Digital Signal Modulation

What is the difference between ASK, FSK, and PSK modulation techniques in digital signal processing?

In digital signal processing, ASK (Amplitude Shift Keying), FSK (Frequency Shift Keying), and PSK (Phase Shift Keying) are different modulation techniques used to encode digital data onto carrier signals. ASK modulates the amplitude of the carrier signal to represent binary data, FSK modulates the frequency of the carrier signal, and PSK modulates the phase of the carrier signal. Each technique has its own advantages and disadvantages in terms of complexity, bandwidth efficiency, and susceptibility to noise.

What is the difference between ASK, FSK, and PSK modulation techniques in digital signal processing?

How does the concept of symbol rate relate to digital signal modulation?

The concept of symbol rate in digital signal modulation refers to the number of symbols or signal changes transmitted per second. Symbol rate is closely related to the data rate of a digital communication system, as it determines how quickly data can be transmitted using modulation techniques. A higher symbol rate allows for a higher data rate, but it also requires more bandwidth and can be more susceptible to noise and interference.

SPS BSI Webinar: MIR137 polygenic risk for schizophrenia and ephrin-regulated pathway: Role in brain morphology

Date: 31 May 2024 Time: 1:00 PM ET (New York Time) Presenter(s): Dr. Elisabetta C. del Re Meeting information: Meeting number: 2632 269 5821 Password: hPFwSbt7H36 (47397287 when dialing from a phone or video system) Join by phone: +1-415-655-0002 US Toll Access code: 263 226 95821 Join us Friday, May 31st, 2024, at 1:00 PM ET for an exciting virtual talk by Dr. Elisabetta C. del Re entitled: “MIR137 polygenic risk for schizophrenia and ephrin-regulated pathway: Role in brain morphology” as part of the activities of the Brain Space Initiative, co-sponsored by the Center for Translational Research in Neuroimaging and Data Science (TReNDS) and the Data Science Initiative, IEEE Signal Processing Society. Abstract MIR137 polygenic risk for schizophrenia and ephrin-regulated pathway: Role in brain morphology Background/Objective. Enlarged lateral ventricle (LV) volume and decreased volume in the corpus callosum (CC) are hallmarks of schizophrenia (SZ). We previously showed an inverse correlation between LV and CC volumes in SZ, with global functioning decreasing with increased LV volume. This study investigates the relationship between LV volume, CC abnormalities, and the microRNA MIR137 and its regulated genes in SZ, because of MIR137’s essential role in neurodevelopment. Results: Increased LV volumes and decreased CC central, mid-anterior, and mid-posterior volumes were observed in SZ probands. The MIR137-regulated ephrin pathway was significantly associated with CC:LV ratio, explaining a significant proportion (3.42 %) of CC:LV variance, and more than for LV and CC separately. Other pathways explained variance in either CC or LV, but not both. CC:LV ratio was also positively correlated with Global Assessment of Functioning, supporting previous subsample findings. SNP-based heritability estimates were higher for CC central:LV ratio (0.79) compared to CC or LV separately. Discussion: Our results indicate that the CC:LV ratio is highly heritable, influenced in part by variation in the MIR137-regulated ephrin pathway. Findings suggest that. Biography Elisabetta del Re is an Assistant Professor of Psychiatry at Harvard Medical School and Principal Investigator of NIMH funded research. She has multidisciplinary training in basic science, mental health, neuroimaging, including electrophysiology, and genetics. She holds a MA and PhD in Biochemistry and Experimental Pathology from Boston University; A MA in Mental Health from BGSP. Dr. del Re’s interest is in understanding psychosis and other serious mental illnesses, by looking at the genetics informing neural processes. Recommended Articles: Blokland, Gabriëlla Antonina Maria, et al. "MIR137 polygenic risk for schizophrenia and ephrin-regulated pathway: Role in lateral ventricles and corpus callosum volume." International Journal of Clinical and Health Psychology 24.2 (2024): 100458. (Link to Paper) Heller, Carina, et al. "Smaller subcortical volumes and enlarged lateral ventricles are associated with higher global functioning in young adults with 22q11. 2 deletion syndrome with prodromal symptoms of schizophrenia." Psychiatry Research 301 (2021): 113979. (Link to Paper)

Posted by on 2024-05-29

(ICME 2025) 2025 IEEE International Conference on Multimedia and Expo

Date: 30 June-4 July 2025 Location: Nantes, France Conference Paper Submission Deadline: TBD

Posted by on 2024-05-28

Distinguished Lecture: Prof. Woon-Seng Gan (Nanyang Technological University, Singapore)

Date:  7 June 2024 Chapter: Singapore Chapter Chapter Chair: Mong F. Horng Title: Augmented/Mixed Reality Audio for Hearables: Sensing, Control and Rendering

Posted by on 2024-05-21

Distinguished Lecture: Prof. Dr. Justin Dauwels (TU Delft)

Date: 4-5 November 2024 Chapter: Tunisia Chapter Chapter Chair: Maha Charfeddine Title: Generative AI

Posted by on 2024-05-21

Can you explain the advantages and disadvantages of using QAM modulation in digital communication systems?

