In conventional communication systems, error correction is carried out at the physical layer while data security is performed performed at an upper layer. As a result, these steps are done as separate steps. As opposed to this conventional system, we present a scheme that combines error correction and data security as one unit so that both encryption and encoding could be carried out at the physical layer. Hence, in this paper, we present an Error Correction Based Cipher (ECBC) that combines error correction and encryption/decryption in a single step. Encrypting and encoding or decoding and decrypting in a single step will lead to a faster and more efficient implementation. One of the challenges of using previous joint schemes in a communications channel is that there is a tradeoff between data reliability and security. However in ECBC, there is no trade off between reliability and security. Errors introduced at the transmitter for randomization are removed at the receiver. Hence ECBC can utilize its full capacity to correct channel errors. We show the result of randomization test on ECBC and its security against conventional attacks. We also present the result of the FPGA implementation of the ECBC encryption.

In wireless ad-hoc networks, a major challenge is how to provide robust and efficient communication. To achieve this goal, cooperative communication and network coding have been proven to be effective. In the literature, most existing studies focus on the performance of the two schemes separately. In our study, we will investigate the performance of system that combines them tightly together. In particular, we will propose a unified two-way traffic model that can characterize the features of both of them. Based on this model, we develop a new cooperative network coding scheme to further improve the system throughput. Both decode-and-forward and amplify-and-forward techniques are discussed for the two-way traffic model. Numerical results show that the new scheme can significantly improve the performance over traditional schemes.

Codes are developed for detecting unidirectional errors in t bytes simultaneously (t-UBED) while also providing all unidirectional error detection (AUED). These classes of codes differ from purely all unidirectional error detecting codes in that the errors in one byte may be of the form 1 to 0, while in another byte they may be of the form 0 to 1. The codes utilize 2 B for parity check information. As an example, a code providing 3-UBED+AUED protection for up to 12 information bytes of 8 b each can be constructed.>

The authors focus on collision detection for planning collision-free motion of two robot arms in a common workspace. A collision-free motion is obtained by detecting collisions along the straight-line trajectories of the robots using a sphere model for the wrists and then replanning the paths and/or trajectories of one or both of the robots to avoid collisions. A novel approach to collision detection is presented and a discussion on collision avoidance is given.>

Error correcting codes, such as Hamming codes, have been used successfully to correct errors arising from failures in computer memories. Failure of a chip or card can cause errors which exceed the capabilities of these codes. We construct codes which detect any byte error and correct such errors if they are single random errors. A subclass of the codes developed is shown to have the additional capability of detecting double errors. These codes are intended for use when data are packaged on a byte per chip or a byte per card basis. The codes require fewer check bits than any previously known to the authors except when the byte length or number of bytes is small.

Single error correcting-double error detecting (SEC-DED) codes have been successfully used in computer memories for reliability. In the present-day technology of very large scale integration storage arrays bit error correction as well as byte error detection/byte error correction become extremely important. We devise here classes of cyclic codes with generator of the form (xb -1) p(x) for some suitable irreducible polynomial p(x) which provide 1) single byte error correction (SBEC), and 2) single error correction, double error detection, and byte error detection (SEC-DED-BED) codes. The codes have high information rate and are easy to implement. This general class of codes combines elegantly the results of several researchers and in some cases extends their results.