Badminton competition, 7 teams, how to arrange the competition system?

Single round robin system: it is divided into seven rounds, and the ranking is determined by the number of wins and losses and points after the end. ?

The first round: 1-0, 2-7, 3-6, 4-5, where 0 stands for bye and each number stands for a team?

Second round: 0-5, 6-4, 7-3, 1-2?

The third round: 2-0,3-1,4-7,5-6?

Round 4: 0-6, 7-5, 1-4, 2-3?

Round 5: 3-0, 4-2, 5- 1, 6-7?

Round 6: 0-7, 1-6, 2-5, 3-4?

Round 7: 4-0,5-3,6-2,7-1?

Or draw lots for seven teams and divide them into three teams and four teams. ?

One team in a group of three teams will have a bye (draw lots to decide who will have a bye), and the other two teams will decide the winner in three games and two losses, and the winner will be decided in the same bye. ?

The four teams are divided into two groups, each group decides the winner with two wins in three games, and the winner with two wins in three games. ?

The last two teams will decide the champion.