Adaptive Differential Space-Time-Spreading-Assisted Turbo-Detected Sphere Packing Modulation

In this contribution a novel adaptive differential space-time spreading assisted turbo detected sphere packing modulation scheme is proposed for improving the achievable throughput of code division multiple access (CDMA) systems. The scheme is capable of accommodating the channel signal-to-noise ratio (SNR) variation of wireless systems by adapting the system parameters. Explicitly, an adaptive transmission scheme constituted by a novel reconfigurable four transmit antenna aided arrangement using a variable spreading factor based differential space-time spreading scheme, as well as variable code rate recursive systematic convolutional codes is introduced. Our results demonstrate that significant effective throughput improvement can be achieved while maintaining a target bit-error-ratio of 10^-4. Explicitly, when assuming an ideal Nyquist filter having a zero excess bandwidth, the system´s effective throughput varies from 0.25 bits/sec/Hz to 16 bits/sec/Hz.