Multi-Band Carrier Code Division Multiple Access for 4g Mobile System with Improved Signal Quality
World Applied Sciences Journal 12 (3): 330-335, 2011 ISSN 1818-4952 © IDOSI Publications, 2011
Multi-band Carrier Code Division Multiple Access for 4G Mobile System with Improved Signal Quality
Jalal J. Hamad Ameen and Widad Binti Ismail School of Electrical and Electronics, Universiti Sains Malaysia, Pulau Penang, 11800, Malaysia
Abstract: The proposed frequency band for a 4G mobile system is 2 to 8 GHz, while the proposed access for the system is MC-CDMA / OFDM. In this paper, a new access technique has been proposed, with the bandwidth of the system divided into ten sub-bands. Each sub-band has40 channels and the access is a multiband of the carrier CDMA (MBC-CDMA). The proposed access provides more flexibility for the base stations to re-use the frequency than MC-CDMA because of the use of frequency hopping between the channels as well as the sub-bands. The hopping sequence depends on the spreading code. A comparison of the performance of the proposed access technique with MC-CDMA showed that there is an improvement in signal quality and BER performance, as an application, this proposed multiple access technique suitable for 4G mobile air interface for further interference reduction and in improvement in signal quality. Key words: 4G mobile system % MC-CDMA % Frequency Hopping % MBC-CDMA INTRODUCTION There are a number of multiple access techniques to transmit several user signals simultaneously through one channel. In general, what are used are three-dimensional time, frequency and code. The use of multiple frequencies at the same time and one code, if digital, is referred to as frequency division multiple access (FDMA). On the other hand, the use of different time slots in one frame with the same frequency is referred to as time division multiple access (TDMA). Finally, the transmission of signals at the same time using the same frequency with different spreading codes is referred to as code division multiple access (CDMA). Each of the multiple access
Multi-band Carrier Code Division Multiple Access for 4G Mobile System with Improved Signal Quality
Jalal J. Hamad Ameen and Widad Binti Ismail School of Electrical and Electronics, Universiti Sains Malaysia, Pulau Penang, 11800, Malaysia
Abstract: The proposed frequency band for a 4G mobile system is 2 to 8 GHz, while the proposed access for the system is MC-CDMA / OFDM. In this paper, a new access technique has been proposed, with the bandwidth of the system divided into ten sub-bands. Each sub-band has40 channels and the access is a multiband of the carrier CDMA (MBC-CDMA). The proposed access provides more flexibility for the base stations to re-use the frequency than MC-CDMA because of the use of frequency hopping between the channels as well as the sub-bands. The hopping sequence depends on the spreading code. A comparison of the performance of the proposed access technique with MC-CDMA showed that there is an improvement in signal quality and BER performance, as an application, this proposed multiple access technique suitable for 4G mobile air interface for further interference reduction and in improvement in signal quality. Key words: 4G mobile system % MC-CDMA % Frequency Hopping % MBC-CDMA INTRODUCTION There are a number of multiple access techniques to transmit several user signals simultaneously through one channel. In general, what are used are three-dimensional time, frequency and code. The use of multiple frequencies at the same time and one code, if digital, is referred to as frequency division multiple access (FDMA). On the other hand, the use of different time slots in one frame with the same frequency is referred to as time division multiple access (TDMA). Finally, the transmission of signals at the same time using the same frequency with different spreading codes is referred to as code division multiple access (CDMA). Each of the multiple access
References: 1. Eric Lawrey, 2001. “The suitability of OFDM as a modulation technique for wireless telecommunications, with a CDMA comparison ”PhD thesis, Computer systems engineering at James Cook University, 334 World Appl. Sci. J., 12 (3): 330-335, 2011 2.