Combine soy sauce, lemon juice, olive oil, ginger, and pepper in a small bowl. Marinate salmon in half of marinade and vegetables in remaining half for 10 minutes. Remove Salmon from marinade and place on cedar sheet that has been soaking in water to soften. Place vegetables on top of salmon and fold cedar sheet edges around to close. Tye off with twine and grill on medium high grill for 5-7 minutes per side or until desired degree of doneness. Serve on plate still wrapped in cedar.