It is best for the bed to have a headboard, and it is even better, if the headboard rests on the wall. This creates a feeling of protection and your sleep will be deep and you will feel a sense of placidity. If this is not possible you can create an artificial wall either fixed or mobile. The height of the wall does not need to reach the ceiling. It would be better though to reach at least the height of your shoulder and cover the length and your bedside tables.