what does "fixed multipath channel model" means?
Your "h" is a valid multipath channel impulse response.  It is a special case, though, in that it represents a multipath delay that is an exact multiple of your sample period.  Usually the delay will not be an exact multiple of the sample period.

I am not an expert on multipath channels, so hopefully someone else can chime in, but I think that the easiest way to generalize your multipath channel is to make the gain of the multipath complex rather than real.  The phase of the gain would alter the phase of your signal, simulating a non-integer delay.

If you really wanted to be hardcore about it you could use this answer on how to make fractional delay filters to create a filter that delays the signal by as much or as little as you want, and then add it to [1 0 0 0 0...] (the LOS channel) to get the complete multipath channel.