Let us assume I have $k$ (a fixed number) sensors in a wireless sensor network with unknown channel statistics $\{h_1,h_2 \ldots, h_k\}$.
In my system model, each of these $k$ sensors has an independent $n$-length binary ID sequence $x^i=\{x_1^i,x_2^i,\ldots, x_n^i\}, \forall i \in \{1,2,\ldots k\}$. This sequence is made of $0's$ and $1's$ (On-Off keying). Moreover, during the initial access phase, all the devices transmit this ID sequence synchronously.
At the receiver, during each of the $n$ channel-uses, we receive $y_j= \sum_{i=1}^{n}x_j^ih_i + n_j, \forall j \in\{1,2,\ldots n\}.$ Here, $n \sim \mathcal{N}(0,1), \forall j$ is the additive white gaussian noise.
Question 1: Using this model, can I estimate the channel statistics $h_i$? My initial though is $Yes!$ However, I searched a lot in google scholar to find papers that use 0-1 binary sequences (On-Off keying pilot sequences) for channel estimation in wireless communication scenarios. I could not find any. There are some optical communication papers though.
Question 2: Why is on-off keying bad for using as pilot sequences? In my case, I have to transmit them in the initial access phase anyways. Hence, I am thinking that though this channel estimate may not be a good one, it could be a coarse estimate which is useful. Do you agree?