CDMA vs. LTE Network Technology

What is the difference between CDMA and LTE Network technologies?

CDMA stands for Code Division Multiple Access and LTE stands for Long Term Evolution. There is a difference between the two because CDMA is technology designed for multiple access and LTE is the technology for the next generation in cell phone communication known as 4G. Mobile networks make use of multiple access technology so they can add more users to each cell with the use of limited resources.

The earliest of these technologies were TDMA and FDMA. CDMA is actually the third of its kind and uses all the resources in the network for all the users. LTE was developed to handle a demand for higher rates of data and is part of the Third Generation Partnership Project (3GPP). It deals with such things as multi-media applications and Internet access for cell phone users to make mobile broadband a reality.

About CDMA

Communication systems use this technology for multiple access technique for cell phone usage. It is a combination of TDMA and FDMA technologies and is therefore a hybrid version of the two. In this technique there is a secured communication because it uses an individual pseudo-noise sequence for each subscriber to the service. This technique is called digital sequence spread spectrum technology. The original digital signal is converted to a higher frequency and this action tends to flatten or broaden the spread of the original spectrum in the frequency, also called a domain. As a result, the signal is visible as a noise but because of the pseudo-noise sequence the receiver does not hear this noise. This technology has drastically increased the number of subscribers that can exist in one cell. It also provides for a more secure communication link.

About LTE

This is the latest technology for mobile broadband. It started in 2004 as part of the 3GPP and was released on the market in 2009. It is considered to be the 4G and the best of all mobile communication networks. It uses the following radio technologies:

  • MIMO (Multiple Input Multiple Output)
  • OFDMA (Orthogonal Frequency Division Multiple Access)
  • SC- FDMA (Single Carrier FDMA)

Because it uses MIMO, the radio channel capacity in mobile communication systems are received by 3GPP so that it can achieve a higher rate of date. OFDMA refers to the multiple access technology for the LTE network with a downlink of about 100 Mbps.

The LTE downlink peaks at about 360 Mbps and the uplink peaks at about 86 Mbps. There is a channel bandwidth of 20 MHz and this is scalable from 1.25 MHz to higher limits. The time it takes for a return trip from the base to the mobile set is faster at 10 ms range.

There are similarities between SC FDMA and OFDMA. They both use DFT processing as recommended by the 3GPP for use as the method of uplink communication because of the efficiency and cost of the transmission of power.

Summary

  1. CDMA is a multiple access technology used in 3G networks. LTE is a 4G network.
  2. CDMA variations include CDMA one, CDMA 2000 and WCDMA to achieve higher rates of data. It is currently being used all over the world.
  3. LTE plans to use OFDMA to achieve higher downlink data rates.