To facilitate a broad range of experimental research on novel protocols and application concepts, we consider an indoor wireless testbed to emulate the performance of real-world networks. A fundamental issue for emulation is the replication of communication links of specified quality. In particular, we need to replicate on the testbed, for every link in the real world, a communication link whose received signal-to-interference-and-noise-ratio (SINR) matches the corresponding link signal-to-noise-ratio (SNR). In this paper, we focus on the downlink SNR mapping associated with a network with a single access point (AP). Four indoor wireless propagation models (commercial buildings with/without line-of-sight path and residential buildings with/without line-of-sight path) and two types of spatial distributions (uniform distribution inside a circular cell and uniform distribution along a line) have been investigated. Based on the characteristics of the indoor testbed, we propose a mapping method with one AP and one interferer, which separates the task into two phases: In the first phase, the best location and transmission power for the interferer node are determined; in the second phase, the topology of receiver nodes is configured by a minimum weight matching algorithm. Through analysis and simulations, we find that when the interferer node is located on the corner across from the AP, we can achieve a mapping range on the order of 57dB and an average root-mean-square (RMS) mapping error less than 1 dB.