Sub Channelization and Transmission Diversity in WiMAX Technology

Sub Channelization in WiMAX Technology

Another option within WiMAX technology in the uplink is Sub Channelization. Without sub channelization, narrow restrictions and requirement for cost effective WiMAX Customer Premise Equipment’s (CPEs), usually cause the link budget to be unbalanced, for that reason the system range to be up link is restricted. Sub channeling allows the link budget to be objective such that the system gains are parallel for both the up and down links. Sub channeling focuses the broadcasting power into fewer OFDM carriers; this is what boosts the system gain that can either be applied to widen the reach of the system, overcome the infrastructure penetration losses, and or lessen the power consumption of the Customer Premise Equipment’s (CPE). The use of sub channeling is promoted expansion in Orthogonal Frequency Division Multiple Access (OFDMA) to permit a more flexible use of resources that can maintain roaming or mobile operation. (Deepak Boppana, 2005)

Transmission Diversity in WiMAX Technology

Transmission Diversity formats are used for improvement of multi-path and reflections signals that arise in Non-Line-of-Sight (NLOS) environment. Transmission Diversity is an optional element in Wimax technology. The transmission diversity algorithms presented by WiMAX technology in both the transmitter and receiver significantly enhances the system accessibility. The WiMAX transmit diversity option uses space time coding to offer transmit source freedom; this decreases the weaken margin requirement and resist the interference with other devices. For receive transmission diversity, a variety of joining techniques are present to increase the accessibility of the system. For example, Maximum Ratio Combining (MRC) takes benefit of two separate receive chains to prevent fading and decrease path loss. Transmission diversity has verified to be a helpful tool for coping with the challenges of NLOS transmission. (Srikanth Mettukuru, 2007)

Leave a Reply

Your email address will not be published. Required fields are marked *