function sms__unicode($message) {
  if (function_exists('iconv')) {
    $latin = @iconv('UTF-8', 'ISO-8859-1', $message);
    if (strcmp($latin, $message)) {
      $arr = unpack('H*hex', @iconv('UTF-8', 'UCS-2BE', $message));
      return strtoupper($arr['hex']) .'&unicode=1';
    }
  }
  return FALSE;
}

http://www.eggheadcafe.com/community/aspnet/79/10132316/utf8-to-ucs2.aspx

UTF-8 to UCS-2 SMS

PHP