下行的

Adjustments of Second-hand housing policy reduce the deal cost, boosting buyers' expectations; In addition, such change may increase the liquidity of housing, which will speed up investment in new housing and shops. However, the price continue to drop, especially when the new year is coming, more shop investors keep waiting and seeing due to the financial crisis, macro news. Basing on the demand point of view, some demand for living improvement delay the bargain, so did demand for investment due to bad profit-making. As a result, the demand is difficult to start up, while the supply funds is not sufficient, therefore such commercial real estate enterprises will be out of the market due to their inability to meet the finance crisis. Under competitive pressures, the developers will pay more attention to products quality and products differentiation with a view to compete in the market to get a dominant position.

二手房政策的调整降低了购房者的购房成本，刺激了购房期望；另外，二手房政策的改变可能会增加房源的流动性，这样也会加速新房的销售，商铺投资逐渐活跃，但价格表现却成下行趋势，尤其是年关临近，在金融危机面前，商铺投资者多持币观望，从需求者的角度讲，部分改善型需求和投资型需求的购买行为将向后推迟，炒房者将因投机能力下降而不同程度地退出市场，另外，需求难以启动，供给方资金链紧张，部分自有资金不充裕的商业地产企业将面临因无力融资而退出市场的风险，企业因竞争压力大，将更加注重开发产品的品质，提供差异化的产品，以期在市场竞争中占得优势地位。

In view of crosswell and 3D VSP layout, we use high resolution Radon transform based on Cauchy distribution to perform Radon transform for hole data. In this process, we study discrete dip overlay operator, improve damping factor that affects Radon energy convergence in order to let Radon energy converge, 6 resolve leggy in Radon data, and decouple smoothing effect among each energy group, we use Cauchy distribution to regularize data, let energy focus on one point, and improve Radon resolution. All these work well in wavefield separation. Finally, by inversion results and model trial, we verify the feasibility and stability of this method.

在Radon变换原理分析基础上，采用基于柯西分布的高分辨率线性Radon变换对井孔数据进行Radon变换，其间通过对离散倾角叠加算子求取的研究，及对影响Radon能量收敛的重要参数阻尼因子算法的改进，使数据在Radon域以能量团的形式呈现，得到很好的收敛效果，基本解决了Radon域数据的一定程度的拖尾现象，消除了各能量团之间的平滑效应，采用柯西分布来规则化数据，提高了Radon域的分辨率，Radon域能量也收敛到一个点上，有利于上下行波或纵横波波场分离。

In view of crosswell and 3D VSP layout, we use high resolution Radon transform based on Cauchy distribution to perform Radon transform for hole data. In this process, we study discrete dip overlay operator, improve damping factor that affects Radon energy convergence in order to let Radon energy converge, 6 resolve leggy in Radon data, and decouple smoothing effect among each energy group, we use Cauchy distribution to regularize data, let energy focus on one point, and improve Radon resolution. All these work well in wavefield separation.

在Radon变换原理分析基础上，采用基于柯西分布的高分辨率线性Radon变换对井孔数据进行Radon变换，其间通过对离散倾角叠加算子求取的研究，及对影响Radon能量收敛的重要参数阻尼因子算法的改进，使数据在Radon域以能量团的形式呈现，得到很好的收敛效果，基本解决了Radon域数据的一定程度的拖尾现象，消除了各能量团之间的平滑效应，采用柯西分布来规则化数据，提高了Radon域的分辨率，Radon域能量也收敛到一个点上，有利于上下行波或纵横波波场分离。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

On account of this, a multi-carrier solution is applied in our discussion to get a reasonable frequency allocation scheme for the hybrid network. The conventional cellular links and the signaling links use the main carrier, while the direct-connected links are on the secondary carrier. Thus the interference between the two kinds of links is restricted.

由于传统上下行链路以及对等链路的共存会引入相当大的互干扰，本文采用多载波的方案为混合网络设计了合理的频率分配，传统的蜂窝网链路以及信令链路使用主载波，直联链路使用辅载波，从而有效的隔离了两类链路之间的干扰。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。