We investigate the potential of restricted PHY co- operation for the downlink of 4G networks. The cooperation is restricted to a cluster of eNodeBs. We distinguish between low and high mobility users, and propose two appropriate cooperation methods. The goal is to guarantee high user rates even on cell edges. We present a simulation study to analyze the spectral efficiency achieved by cooperation methods for urban micro cells. To investigate their influence on coordinated multipoint (CoMP), we consider different frequency allocation strategies and different sector orientations in a cell. In addition, we compare CoMP transmission to Multiuser MIMO and investigate how cooperation can improve power allocation. Based on the results, we provide important insights into future cell planing aspects.

Ultra wideband (UWB) communication is a very promising candidate for the use in wireless body area networks (BAN). The high UWB peak data rate allows for medium average data rates in combination with a very low duty cycle, which is the key for a very low power consumption. Devices in a wireless BAN require low complexity. Hence, mainly non-coherent receivers such as energy detector and transmitted-reference receiver are suited. In this paper, the symbol-wise maximum-likelihood (ML) detectors for pulse position modulation (PPM) and transmitted reference pulse amplitude modulation (TR PAM) are derived assuming partial channel state information (CSI) at the receiver. Additionally, also the ML detectors for a combination of PPM and TR PAM are presented. The performance of the derived receiver structures is evaluated using a novel BAN channel model not distinguishing line-of-sight and non line-of-sight situations. This simple channel model is based on 1100 channel measurements in the frequency range between 2 and 8 GHz, which were measured in an anechoic chamber. Using the BAN channel model, performance of the derived receiver structures is evaluated showing that the knowledge of the average power delay profile (APDP) at the receiver improves performance substantially. Requiring only slightly more complexity such receivers are a well suited alternative to non-coherent receivers for the use in a BAN.

A wireless body area network with an average throughput of 500 kbps is considered based on ultra-wideband (UWB) pulse position modulation. For a long battery autonomy ultra low power consumption is essential. A FCC compliant ultra low power UWB communication system was presented. By means of a 1% duty cycle at 50 Mbps peak data rate, the power consumption of the system is estimated below 1 mW. To increase inter-symbol interference (ISI) robustness as well as for synchronization, a simple post-detection maximum-likelihood sequence estimator (MLSE) has been presented. In this work, we extend this MLSE approach to over-sampled energy detectors and non-ideal integration windows. Furthermore, we present optimal MLSE metrics based on partial channel state information as a performance benchmark.

Non-coherent receivers such as transmitted reference receivers recently attracted much interest due to the complexity of coherent ultra wideband (UWB) receivers. In this paper, we investigate the impact of channel state information (CSI) on UWB transmitted reference (TR) maximum likelihood (ML) receivers in the presence of a UWB co-channel interferer (CCI). TR ML receivers are derived assuming the following kinds of channel state information: full CSI, knowledge of the magnitude of the channel impulse response, and no CSI. We compare the performance of these ML estimators with and without CCI by means of bit error rate simulations