Constellation Shaping and Peak-to-Average Power Ratio Reduction Algorithms for Wireless Communications

• Main Author: Khoo, Boon Kien
• Published: University of Newcastle upon Tyne 2005
• Subjects: 621.382
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484815

Wireless communication technologies have undergone an explosive growth over the last two decades. High reliable transmission, high data rate, bandwidth and power-efficient communications are however major concerns for future wireless application designs. In the first part of this thesis, a bandwidth as well as power-efficient coded modulation system is proposed. Bit-interleaved coded modulation (BICM) system is a well-known bandwidth-efficient coded modulation scheme that concatenates channel codi!1g, interleaver and modulation block. The concatenation makes the BICM system similar to a serial concatenated convolutional code, and thus suggests that, in the receiver, the demodulation block and decoder can operate in an iterative manner resulting in turbo-like performance. Such system, known as bit-interleaved coded modulation with iterative decoding (BICM-ID), is well suited to additive white Gaussian noise channel. In the proposed technique, the BICM-ID system is modified by inserting a single short-length binary shaping block code for constellation shaping purpose. The corresponding receiver structure is then made up of four main blocks exchanging extrinsic information. By combining constellation shaping and BICM-ID system, the average transmitted power can be reduced and thus resulting bandwidth as well as power-efficient coded modulation system. In the second part of the thesis, high peak-to-average power ratio· (PAPR) of orthogonal-frequency division multiplexing (OFDM) for high data rate communication systems is focused. To date, there are a number of existing techniques for PAPR reduction. Among these techniques, selected mapping (SLM) technique is one of the well-known method to overcome the PAPR problem. However, the implementation of SLM technique required side information transmission. To this end, a simple SLM technique for PAPR reduction in OFDM that does not require the explicit transmission of side information is proposed.