BUKU ABSTRAK - Universiti Putra Malaysia

Superposition Coding with Unequal Error Protection for the Overloaded CDMA
System
Assoc. Prof. Dr. Nor Kamariah Noordin
Borhanuddin Mohd. Ali, Ng Chee Kyun and Yaseen H. Tahir
Faculty of Engineering, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 6181; nknordin@eng.upm.edu.my
Keywords: UEP, SIC, superposition coding, overloaded CDMA
Sign Based Automating Electrical Household Appliances
Keywords: sign, recognition, appliances, smart home, DSP
Assoc. Prof. Dr. Nor Kamariah Noordin
Borhanuddin Mohd. Ali, Ng Chee Kyun and Ng Wei Lun
Faculty of Engineering, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 6181; nknordin@eng.upm.edu.my
203
Science, Technology & Engineering
The overloaded CDMA techniques are used in CDMA systems in order to accommodate the number of users
more than the spreading factor N. In this invention, the superposition coding CDMA (SPC-CDMA) is proposed
as one of the overloaded CDMA techniques. In this proposed technique, the users in the system are divided
into N groups and each group consists of K users. The possibility of the power control in the base station (BS)
is used to provide unequal error protection (UEP) to the K users. The signals of the same group are spread by
using a distinct spreading sequence and transmitted across AWGN channel. At the received side, a UEP adapted
of ordered successive interference cancellation (O-SIC) technique is used to extract the desired data from the K
users’ signals in the same group. The theoretical and simulation analysis show the proposed technique has better
performances in AWGN channel compared to other overloaded CDMA techniques. The proposed SPC-CDMA
technique maximises the user capacity by K-fold without exploiting more resources (frequency, time or code)
with only 1 dB cost of SNR degradation at BER of 10-3, which related to conventional DS-CDMA system. At the
same power constraint, SPC-CDMA provides the same user capacity of other overloaded CDMA with only 0.7
dB gain in SNR. It also affords twofold of user rate with the same values of N and K.
In this invention, a simple sign based automating controller for various household appliances is presented.
The household appliances that can be automated by using this controller ranged from simple lightings to complex
electronic devices. The invented system consists of three main components: the sign based data glove system,
the household appliances sensing system, and the sign based recognition management system for data collection
and processing. The developed data glove has the capability to measure the finger sign postures using specific
sensor attached to each finger. Theoretically, the five fingers per hand can create many different signs due to
the many possibilities of performing various sign posture. Each sign posture can be used as a command for the
controller. The attached microcontroller in the data glove receives the sensors’ signal data associated to a given
sign. These data are diagnosed and translated by using digital signal processing (DSP). The analysed data are then
transmitted to the data center using communication transceiver module. The recognition management system
data center matches the received glove data with associated command data using matching algorithm. When
the data are matched, the command data will be sent to the related household appliance device to execute the
given commands through communication transceiver module. This invention has been proven to be suitable for
disabled and elderly people due to its flexible properties and ease of usage. This flexibility allows user to change
the command of the system based on the user’s capability of performing the sign posture.