The generator matrix and the weight distribution of a new$[52, 18, 16]$linear binary block code are presented. The minimum distance of the known$[52, 18, 15]$linear binary block code is improved, achieving the upper bound on minimum distance for length 52 and dimension 18.

Software Defined Radios (SDRs) offer a programmable and dynamically reconfigurable method of reusing hardware to implement the physical layer processing of multiple communications systems. An SDR can dynamically change protocols and update communications systems over the air as a service provider allows. In this paper we present techniques for implementing communications systems in software. We describe briefly the SB3011 platform and programming environment. We then present a number of useful techniques that can be used to implement working systems. We further describe in which systems these techniques are implemented.

A new$[47,15,16]$linear binary block code and its weight spectrum is presented. The code is better than the previously known$[47,15,15]$code and it reaches the upper bound on code distance for the codeword length$47$and dimension$15$.

This article presents a method to find convolutional codes with good translation properties by modifying the generator matrix of existing codes and using a bit modifier. Applying the method causes no loss in the error correcting performance and only slight modifications to the architecture of existing encoders and decoders. The new codes' maximal runs of both zeros and ones are constrained. It is shown that some of the new line codes are DC-free.

A.J. McAuley (IEEE/ACM Trans. Networking, vol.2, p.16-22, 1994) proposed a new family of error detection codes called weighted sum codes. In the present paper it is noted, that these codes are equivalent to lengthened Reed Solomon codes, resp. shortened version of lengthened Reed Solomon codes over GF(2/sup h/2/). It is also shown, that it is possible to use these codes for error correction of one error in the code word over GF(2/sup h/2/).>