How to mantain POST data when using pagination in CI

Code:

public function ajaxsearch($start = 0) {

        $this->output->enable_profiler();

        

        $this->config->load('sicautogas');

        

        $this->load->model('Owners_model');

        $output_string = $this->Owners_model->AjaxSearch($this->security->xss_clean($this->input->post('keyword')), $this->config->item('max_per_page'), $start);

        

        $this->load->library('pagination');

        $config['base_url'] = site_url('users/ajaxsearch');

        $config['total_rows'] = count($output_string);

        $config['row_per_page'] = $this->config->item('max_per_page');

        

        $config['full_tag_open'] = '<div class="pagination"><ul>'; 

        $config['full_tag_close'] = '</ul></div>';

        $config['first_link'] = false;

        $config['last_link'] = false;

        $config['first_tag_open'] = '<li>';

        $config['first_tag_close'] = '</li>';

        $config['prev_link'] = '&larr; Previous';

        $config['prev_tag_open'] = '<li class="prev">';

        $config['prev_tag_close'] = '</li>';

        $config['next_link'] = 'Next &rarr;';

        $config['next_tag_open'] = '<li>';

        $config['next_tag_close'] = '</li>';

        $config['last_tag_open'] = '<li>';

        $config['last_tag_close'] = '</li>';

        $config['cur_tag_open'] = '<li class="active"><a href="#">';

        $config['cur_tag_close'] = '</a></li>';

        $config['num_tag_open'] = '<li>';

        $config['num_tag_close'] = '</li>'; 



        $this->pagination->initialize($config);

        $data['pagination'] = $this->pagination->create_links();

        $data['output_string'] = $output_string;

        

        $this->load->view('users/search', $data);

}

Code:

function AjaxSearch($keywords, $end, $start) {

        if ($this->session->userdata('regiones') != '') {

            $sql = "SELECT p.codigo, p.nb_propietario, p.cedula, p.telefono, p.direccion FROM tr023_propietario p, v002_geografico_codigos gc, tr003_geografico g WHERE p.co_geografico = g.codigo AND g.co_estado = gc.co_estado AND gc.region = '" . $this->session->userdata('regiones') . "' AND cedula LIKE UPPER(?) OR nb_usuario LIKE UPPER(?) GROUP BY p.codigo, p.nb_propietario, p.cedula, p.telefono, p.direccion";

        } else {

            $sql = "SELECT * FROM tr023_propietario WHERE (cedula LIKE UPPER(?)) OR (nb_propietario LIKE UPPER(?)) LIMIT ? OFFSET ?";

        }



        $query = $this->db->query($sql, array('%' . $keywords . '%', '%' . $keywords . '%', $end, $start));

        return $query->result();

}