AWGN BPSK rate LCAS 44Qp1kHz kbit kbyte GQp729Qp1 19200 anaicut subarrays oversampling Jayankondam Sonamura channel baud 324M GQp711 precoding B8ZS bit Bitrate QQAM 380A bitstream PLL BER kilobits VBR burstiness Uthukuli Tirupathur Thenkarai Singampuneri Pallapalayam