Autumn fruiting raspberries produce fruit on the new canes appearing each spring, so are cut down to the ground after cropping is over. Slightly confusingly, if not cut down, some of the canes survive the winter to produce a small crop the next summer.
Summer fruiting raspberries crop on the new canes produced the previous year, so only the canes which have fruited are cut down, leaving the new canes to bear the next year's fruit.
So, if you don't know which yours are, best way of covering both bases is to cut down any canes which have fruited (they will look woodier, and bear the remains of the fruit stalks.)
If they all appear to have borne fruit, odds are yours are an autumn fruiting variety.
In the longer term, you might want to consider starting a new raspberry patch, using suckers produced by the healthiest looking existing plants.
