在PHP中实现WebSocket服务器可以使用以下步骤：

安装PHP WebSocket库，比如Ratchet：composer require cboden/ratchet

创建一个PHP文件，用来作为WebSocket服务器的入口文件，比如server.php，然后在文件中编写WebSocket服务器的代码，如下所示：

<?phprequire __DIR__ . '/vendor/autoload.php';use Ratchet\MessageComponentInterface;use Ratchet\ConnectionInterface;class WebSocketServer implements MessageComponentInterface {protected $clients;public function __construct() {$this->clients = new \SplObjectStorage;}public function onOpen(ConnectionInterface $conn) {$this->clients->attach($conn);echo "New connection! ({$conn->resourceId})\n";}public function onMessage(ConnectionInterface $from, $msg) {foreach ($this->clients as $client) {if ($client !== $from) {$client->send($msg);}}}public function onClose(ConnectionInterface $conn) {$this->clients->detach($conn);echo "Connection {$conn->resourceId} has disconnected\n";}public function onError(ConnectionInterface $conn, \Exception $e) {echo "An error has occurred: {$e->getMessage()}\n";$conn->close();}}$server = new \Ratchet\Server\IoServer(new \Ratchet\Http\HttpServer(new \Ratchet\WebSocket\WsServer(new WebSocketServer())),new \React\Socket\Server('0.0.0.0:8080', loop));echo "WebSocket server started\n";$server->run();

启动WebSocket服务器，可以使用命令行运行php server.php来启动服务器

现在WebSocket服务器已经可以接受和处理WebSocket连接了，可以通过WebSocket客户端连接到服务器并进行通信。