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A scalable video delivery transmission framework over MIMO OFDM wireless channels by combining power allocation and antenna selection scheme has been proposed. The framework consisting of independently decodable layers (3D ESCOT), UEP channel coding structure, and antenna selection scheme provide more system error resilience even during deep fading period in wireless channels. A new algorithm is proposed...
This paper exploits the use of location information of wireless terminals to improve the performance of a beamforming system and support multiple access. Based on a system providing real-time 3D coordinate information of all terminals in the environment, a novel feedback-free multi-user scheduler is proposed. It chooses a set of angularly separated wireless terminals for simultaneous transmission...
Orthogonal frequency division multiple (OFDM) system with two-level spreading is an effective approach to suppress interference in wireless communication. However, in this system, the orthogonality of its spreading code can be destroyed by multipath fading. In this paper, we propose a novel resource allocation scheme that joints conventional two-level spreading OFDM and smart antenna so as to use...
We present high data rate wideband transceiver design and experimental evaluation for 3.62 Gbps wireless transmission systems in this paper. The present system provides high definition moving picture and contents in a real-time wireless environment at home, offices or class rooms of universities. Also, the present platform provides a test platform for the Giga level high throughput wireless communication...
This paper deals with a new multi-user linear precoding technique for downlink of distributed MIMO OFDM systems. We consider a distributed broadband wireless system where some base stations are transparently linked by optical fiber to a central unit. We further assume that the user terminals are equipped with an antenna array and the distributed base stations equipped with either single or an antenna...
In this paper, two heuristic resource allocation algorithms are proposed for downlink of multiuser orthogonal frequency division multiplexing (OFDM) distributed antenna system (DAS). The objectives are to maximize total system rate under fairness among users constraint. Unlike the existing algorithms that allocate each subcarrier to only one user within the system, the proposed algorithms are based...
There are a few core technologies to enable high-performance 4th generation (4G) broadband wireless communication system. A multiple input multiple output (MIMO) provides high-rate transmission through expended channels by multiple array antennas in both sender and receiver side. Also orthogonal frequency division multiplexing (OFDM) is well-known as the most appropriate technique for high data rate...
This paper examines a WiMedia UWB product by performing comprehensive throughput measurements and a path loss and link budget analysis based on the measured data in office and residential environments. The UWB product conforms to WiMedia's multi-band orthogonal frequency division multiplexing specification. The link budget analysis results together with detailed throughput versus range measurements...
In this paper, we consider channel estimation for the reception of OFDM signal in spatially correlated multi-antenna environments. To improve the accuracy of channel estimation, we exploit the characteristics in three dimensions; time, frequency and spatial domain. The channel information is first estimated from pilot signal by means of a conventional least squared method in the frequency domain....
Multicarrier and multiple transmit/receive antenna have become two key technologies underpinning most of the current development and research efforts towards ubiquitous high-throughput wireless communications. Both techniques can be used to increase the link throughput and/or to improve its robustness against channel fading and noise. This paper presents a unified bit error rate analysis for a particular...
An efficient and flexible air interface is the necessary condition for enabling high data rates next generation wireless systems. A practical answer to this need consists in exploiting channel state information at the transmitter for an adaptive and efficient use of the available radio link resources. This paper contributes with a novel strategy for the allocation of the sub-carrier transmit power...
A simple MIMO-OFDM wireless communication system is constructed based on the analysis of the technical principles and the system models of the MIMO technology and the OFDM technology. The system combines the MIMO system and the OFDM system together, space-time coding is done in the transmitter firstly, the signal is launched after OFDM modulated, and the process of the receiver is the inverse process...
For a single user with multiple receive antennas, co-antenna interference can be the dominant source of impairment in a Spatial Multiplex Orthogonal Frequency Division Multiple Access (SM-OFDMA) system, particularly when correlation exists between spatial sub-channels. By exploiting knowledge of the channel response and combining it with Dynamic Sub- Carrier Allocation (DSA), the algorithm proposed...
Coded multi-antenna and multi-carrier techniques combined together with link resources adaptation algorithms are the key technologies toward efficient high-data-rate communications over wireless fading channels. The practicability of this concept, however, requires that the transmitter can perform accurate and simple evaluation of the actual link performance. This paper contributes with a novel method...
MIMO-OFDM system has the same defect as OFDM system, that is it has a high PAPR, which means when the signal pass through the non-linear power amplifier and other devices, it would require the amplifier has a wide dynamic range, otherwise, it would have a non-linear distortion, the generated harmonics will cause interferences among the sub-channels, finally it leads the signal distorted in interactive...
Recently, Li, Hwu and Ratazzi have proposed a physical-layer security design to guarantee low probability of interception (LPI) for MIMO systems without relying on upper layer data encryption. The proposed scheme utilizes antenna array redundancy to deliberately randomize the transmitted signals to prevent eavesdropping. Motivated by their idea, in this paper we design a physical-layer transmission...
In this paper, a detection algorithm with parallel partial candidate-search algorithm is presented. Two fully independent partial search processes are simultaneously employed for two groups of transmit antennas based on QR and QL decompositions of the channel matrix. Proposed QRD- QLD detection algorithm is compared with well-known QRD-M scheme adopted for several emerging wireless standards. Latency...
Multiple antenna wireless technology and orthogonal frequency division multiplexing (OFDM) have the potential to enable high data rate wireless applications. While the multiple-input multiple-output (MIMO) wireless techniques exploit spatial domain for improving the quantity and reliability of the data transmitted, OFDM converts the frequency-selective broadband channel into a bank of narrow band...
Multiantenna wireless systems have been well studied in achieving high data rates. In this paper, we improve a subspace-based blind channel estimation technique for multi- input multi-output (MIMO) orthogonal frequency-division multiplexing (OFDM) approach based on tracking the subspace recursively. The recursive subspace algorithm has a computational complexity of O(J2) , where the J is the input...
This paper presents an analytical model for symbol error rate (SER) calculation of a polarization receive diversity system with equal gain combining (EGC) of the received signals. Ricean fading statistic characterizing wireless communication channel is assumed. Pade rational approximation to the moment generating function (MGF) of the output SNR (signal-to-noise ratio) is used in the case of EGC....
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