Research On Key Technologies Of Resource Allocation In Multi-antenna Telecommunication Systems

With the development of wireless multimedia, wireless network and mobile computing equipment, recently the wideband mobile communication systems become the hot research technique. Several new techniques on wireless communication and wireless access field are brought forward, which accelerate the development of telecommunication. During all these wireless techniques, Multi-input Multi-output (MIMO) is one of the most representitive techniques. MIMO technique has big advantage over other techniques which can enhance the diversity gain and system capacity to meet the high-speed requirements of different users. MIMO has become an effective technique with its outstanding advantages. From WLAN to WiMAX and Flash-OFDM, From LTE to B3G and even to UWB technique and LTE-advanced, MIMO is the symbol in the new generation of wireless communication. So researches on MIMO techniques have both theoretical values and practical values.Firstly, the paper introduces the principle and architecture of high-speed MIMO mobile systems. Moreover, this paper presents the key techniques which include space-time coding, power allocation, sub-carrier allocation, user selection, codebook design and limited feedback control, etc.The technique of optimal resource allocation in transmitter part belongs to the adaptive techniques in link level. In this technique we can adjust the parameter of resource allocation according to channel state information (CSI) in order to raise the availability of wireless resource in MIMO system. Adaptive resource allocation adopts the optimization method and improves the system performance to meet different rate requirements compared to the static resource allocation method. Based on it, this paper proposes a new optimal multi-user power scheduling algorithm. The proposed algorithm minimizes the transmit power of multi-user MIMO-OFDM system while meet each user's rate requirement. Based on the channel state information, the proposed algorithm combines power allocation and user scheduling. After user selection and sub-carrier allocation, power allocation is carried out among the selected users.To solve the problem that the dirty-paper coding based iterative water-filling algorithm to maximize weighted sum- rate has high complexity in multi-user MIMO system, a low complexity zero-forcing dirty-paper coding based multi-user resource scheduling algorithm is proposed. Under the transmit power constraint, the proposed algorithm combines power allocation and user scheduling. Users are selected in sequence based on the user-selection parameters which are constructed using the channel state information. The proposed algorithm only needs finite repetitions, and can drop off those users with poor channel quality through the user-rejection criteria. Therefore the complexity is reduced.The performance of vector quantization with codebook comprised of multiple sets of orthogonal vectors in SDMA systems with limited feedback is analyzed in this paper. Mathematical expressions for the channel direction information (CDI) vector quantization error distribution. Then the downlink SINR distribution of orthogonal beam-forming SDMA systems is derived. In addition, numerical results show that the analytical deduction is coincident with the actual facts. Base on the distribution, a feedback-control scheme for SDMA systems is proposed. The scheme sets thresholds both for quantization error and channel gain to implement the precise control of feedback. A new codebook-design algorithm for multi-antenna SDMA system is also proposed in this paper. The algorithm modifies the general Lloyd algorithm. A new codebook consists a set of orthogonal sub-codebook is constructed using the modified Lloyd algorithm for SDMA system. Simulation results show that the proposed algorithm can reduce the vector quantization error of CSI, and compared with the existing codebook, the new codebook can get higher sum-rate of SDMA system with limited feedback.The paper does deep research about the resource scheduling in high-speed MIMO system according to the important techniques in 3GPP LTE conference, and forms some papers and patents. We need do more research about the techniques of mobile communication and application in real life, especially on the techniques of multi-cell MIMO system.