O-F-D-M

The best way to learn about OFDM basic facts is to look at a good OFDM video tutorial. However, in the interim, this short article will teach you some information about basic OFDM and how it is used.
OFDM is an acronym that stands for Orthogonal Frequency-Division Multiplexing - it is a way to transfer data at high speeds using broadband multicarrier modulation methods.

The rate at which data is transferred has a direct effect on how good the quality of the transmission. Line noise is a frequent problem with fast data transmissions.  Transmitting data slowly results in less interference and line noise. A multicarrier modulation method, as used by OFDM, allows for many small pieces of data to be sent and then later combined to arrive as a single unit.

With OFDM the data is split into up to 52 substreams, and later made into a single mutiplexed stream. This method allows data to be sent at a slower rate, but in a very fast time frame.

The concept of OFDM is not actually new - the possibility of using such technology has been known for around the last 50 years. The method was originally referred to as multicarrier modulation, but needless to say, the technique would have been extremely hard if not impossible to implement as the hardware for such technology was simply not available at the time. For that reason, it has basically been a concept that remained a possible interesting reality for the future until now - when the latest computer technology makes it possible.

In the last few years, interest in OFDM has greatly increased along with the demand for new wireless technology and high speed data transfers. OFDM is a perhaps the most efficient method of transferring data that has been discovered up till today as it alleviates the problem of multipath broadcast that usually results in immense data errors and loss of signal in the microwave and UHF wave spectrum.

The main advantage of using OFDM is the increase in bandwidth efficiency it creates. This means it is possible to send large amounts of data without interference and noise. Bandwidth efficiency is measured at bits per second per Hertz, which is written as bps/Hz.

Wireless high-frequency data transfer usually has multipath issues, but these are eliminated with OFDM. Very short-wavelength signals can travel easily in a straight line of sight from the transmitting antenna to the receiving antenna, but this is not usually the reality when transmitting data, as buildings, trees, hills, water reservoirs and people will reflect some of the signal. This results in a copy of the original signal, and that is also received by the receiving antenna. This can cause data cancellations or other incongruities. OFDM technology splits the data up, and it is transmitted in small pieces. This means data can be sent with less line noise, and the likelihood of problems with the transmitted data is decreased immensely.