Implement linked list version of Queue data structure. Define all operations that can be performed over a queue.

Sure, here is a Python implementation of a Queue using a linked list:

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

class Queue:
    def __init__(self):
        self.front = self.rear = None

    def is_empty(self):
        return self.front is None

    def EnQueue(self, item):
        temp = Node(item)

        if self.rear is None:
            self.front = self.rear = temp
            return
        self.rear.next = temp
        self.rear = temp

    def DeQueue(self):
        if self.is_empty():
            return
        temp = self.front
        self.front = temp.next

        if(self.front == None):
            self.rear = None
        return str(temp.data)

Here are the operations that can be performed over a queue:

1. EnQueue(item): Adds an item to the queue. If the queue is empty, it adds the item and sets both front and rear to the new item. If the queue is not empty, it adds the item at the end and updates the rear.

2. DeQueue(): Removes an item from the queue. The items are popped in the same order in which they are pushed. If the queue is empty, returns None. If the queue has only one item, it removes it and sets both front and rear to None. If the queue has more than one item, it removes the front item and sets front to the next item.

3. is_empty(): Checks if the queue is empty. Returns True if the queue is empty, False otherwise.