KM Portal

Digital Multiplexing Techniques
Research Output | Dar Al-hikmah Library | IIUM Only

Multiplexing techniques are broadly classified as analogue and digital, digital being the latest. Time Division Multiplexing (TDM) and Statistical TOM are most commonly used digital multiplexing techniques. The TOM is a detenninistic method of multiplexing various sources in pre-determined fixed slots. Statistical TDM, (STDM) uses dynamic method of

Networking Issue
Research Output | Dar Al-hikmah Library | IIUM Only

All communication networks use or going to use packet based communications that intrinsically use STDM for communication. No user is going to have a fixed time slot instead, a slot is allocated on a demand basis or activity basis. The packet discarding is a new' concept in networking, in this chapter a random packet discarding is explained.STAT

LPC Envelope Difference Criterion and Multiplexing Efficiency
Research Output | Dar Al-hikmah Library | IIUM Only

Linear Predictive Coding (LPC) envelop difference is a technique that exploits envelop of each frame. This is a frequency domain measure in which for each active speech frame and its reconstructed frame is used to find out the differences in their envelops. This LPC difference measures can be utilised for the STDM design purpose. This chapter is de

Energy Ad a Criterion for Frame Discarding and Multiplexing Efissiency
Research Output | Dar Al-hikmah Library | IIUM Only

To design a STOM on the criterion of energies of each frame is one of the popUlar methods. In this each frames energy is calculated, a frame with lower energy is the best candidates among all users' speech frames. Dropping the frame with lmvest energy may degrade quality at its minimum as compared to the higher energy signals. This is also perc

Simulation of Speech Activities Using Markov Model
Research Output | Dar Al-hikmah Library | IIUM Only

A speech signal can be active or non-active; in one of the nvo states in anyone time, or for a frame of speech. The duration ofthe both active and non-active parts can varies based upon the modes of speech (monologue and dialogue). The activities or non-activities of the speech can be modelled by using Markov Model, in this scenario a two state mod

Concept of Frames Discarding and Multiplexing Efficiency
Research Output | Dar Al-hikmah Library | IIUM Only

At low bit rates speech is coded frame by frame, each frame of a size of 20-30ms. Perceptually, each frame may be different, depends upon the speech signal properties (voiced or unvoiced). The frames with lower perception may be one of the potential candidates to be dropped and reconstructed to maximize the bandwidth of the systems. This chapter ex

Measured Temporal Parameters
Research Output | Dar Al-hikmah Library | IIUM Only

Speech communication is often realised by two ways monologue and dialogue modes. The temporal (time) attributes, such as active and non-active parts of both of these varies because of the nature of the modes. In monologue modes of speech communication activity of each user remains 80% and 20% are the silences and in dialogue (conversational) modes

Design of a Low Bit Rate Stdm Multiplexing
Research Output | Dar Al-hikmah Library | IIUM Only

A low bit rate STDM multiplexer architecture design for thing route channels is provided in this chapter. A thin route communication channel is able to transmit 64Kbps to 128Kbps. Allowing compressed speech using STDM maximize the bandwidth by allowing more users than the capacity ofthe channel. The design provided in this chapter is based upon, co

Packet Loss and Frame Substitution Techniques
Research Output | Dar Al-hikmah Library | IIUM Only

In packetized speech communication the packet loss occurs. The packets can also be forced to drop in situations when traffic load increase at the multiplexing end. The dropped packets can be substituted at the demultiplexing end. To do so frame substitution techniques can be utilised to mitigate the effects oflost packets. In this chapter packet lo

Multiplexing and Operational Scenarios
Research Output | Dar Al-hikmah Library | IIUM Only

The design of multiplexer operation can be based upon certain simulation parameters. In this chapter a design of STDM is based upon some parameters considering a 64 Kbps satellite channel. Allowing each user a capacity of 6.4kbps, 10 users can be multiplexed in a normal situation. Using VAD and packet discarding for each of the users allmv more use

Category

KCDIOM

Type

KCDIOM

KM Portal