Rounding and Truncation in Radix (−2) Systems

Examination of rounding and truncation errors in radix (−2) systems establishes the following facts: 1) truncation error is 33 percent lower than in the positive radix case. 2) There is no 1-bit rounding algorithm. 3) The error bound of the standard (1-bit) positive radix rounding algorithm can be approached asymptotically by using more than one of the discarded bits. For N bits, this error bound is multiplied by 1 + (3. 2N−l)−1.