CDMA vs WCDMA- A comparison review

Ever wondered how 2G’s CDMA tech differs from 3G’s WCDMA? If so, here is an elaborate review with an in depth comparison of the two. Take a look.

Multiple Access Schemes are the foundation of cellular technologies. With these, many users can access a cellular system simultaneously without interference problems or issues with access. While cellular systems utilize 4 main technologies, FDMA, TDMA, CDMA and OFDMA, we will focus on the more recent Code Division Multiple Access and its successor: Wide CDMA.

Below, we compare both of these technologies: highlighting some of their history, what each of these has to offer, and how they have contributed to the evolution of commercial cellular communications. Here is the comprehensive review of the older CDMA technology, compared to WCDMA.

What are the differences between CDMA and WCDMA?

 
CDMA
WCDMA (Winner) 
In full
Code Division Multiple Access
Wideband Code Division Multiple Access
Replacement for
FDMA, TDMA (GSM)
CDMA-2000
Network generation served
2G-3G
3G
Frequency bands
1.25Mhz
5Mhz

 

CDMA vs. WCDMA- How these two compare

Tech family

As you will find in the history portion of the review below, CDMA is a relatively older technology developed to sustain GSM based 2G networks. This is unlike WCMDA specifically mandated to work with the 3G UMTS network. Since they are part of two different cellular networking standards, the two standards feature different data rates, with varying speed capabilities. For instance, WCDMA allows faster data rates on 3G networks unavailable on the older CDMA 2G networks: making WCDMA much better.

Implementation

The fundamental difference between these two standards is based on the frequency bands each of these radio access technologies utilizes . CDMA and WCDMA vary greatly with respect to the channels on which ether technology is equipped. For instance, CDMA is made for 1.25MHz channels while WCDMA functions of on. 5MHz channels. The wider channels on WCDMA allow users access to better data rates, thanks to the improvements on spectral efficiency, and spreading.

Performance

It is difficult to put in perspective performance on radio access technologies. WCDMA empowered devices are more equipped for faster data rates, with better security and overall better performance compared to CDMA. With this in mind, WCMA offers greater operation over the 5MHz channels compared to the older CDMA version.

CDMA vs. WCDMA- Comparison review

CDMA

CDMA vs WCDMA

The Code Division Multiplexing Access is a cellular communications tech used to maximize transmissions over radio spectrum. This technology developed to serve 2G and 3G networks is a form of DSSS technology, the main scheme used to develop CDMA. Notably, Frequency allocation on CDMA allows this tech to operate on two modes: FDD and TDD.

CDMA features more advantages compared to older Multiple Access Technologies including FDMA and TDMA. With it, many users coexist on a single bandwidth without issue. Techniques including direct sequence and Frequency hopping are utilized on CDMA.

Many contingencies are set up to ensure multiple users could access these 2G connections concurrently without interferences. In fact, this tech allows many users to coexist simultaneously on a single bandwidth. Spreading for example on CDMA is enabled using spreading codes. These are designated sequences that allow users to send pieces of data over a number of frequencies. Spreading codes are utilized within this technique to carry information bearing signals, after which the signal is recovered when it reaches its destinations. For this reason, CDMA is considered a spread spectrum technology used on ultra high frequency phone systems.

Since its deployment as CDMA on 2G communications networks, this standard has evolved to accommodate even faster data rates and overall better performance. Said evolution is marked by a gradual transition all the way to CDMA-2000 to the development of more reliable multiple access technology: WCDMA.

Some of the benefits that accompanied the use of CDMA as the primary 2G radio access tech include better security and overall improved network performance for many users. Other the major changes which occurred after the inclusion of CDMA on cellular networks are the improvements in handoff and capacity. With these said networks became considerably reliable and generally increased capacity. Speaking of capacity, various factors within CDMA based networks influence this features including the frequency reuse efficiency, signal to noise ratio, and much more. Moreover, the model features soft capacity where codes are used to separate users on each frequency.

WCDMA

cdma

Wideband Code Division Multiplexing Access is among 3G’s widely used air interface, prior to the development of the more reliable HSDPA technology.  While WCDMA is based off of CDMA technology, it features wider bands, occupying 5MHz channels. These are useful for transmitting both voice and data over said 5MHz channels. Initially, this standard allowed data rates of 384kbps.

This technology is founded on 2G;s CDMA technology: specifically CDMA2000. WCDMA supports the more complex UMTS cellular technology deployed on 3G networks. With it, UMTS driven systems easily maintain and develop different documents and specs. In fact, the switch to WCDMA as the primary air interface for UMTS allowed 3G UMTS networks improvements in speed, and overall network operation. While not the fasters 3G networking development, WCDMA ranks well above other technologies as among the most valuable technological additions made by the 3GPP initiative.

Other enhancements incorporated onto the WCDMA design include transmission diversity with an adaptive antenna operation and included support for advanced receiver structures. With WCDMA access standards, this tech allows for packet data and radio switched data. Since the WCDMA tech is meant to increase signal bandwidths, it features greater capacity, and performance compared to the original CDMA standards.

Some of the advantages WCMDA brought to 3G networking include higher data rates on a more dynamic bandwidth adaptation, improved spectral efficiency and much more.

Conclusion

CDMA represents a huge milestone for cellular communications tech and has led to many developments within the telecommunications’ industry in terms of radio access technologies. With the information above, users should not only have an in-depth understanding what this cellular tech had to offer, but also have the capacity to differentiate CDMA from its successor WCDMA.

Verdict, So which one is better: CDMA or WCDMA?

All things considered, WCDMA functions better as an access technology compared to CDMA. This is understandable considering WCDMA is an improvement on CDMA technology.

Frequently asked questions

What is mean by WCDMA?

This is a 3G standard based on the CDMA tech from 2G networking that offers wider channels which function better to transmit data and at faster rates.

Is CDMA the same as Wcdma?

While WCDMA is based on CDMA technologies, these standards are not the same thing.

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