A new block coded modulation scheme with inter-level memory is proposed. The proposed code construction is based on the use of single parity check codes to concatenate a set of coded blocks. Simulation results show that the proposed scheme can achieve considerable coding gains while the decoding complexity is not too large.

A prototype modem with unequal error protection (UEP) capability was developed using multiple block coded modulation (MBCM). Benefited from its unique structure, MBCM can be used to provide UEP straightforward. We propose a new method to increase the robustness of the carrier recovery process by taking advantage of the MBCM code structure. We also use a frame format to facilitate the synchronization operation. This modem was developed in preparation for the mobile satellite communication experiments using the Engineering Test Satellite of VIII-type (ETS-VIII). In addition of MBCM, some other types of modulation schemes have been implemented in the same modem to enable a range of communication experiments to be performed. The modem can operate at variable data rates. The results of laboratory measurements agreed well with computer simulation results. Typical link budgets based on the parameters of ETS-VIII are also presented.

Unequal error protection (UEP) is a very promising coding technique for satellite broadcasting, as it gradually reduces the transmission rate. From the viewpoint of bandwidth efficiency, UEP should be achieved in the context of multilevel coded modulation. However, the conventional mapping between encoded bits and modulation signals, usually realized for multilevel block modulation codes and multistage decoding, is not very compatible with UEP coding because of the large number of resulting nearest neighbor codewords. In this paper, new coded modulation schemes for UEP based on unconventional partitioning are proposed. A linear operation referred to as interlevel combination is introduced. This operation generalizes previous partitioning proposed for UEP applications and provides additional flexibility with respect to UEP capabilities. The error performance of the proposed codes are evaluated both by computer simulations and a theoretical analysis. The obtained results show that the proposed codes achieve good tradeoff between the proportion and the error performance of each error protection level.

As the demand for communications via satellite is rapidly increasing, techniques that produce large traffic capacity are becoming more and more appreciated. We present a class of block coded modulation (BCM) and multiple block coded modulation (MBCM) schemes in this paper. While the BCM scheme is directly derived from our previous work, the MBCM schemes are newly developed using a technique of multiple symbol transmission via a single trellis branch. This class of BCM and MBCM schemes is both power and bandwidth efficient. They also have an advantage in holding both a trellis and a block structure. Code structures, decoding trellises and the corresponding branch variables of these BCM and MBCM schemes are all derived. Their applications to satellite communications are discussed. Computer simulations are performed to verify coding gain performance.