Usually you would grant (or sell) the joint venture a licence to use your intellectual property. The licence will specify what rights and restrictions there are: for example, if the joint venture is only allowed to use your intellectual property within a certain territory. A licence, as opposed to a sale, may be more suitable to protect the ownership of intellectual property if the joint venture is not successful.
You will also need to ensure that there is clear agreement on the ownership of any new intellectual property created by the joint venture. Care needs to be taken over what will happen if the joint venture modifies your intellectual property: for example, by developing an improved version of a patented product. Otherwise, over time you could lose ownership of the modified intellectual property to the joint venture.
