I. Field of Invention
The invention generally relates to wireless communication and, more particularly to an orthogonal frequency division multiplexing scheme to modulate digital data into audible tones for wireless communication and authentication.
II. Description of the Related Art
Advances in communication technology have made it easier and faster to share and/or transfer information. High volumes of data can be communicated through data transmission systems such as a local or wide area network (for example, the Internet), a terrestrial communication system or a satellite communication system. These systems require complicated hardware and/or software and are designed for high data rates and/or long transmission ranges.
For transfers of data over short distances, such as between a personal computer and personal data assistants (PDAs), the systems above may be an inconvenient communication medium for users because of the complexity, delay and often the cost involved in accessing the systems. Accordingly, various communication systems have been developed using communication medium such as radio frequency (RF) or Infrared (IR) to transmit data. However, these systems also require specialized communication hardware, which can often be expensive and/or impractical to implement. Non-wireless connections can also be used to transfer data. However, to use non-wireless types of connections, users must physically have as well as carry wires or cables and make the physical connections for communication. This can be burdensome and inconvenient to users.
Moreover, with the increase in electronic commerce, the opportunities for fraudulent activity have also increased. Misappropriated identity in the hands of wrongdoers may cause damage to innocent individuals. In the worst case scenarios, a wrongdoer may actually purloin a party's identity in order to exploit the creditworthiness and financial accounts of an individual.
In order to prevent unauthorized persons from intercepting private information, various security and encryption schemes have been developed so that private information transmitted between parties is concealed. However, concealment of private information is only one aspect of the security needed to achieve a high level of consumer confidence in electronic commerce transactions. Another aspect is authentication.
Accordingly, electronic authentication of an individual may currently be performed by authentication through knowledge, such as a password, secure identification or a personal identification number (PIN); authentication through portable objects, such as a credit card, or a proximity card; and/or authentication through personal characteristics (biometrics), such as fingerprint, DNA, or a signature.
With current reliance on electronic security measures, it is not uncommon for an individual to carry multiple authentication objects or be forced to remember multiple passwords. Authentication through knowledge can thus be problematic for individuals who are forced to remember multiple passwords or PINs. Accordingly, such information may be written down on objects. However, writing down such information leaves an individual vulnerable to the theft of passwords, PIN codes, or even the object itself. Accordingly, there may still be a burden and/or expense to conceal the object from others.
Therefore, there is need for a less complex, yet user-friendly, inexpensive and/or efficient way to share and/or transfer information.