C-band PAM-4 signal transmission using soft-output MLSE and LDPC code.

We propose a DSP scheme with soft-output maximum likelihood sequence equalizer (sMLSE) and low-overhead (8.51%) low density parity check (LDPC) code for C-band PAM-4 transmission. In order to apply LDPC code in conjunction with MLSE, the conventional hard-output MLSE is modified to have a soft-output value by using the Max-log BCJR algorithm. The feasibility of this approach is experimentally investigated in a 56 Gb/s C-band PAM-4 system. In order to investigate the advantages of the proposed scheme, we compare the performance of the sMLSE-LDPC code to that of MLSE-RS code. Relatively, additional OSNR gain of 0.6 dB ~2.1 dB is achieved. The variation of the relative OSNR gain depends on the burst errors, which originate from the power fading effect. By using an interleaver that spreads burst errors in time, one can see that the relative OSNR gain is improved as 1.6 dB ~2.1 dB. Using the proposed scheme with the interleaver, one can see that the 30 km transmission of 56 Gb/s PAM-4 in the C-band was experimentally demonstrated.

Henoch-Schoenlein nephritis in adults: a clinical and morphological study.

Renal prognosis is not clear in adults with Henoch-Schoenlein nephritis (HSN). Renal biopsy material from seventeen adult patients with HSN was studied by light-, electron-, and immunofluorescent microscopy, and a clinicopathologic correlation was made. The outstanding glomerular lesion was a mesangial IgA deposition, apart from the proliferative glomerulonephritis associated with segmental lesions or crescents. At the time of biopsy five patients (29%) presented with renal insufficiency complicated by nephrotic syndrome and/or hypertension. After a mean follow-up period of 3.2 years, ten patients showed complete recovery, two had minor urinary abnormalities, and five exhibited moderate proteinuria with or without hematuria. No patients had died nor developed chronic renal failure. Our data indicate that the outcome of HSN in adults is favorable similar to that in children. No initial clinical nor pathological features could be associated with a poor prognosis in this study. Further follow-up is needed in view of the unpredictable nature of this disease.