We realize the non-split Bessel model of Novodvorsky and Piatetski-Shapiro in [22] as a generalized Gelfand-Graev representation of GSp(4), as suggested by Kawanaka in [17]. With uniqueness of the model already established in [22], we establish existence of a Bessel model for unramified principal series representations. We then connect the Iwahori-fixed vectors in the Bessel model to a linear character of the Hecke algebra of GSp(4) following the method outlined more generally in [3]. We use this connection to calculate the image of Iwahori-fixed vectors of unramified principal series in the model, and ultimately provide an explicit alternator expression for the spherical vector in the model. We show that the resulting alternator expression matches previous results of Bump, Friedberg, and Furusawa in [6]. We extend all results to GSp(2n), under the assumption that the aforementioned uniqueness property of the model holds for n > 2.

我们在[22]中将Novodvorsky和Piatetski-Shapiro的非分裂贝塞尔模型实现为GSp（4）的广义Gelfand-Graev表示，正如Kawanaka在[17]中提出的那样。利用已经在[22]中建立的模型的唯一性，我们建立了用于未扩展主序列表示的贝塞尔模型的存在。然后，我们按照[3]中概述的方法，将Bessel模型中的Iwahori固定向量连接到GSp（4）的Hecke代数的线性特征。我们使用此连接来计算模型中未分支主序列的Iwahori固定向量的图像，并最终为模型中的球形向量提供一个明确的交流发电机表达式。我们显示，结果的交流发电机表达式与[6]中的Bump，Friedberg和Furusawa的先前结果匹配。我们将所有结果扩展到GSp（2n），假设模型的上述唯一性对于n > 2成立。