of both blocking and unovershadowing effects was children's performance on the reasoning questions. The magnitude of the blocking effect was also predicted by children's working memory abilities. These findings provide new evidence that cue competition effects such as blocking are underpinned by effortful reasoning processes. 

BER Driven Synthesis for Directional Modulation Secured Wireless Communication

Directional modulation (DM) is a recently introduced technique for secure wireless transmission using direct physical layer wave-front manipulation. This paper provides a bit error rate (BER)-based DM array synthesis method. It is shown for the first time that the standard constellation mappings in In-phase and Quadrature (IQ) space to a pre-specified BER can be exactly achieved along a given specified spatial direction. Different receiver capabilities are investigated and different assessment metrics for each case are discussed. The approach is validated for a 1 × 4 element dipole array operating at 1 GHz.

Secure Communication in Cellular Networks: The Benefits of Millimeter Wave Mobile Broadband

This paper proposes millimeter wave (mmWave) mobile broadband for achieving secure communication in downlink cellular network. Analog beamforming with phase shifters is adopted for the mmWave transmission. The secrecy throughput is analyzed based on two different transmission modes, namely delay-tolerant transmission and delay-limited transmission. The impact of large antenna arrays at the mmWave frequencies on the secrecy throughput is examined. Numerical results corroborate our analysis and show that mmWave systems can enable significant secrecy improvement. Moreover, it is indicated that with large antenna arrays, multi-gigabit per second secure link at the mmWave frequencies can be reached in the delay-tolerant transmission mode and the adverse effect of secrecy outage vanishes in the delay-limited transmission mode.