Quadrature Amplitude Modulation (QAM) is a modulation technique that combines both amplitude and phase modulation to encode digital data onto a carrier signal. The advantages of using QAM include higher data rates, improved spectral efficiency, and robustness against noise. However, the main disadvantage of QAM is its increased complexity compared to simpler modulation techniques like ASK or FSK.

Applications of Digital Audio Signal Processing in Telecommunications

Can you explain the advantages and disadvantages of using QAM modulation in digital communication systems?

How does the process of demodulation work in the context of digital signal modulation?

Demodulation is the process of extracting the original digital data from a modulated carrier signal. In digital signal modulation, demodulation involves reversing the modulation process by detecting changes in amplitude, frequency, or phase of the carrier signal to recover the encoded data. Demodulation is essential for accurately decoding and interpreting the transmitted information in a digital communication system.

Real-Time Audio Processing

What role does the Nyquist theorem play in determining the maximum data rate for a digital communication system using modulation?

The Nyquist theorem plays a crucial role in determining the maximum data rate for a digital communication system using modulation. According to the Nyquist theorem, the maximum data rate of a communication system is limited by the bandwidth of the channel and the symbol rate used for modulation. By ensuring that the symbol rate is less than or equal to half the bandwidth of the channel, the Nyquist theorem helps prevent signal distortion and interference in digital communication systems.

What role does the Nyquist theorem play in determining the maximum data rate for a digital communication system using modulation?
How do factors such as noise and interference impact the performance of digital signal modulation techniques?

Factors such as noise and interference can significantly impact the performance of digital signal modulation techniques. Noise introduced during transmission can distort the modulated signal, leading to errors in data recovery during demodulation. Interference from other signals or sources can also disrupt the communication process, affecting the reliability and accuracy of the transmitted data. Techniques like error correction coding and signal processing algorithms are used to mitigate the effects of noise and interference in digital communication systems.

What are some common applications of digital signal modulation in modern communication systems?

Digital signal modulation is widely used in modern communication systems for various applications, including wireless communication, satellite communication, digital broadcasting, and data transmission over networks. Modulation techniques like ASK, FSK, PSK, and QAM are essential for encoding and transmitting digital data efficiently and reliably. By modulating digital signals onto carrier waves, communication systems can achieve higher data rates, improved spectral efficiency, and better resistance to noise and interference.

What are some common applications of digital signal modulation in modern communication systems?

Audio signal encryption in secure telecommunications can be achieved through various methods such as Advanced Encryption Standard (AES), Rivest Cipher (RC4), Data Encryption Standard (DES), Triple Data Encryption Standard (3DES), and Public Key Infrastructure (PKI). These encryption techniques utilize algorithms to scramble the audio data, making it unreadable to unauthorized users. Additionally, techniques like frequency hopping spread spectrum and spread spectrum modulation can be employed to further secure the transmission of audio signals. By combining these methods, telecommunications systems can ensure the confidentiality and integrity of audio communications, protecting sensitive information from interception or tampering.

Audio quality assessment in telecommunication systems can be conducted using various methods such as objective measurements, subjective evaluations, and perceptual models. Objective measurements involve analyzing parameters like signal-to-noise ratio, frequency response, and distortion levels to quantitatively assess audio quality. Subjective evaluations, on the other hand, rely on human listeners to provide feedback on perceived audio quality through methods like Mean Opinion Score (MOS) tests. Perceptual models use algorithms to simulate human auditory perception and predict how listeners will perceive audio quality based on factors like codec performance and network conditions. By combining these methods, telecommunication systems can ensure high-quality audio transmission for optimal user experience.

The impact of packet-switched networks on audio signal quality can vary depending on various factors such as network congestion, packet loss, latency, and jitter. Packet-switched networks break down audio data into smaller packets for transmission, which can lead to packets arriving out of order or being lost altogether. This can result in degraded audio quality, including issues such as distortion, dropouts, and delays. Quality of Service (QoS) mechanisms can help prioritize audio packets to minimize these issues, but the overall impact on audio signal quality in packet-switched networks is still a concern for applications requiring real-time, high-fidelity audio transmission. Additionally, factors such as network bandwidth, codec efficiency, and error correction techniques can also influence the overall audio quality in packet-switched networks.

The function of an audio packet jitter buffer in VoIP systems is to mitigate the effects of network congestion and variability in packet arrival times, ensuring a smooth and consistent audio stream during voice calls. By temporarily storing incoming audio packets and releasing them at a steady rate, the jitter buffer helps to minimize packet loss, delay, and distortion. This buffer also plays a crucial role in synchronizing audio packets to maintain the quality of the voice communication. Additionally, the jitter buffer can adapt dynamically to changing network conditions, adjusting its size and delay parameters to optimize performance. Overall, the jitter buffer is an essential component in VoIP systems that enhances the reliability and quality of voice transmissions over IP networks.

Audio latency in interactive telecommunication applications is managed through a combination of techniques such as buffer size optimization, jitter buffering, packet prioritization, and codec selection. By adjusting the buffer size, developers can minimize the delay between audio input and output. Jitter buffering helps smooth out variations in packet arrival times, reducing latency spikes. Packet prioritization ensures that audio packets are given precedence over other types of data, further reducing latency. Additionally, selecting efficient codecs can help minimize the processing time required for encoding and decoding audio data, ultimately improving overall latency performance in interactive telecommunication applications.