A Design And Optimization Of An Array Receiving Scheme For Wireless Wideband OFDM Signals

The improvement of wireless network performance has always been the focus of attention from the academia and the industry. People of twenty-first century have come into the Information Age, whose lifestyle unprecedentedly relies on information exchange and data transmission. With wireless terminals booming in variety and quantity, wireless data transmission volume grows with each passing day. The increment speed of data production and transmission has far surpassed the development speed of wireless communication technique, which greatly challenges the data transmission rate of wireless communication.The most direct and effective means to improve the wireless transmission rate is to expand the channel bandwidth. The development history of IEEE 802.11 protocol family clearly shows a tendency of widening channel bandwidth along with the improving data rate. The measurement of wireless channel bandwidth has gone up form MHz to GHz and sub-THz. The tendency will not stop. The hardware realization complexity of traditional wireless transceiver design is too high to support wideband wireless communication. Limited to the manufacture level of filter and ADC, the cost and complexity of traditional receiver for multiple GHz bandwidth is extremely high.Aiming to solve the challenge of wideband and high-speed wireless communication, we design an array receiving scheme, which we call STTGR in the next context, for wireless wideband OFDM signal, and further do some optimization work on it. STTGR is a combination work of software and hardware. The key point is to use an array of narrow-band devices to receive a wideband signal. An array of fixed and limited bandwidth devices composes the front end of STTGR. Post processing algorithms are designed to stitch together the narrow-band data received by devices in the array to realize the receiving of the wideband signal.Firstly, we design an array receiving scheme STTGR based on OFDM, whose operation bandwidth is extensible. STTGR breaks through the operation bandwidth limitation of traditional wireless receiver, providing innovative thinking for new generation wireless communication. The basic idea of STTGR is to arrange many narrowband radio devices as a receiving array. Each narrowband device process a sub-signal on a sub-band of the wideband OFDM signal. Then software algorithms are applied to synthesize and process the results of narrowband devices to recover the wideband OFDM signal. Detailed design, theoretical derivation and simulation results are presented in the third chapter.Secondly, we perform some optimization work on STTGR. In spired by the idea of multiuser diversity, the BER and power efficiency of STTGR can be optimized by taking devices in the receiving array as multiple users. Exploring the fading characteristics of wireless channel and multiuser diversity to adjust the subcarrier allocation, the BER can be minimized or the power efficiency maximized. According to the different optimization objects, we design four subcarrier allocation algorithms. Two algorithms serves for the object of minimizing BER, a subcarriers allocation algorithm based on greedy strategy and an algorithm to allocate subcarriers in turn. The other two serves for the object of maximizing the power efficiency, a subcarriers allocation algorithm based on Genetic Algorithm and a subcarriers allocation algorithm base on Particle Swarm Optimization. Detailed optimization problem description, algorithms design, and simulation results are presented in the fourth chapter.The main character of STTGR is the receiving bandwidth if extensible and the size of the array is scalable. The ability of sustainable development are preferable by the future generation wireless communication. The research results of this dissertation are expected to make breakthroughs in the field of wireless communication and to provide original technique support for future generation wireless communication. The work of this dissertation possesses important theory significance, practical value and broad application prospects.