| Summary: | 碩士 === 國立成功大學 === 電腦與通信工程研究所 === 98 === Ultra-Wideband (UWB) impulse radio signals apply very short duration and are able to resolve multipath due to their fine time-resolution capability. To take full advantage of the available signal energy, a Rake receiver with high hardware complexity is required. To remedy this difficulty, an improved scheme called the transmitted reference (TR) systems has been proposed in literature.
TR systems do not require the complex task of channel estimation, thus their receiver structures are greatly simplified. However, the low-complexity on the detection of TR systems is achieved with the cost of 50% energy/bandwidth to transmit the reference signal. Moreover, the reference template in the TR systems also produces an additional noise-time-noise term. How to reduce such disadvantage of UWB TR systems has attracted much research effort nowadays.
We propose several improved TR systems in this thesis, such as: (1) The BTR+A2TR system, which cancels out all of the inter-pulse interference(IPI); (2) The Doublet-shifted Averaged Transmitted-Reference (DsATR) system, which contains three data bits in each frame and average the received signal in the receiver to decrease noise; (3) the N-bit Differential Transmitted-Reference (NDTR) system, which contains N-bit data in each frame of the transmitted signal; (4) The Averaged N-bit Differential Transmitted-Reference (ANDTR), which combines the high data rate and a low noisy template; (5) The ANDTR+BTR system, which not only contains all the advantages of the ANDTR system, but also adds the ability to cancel out some of the IPI; (6) The A2NDTR+BTR system, which is able to cancel all of the IPI.
The systems mentioned above are designed for a single user. The multiple access performance of ATR、BTR+ATR and BTR+A2TR systems are simulated and compared in this paper.
|
|---|
